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Video: Using Sheep to Terminate Cover Crops in Organic Farming

New/updated @ eXtension - Tue, 06/11/2019 - 09:49

This video describes ongoing interdisciplinary research that explores how the use of domestic sheep—rather than traditional farming equipment—to manage fallow land and terminate cover crops may enable farmers who grow organic crops to save money, reduce tillage, manage weeds and pests, and reduce the risk of soil erosion. Researchers from Montana State University and North Dakota State University are working on a USDA-National Institute of Food and Agriculture (NIFA) Organic Transitions project: Reducing Tillage in Organic Crop Systems: Ecological and Economic Impacts of Targeted Sheep Grazing on Cover Crops and Weed management, Soil Health and Stability, Carbon Sequestration and Greenhouse Gas Emissions. Additional information about the project is available on the Montana State University website here.

Researchers: Fabian Menalled, Patrick Hatfield, Perry Miller, Anton Bekkerman, Devon Ragen
Camera: Steve Spence, Casey Kanode, Jared Berent
Editing: Case Kanode, Steve Spence

Recording available on YouTube at https://www.youtube.com/watch?v=Y5w25UgWMTs

This is an eOrganic article and was reviewed for compliance with National Organic Program regulations by members of the eOrganic community. Always check with your organic certification agency before adopting new practices or using new materials. For more information, refer to eOrganic's articles on organic certification.

eOrganic 13042

Food Hub Feasibility in Oregon’s Mid-Willamette Valley: Interviews with Conventional and Organic Small and Mid-Sized Farmers

New/updated @ eXtension - Mon, 06/10/2019 - 15:28

eOrganic authors:

Eliza Smith, Oregon State University

Javier Fernandez-Salvador, Oregon State University

Introduction

A food hub is a centralized location, either brick and mortar or online-based, that connects farmers and food buyers. Food hubs are becoming an increasingly common model for producers to sell their products in local markets (Colasanti et al., 2018). Food hubs may be a website where farmers post their products for sale, or a physical location that provides services to growers such as aggregation and distribution management, a commercial kitchen, or a USDA meat-processing facility (Colasanti et al., 2018). Food hubs may also be a vehicle to educate the community on the value of buying products from local producers (Cantrell and Heuer, 2014). Food hubs can be especially beneficial to small growers because they provide infrastructure and services that those growers may not have the means to provide on their farms (Conner et al., 2017). In fact, the 2017 Food Hub Survey showed that over 90% of food hubs had “increasing small and mid-sized producers’ access to markets” included in their mission (Colasanti et al., 2018). A previous study showed that food hubs are most successful in metropolitan areas because of their accessibility to growers, wholesale buyers, and retail consumers (Fischer et al., 2013). For example, in Portland, Oregon the nonprofit Ecotrust organizes a physical location food hub, The Redd on Salmon Street.

Introduction to the Food Hub Feasibility Survey

Salem is the capital of Oregon with a population of 168,000. It is the second-largest city in Oregon, behind Portland. In 2016, the City of Salem proposed a food hub as one option to revitalize a low-income area that was slated for improvement with urban renewal dollars. The city collaborated with ECONorthwest consultants and the local OSU Extension Service Small Farms Program to develop, conduct, analyze, and present the results of a survey of small and mid-sized farmers (both organic and conventional) in the Salem area to assess their interest in a potential food hub. 

The survey consisted of two sections with both multiple-choice and open-ended questions. The first section included general questions about the farming operation (location, acreage, what products they sell, when the products are available for sale, and where they currently sell their products). The second section was designed to assess the farmers' interest in a food hub in Salem, and included questions about farmers' interest in increasing local sales, whether they thought a food hub was needed in the Mid-Willamette Valley, and their top farming challenges. The second section also asked what services a food hub could provide that would benefit them, as well as whether they would be interested in participating in a food hub, where they would ideally like it to be located, and barriers they see to their participation in a food hub. Since this survey was only an initial inquiry to see whether the farmers were interested in a food hub, more specific questions like what farmers would pay for services provided by the food hub were not included.

A total of 19 small and mid-sized farmers (10.5% of the estimated total in the region) were interviewed for the survey, from September 2016 to March 2017; 18 on-site at their farms and one over the phone. While the survey was being developed, a database of small farmers in Oregon's Mid-Willamette Valley was compiled from internet searches, extension contact lists, and county tax assessor data. Survey participants were contacted from this database. As in most research that includes interviews or surveys, the data was limited to responses from farmers that chose to participate. Many of the farmers who responded to the request for an interview had been previously involved with the OSU Extension Service (participated in research, answered surveys, hosted workshops, etc.). A breakdown of what crops/products the survey participants grew or produced is shown in Table 1. 

Table 1. Number and percentage of participants that farm and sell various products 

Sales outlet On-farm Farmers' Market CSA Restaurant Grocery (retail) Institutions Wholesale Online  Other Number of participants that sell via that outlet 7 5 7 6 4 0 8 0 2

Seven of the farmers interviewed were certified organic and the remaining 12 were not. The non-organic farmers were a mix of six conventional farms and six farms that were practicing alternative agriculture (no-spray, ecological, etc.) but were not certified organic. 

The same interviewer conducted the interviews with producers for consistency of data collection. Data were analyzed in one and two-way tables by breaking the participants into sub-groups based on farm location, years of farming experience, farmed acreage, products farmed and sold, and organic certification status.

Key Findings from the Survey
  • Three-quarters of the farmer participants had heard the term food hub before the survey. It was important to ensure that all of the survey participants had a common understanding of a food hub, as that would affect their responses.
  • Participants sold their products through a variety of outlets, ranging from farmers' markets to wholesale (Table 2).

    Table 2. Sales outlets that participants use to sell their products

Service the food hub could provide Responded that it would be helpful Community Education 84% Value added processing  74% Aggregation 68% Direct Sales 68%

  • All but one of the farmers interviewed for the survey were interested in participating in a food hub in Salem, Oregon. The producer that was not interested in participating had a variety of long term wholesale buyers and was not looking to expand farm sales.
  • Community education was the most common option chosen by all participants interested in a food hub when asked what services they would like a food hub to provide (Table 3). Value-added processing, direct sales, distribution, and aggregation were of secondary interest to participants (Table 3).

Table 3. Services that farmers said would be helpful as part of a food hub, ranked from highest to lowest percentage of respondents. 

Service the food hub could provide Responded that it would be helpful Community Education 84% Value added processing  74% Aggregation 68% Direct Sales 68% Distribution 63% Transportation 58% Cold Storage  58% Marketing Support 58% Local label 53% GAP/food safety cert. assistance 47% USDA meat processing facility 42% Organic certification assistant 37% Freezer storage  26% Light processing 26% Dry product handling 21%

  • All of the certified organic farmers grew mixed vegetables, which shaped many of their responses from product availability to services they want the food hub to provide. Only 58% of the non-organic farmers grew mixed vegetables.
  • All of the meat producers surveyed said processing is their primary farming challenge because of the limited number of USDA meat-processing facilities in the region that will work with small producers. All seven meat producers surveyed said a USDA meat-processing facility was their top priority for a service the food hub could provide. Two of the seven meat producers surveyed were certified organic. For their meats to be sold as organic after processing, the facility would have to be certified organic in addition to being USDA-certified.  
Farmer Concerns about a Food Hub
  • Three main concerns that emerged from the interviews with both organic and non-organic farmers about participating in the food hub were: 1) they would need to set their prices too low, 2) lack of consumer demand for their products in the geographical area around the food hub, and 3) too much competition from larger farms who would also participate in a food hub.
  • Both organic and non-organic farmers were concerned that end-consumers and/or buyers would not go to the food hub to buy their products. Considering that, they requested that the food hub provide community education about the value of buying local agricultural products.
  • The participant with one of the largest farms in the survey (100+ acres) that has robust transportation and wholesale distribution systems for their organic produce, expressed concern that the transportation limitations of smaller farmers due to fewer vehicles and employees (regardless of certification status) would limit large-volume accounts at the food hub.
  • Large-volume buyers (wholesale) commonly have an interest in purchasing goods at rates lower than direct-to-consumer prices. This decrease in profit margin would not prove sustainable or enticing for small and mid-sized farm operations, causing many of the survey participants to doubt or question the implementation of a similar business model, as reported in the ECONorthwest writeup of the survey results for the City of Salem (ECONorthwest, 2017).
Comparing Organic and Non-organic Survey Participants

It is important to compare the responses from these two groups of participants because organic and non-organic products command different prices, which we expected may affect the farmers' responses.

  • On average, the organic growers had been farming more years than the non-organic farmers surveyed.
  • A much higher percentage of organic farmers did not think a food hub was necessary in the Mid-Willamette Valley (29%) as compared to non-organic farmers (8%). Many of the organic farmers said that they would gladly participate in a food hub, but were worried that there wouldn't be enough people or companies in Salem to buy their products. A lot of the organic farmers take their products to Portland, the largest metropolitan area in the state, to sell them where the demand for organic foods is more mainstream and verified by existing organic sales in the city. Producers surveyed were concerned that it would be more difficult to sell their organic products in Salem and get the price they need for them.
Consumer Demand
  • The report presented by ECONorthwest stressed that overall, consumer energy for the local foods movement is not as strong in Salem as in other parts of the Mid-Willamette Valley (2017). This demonstrates a need for end-consumer education about buying local agricultural products, which was a point that all of the farmers mentioned and considered important.
  • Our study supported this finding, as many survey participants cited a potential lack of demand for locally produced foods by consumers as a factor that could contribute towards hesitation about building a food hub.
Conclusion

Food hubs may be useful and important resources for farmers looking for new local outlets to sell their products. This survey indicated a great interest from small and mid-sized farmers in participating in a food hub. It also collected a variety of concerns from the farmers about price point, consumer education, and competition from larger farms. As backed by other studies and farmer responses, we determined that for a food hub to be successful, farmers' interest in participating must be met by sufficient consumer demand for local agricultural products, and this may be particularly true for organic products. Establishing a food hub is a large undertaking and conducting preliminary surveys to gauge interest from both farmers and consumers is an important first step before investing in more comprehensive assessments. When farmers are considering participation in a food hub, it is important to ask many of the same questions that a survey like this would pose, such as: What services will the food hub provide? What are your price requirements to sell at a food hub? Is the food hub in a convenient location? And, do you see any potential barriers to your participation in a food hub?

Additional Resources
  • National Good Food Network Food Hub Center (The Wallace Center). Provides a variety of resources, including: webinars about existing food hubs, a link to the USDA food hub directory, a food hub consultant database, funding sources for food hubs, and research about food hubs.
  • USDA Regional Food Hub Resource Guide. Summary of what a food hub is, its impacts, economic viability, potential barriers to growth and possible solutions to those barriers. Starting on page 29, there are listings of various funding sources available to help establish a food hub.
  • USDA Agricultural Marketing Service. General information about food hubs and links to resources. The USDA AMS Food Hub Map is a visual representation of the USDA food hub directory.
  • A Food Hub Facility Design Case Study. A case study of the establishment of the Tuscarora Organic Growers food hub in Pennsylvania, focusing on the physical building of the food hub. Includes building dimensions and operational expenses.
  • Healthy Food Access Portal: Food Hubs. This webpage provides an overview of food hubs, including resources, strategies, challenges and food hub success stories from all over the U.S.
References and Citations

This is an eOrganic article and was reviewed for compliance with National Organic Program regulations by members of the eOrganic community. Always check with your organic certification agency before adopting new practices or using new materials. For more information, refer to eOrganic's articles on organic certification.

eOrganic 25213

Fire Blight Control for Organic Orchards: Moving Beyond Antibiotics

New/updated @ eXtension - Mon, 06/10/2019 - 15:19

eOrganic author:

David Granatstein, Washington State University

Introduction

Fire blight is a serious disease of apple and pear caused by the bacterium Erwinia amylovora. It originated in the United States and is now found in many parts of the world. Most domesticated apple and pear cultivars have some degree of susceptibility to infection. Damage is not cosmetic, but reduces crop yield and may kill entire trees. Prior to implementation of the National Organic Program (NOP), a number of U.S. certifiers allowed the use of the antibiotics oxytetracycline and streptomycin for control of this disease, as they are naturally occurring molecules produced by soil microorganisms. However, the NOP classified them as synthetics but allowed their use for fire blight control only. The National Organic Standards Board has voted to remove these antibiotics from the national list of allowed materials, and their use will be prohibited after October 2014. Due to the potentially devastating damage from this disease, organic apple and pear growers are looking for viable non-antibiotic control measures.

Breeding for Resistance

The ideal solution to fire blight is genetic resistance bred into both the scion (fruit-bearing portion) and rootstock of the tree. The ‘Geneva’ series apple rootstocks do exhibit a high level of resistance to fire blight, but do not confer resistance to the scion grafted onto them. No highly resistant scion cultivars have been identified that also have the requisite fruit quality characteristics needed for commercialization. Several cultivars of pear developed by the USDA and Agriculture and Agri-Food Canada do exhibit increased resistance. Breeding programs are looking at sources of resistance in other wild apple species that have better fruit quality potential, and progress can be expected over the next 10-15 years.

Biological and Chemical Control

Application of antibiotics has been the primary practice used to manage fire blight for more than 50 years. Antibiotics are effective and fast-acting, and can be used in concert with disease prediction models (e.g., COUGARBLIGHT, MARYBLYT) so treatments may only be made when risk of infection is high. Research on biological control practices has been conducted since the 1980s, and several products have been commercialized such as Blight Ban®A506 (Pseudomonas fluorescens strain A506). However, until recently, no products exhibited efficacy similar to antibiotics. In 2012, the yeast product Blossom Protect™ (Aureobasidium pullulans) debuted in the U.S. market and has performed well for the past two seasons. Other materials such as Serenade® MAX (Bacillus subtilis), Double Nickel 55™ (Bacillus amyloliquefaciens), and soluble copper (e.g., Cueva®) are also available and organic-compliant, providing growers with several options to combine into an integrated fire blight management program. In addition, lime sulfur, commonly used by apple growers as a blossom thinner to reduce crop load, has been shown to exert control of fire blight when applied during bloom.

IMPORTANT: Before using any pest control product in your organic farming system:

  • Read the label to be sure that the product is labeled for the crop and pest you intend to control, and make sure it is legal to use in the state, county, or other location where it will be applied

  • Read and understand the safety precautions and application restrictions

  • Make sure that the brand name product is listed in your Organic System Plan and approved by your USDA-approved certifier. If you are trying to deal with an unanticipated pest problem, get approval from your certifier before using a product that is not listed in your plan—doing otherwise may put your certification at risk.

Note that OMRI and WSDA lists are good places to identify potentially useful products, but all products that you use must be approved by your certifier. For more information on how to determine whether a pest control product can be used on your farm, see the article, Can I Use This Input On My Organic Farm?

Time to Test Alternatives

Organic growers exporting fruit to the European Union were prohibited from using antibiotics, and they tested various approaches and products that were successful in certain locations and with certain cultivars. More recently, an organic fire blight control project for Oregon, Washington, and California, led by Dr. Ken Johnson of Oregon State University, has made significant progress in testing many of these materials and evaluating their efficacy as well as potential combinations and timings for best results. Growers need to test alternative controls on their own sites with their specific cultivars to prepare for the loss of antibiotics.

The following resources are available to help organic growers learn more about fire blight control alternatives. These include eOrganic webinars by Dr. Johnson, a new publication Grower Lessons and Emerging Research for Developing an Integrated Non-Antibiotic Fire Blight Control Program in Organic Fruit from The Organic Center, a recent journal article (Johnson and Temple, 2013) Evaluation of strategies for fire blight control in organic pome fruit without antibiotics), and an annotated powerpoint by Dr. Johnson summarizing the research progress to date. The applicability of the information presented in these various sources will undoubtedly vary by region, crop, orchard age, training system, and cultivar, so growers should be conducting some simple field evaluations of their own while the research proceeds.

One issue not fully resolved is that of fruit marking or russetting—a cosmetic defect on the skin of fruit caused by phytotoxicity of control materials when applied at a susceptible fruit stage. If a material provides a high level of fire blight control but russets fruit and renders it unmarketable in commercial channels, then it will not be an acceptable material for most growers.

Conclusion

Significant progress has been made in the past several years on non-antibiotic fire blight control methods that would be compliant on organic orchards. Well-vetted recommendations are not yet available, and thus growers need to be testing these new materials and ideas on their own orchards in the meantime. Ultimately, genetic resistance to the disease will provide the most sustainable alternative but this is likely decades away. However, growers can test small plantings of some of the reputedly more resistant cultivars now, observe their resistance, fruit quality, and horticultural needs, and develop their own markets for those new cultivars. The demand for organic apples and pears continues to increase, and growers need well-proven fire blight control approaches to allow them to respond to this demand while minimizing risks from the disease.

References and Citations Additional Resources

This is an eOrganic article and was reviewed for compliance with National Organic Program regulations by members of the eOrganic community. Always check with your organic certification agency before adopting new practices or using new materials. For more information, refer to eOrganic's articles on organic certification.

eOrganic 10624

Current and Future Prospects For Biodegradable Plastic Mulch in Certified Organic Production Systems

New/updated @ eXtension - Sat, 06/08/2019 - 19:40

eOrganic authors:

Dr. Andrew T. Corbin Ph.D., Washington State University

Dr. Carol A. Miles Ph.D., Washington State University

Jeremy Cowan, Washington State University

Dr. Douglas G. Hayes Ph.D., University of Tennessee

Dr. Jennifer Moore-Kucera Ph.D., Texas Tech University

Dr. Debra A. Inglis Ph.D., Washington State University

Introduction

Certified organic farmers are currently allowed to use conventional polyethylene mulch, provided it is removed from the field at the end of the growing or harvest season. To some, such use represents a contradiction between the resource conservation goals of sustainable, organic agriculture and the waste generated from the use of polyethylene mulch. One possible solution is to use biodegradable plastic as mulch, which could present an alternative to polyethylene in reducing non-recyclable waste and decreasing the environmental pollution associated with it. This article explains how biodegradable plastic mulches are made; how biodegradability is measured; current techniques on evaluating biodegradable mulches; and research and policy progress to date. The purpose is to inform agricultural professionals, farmers, and policy makers about the suitability of biodegradable plastic mulches for use in certified organic agriculture. A glossary is provided at the end of this publication which includes definitions and terms commonly used when describing biodegradable plastic mulch. Terms included in the glossary are in bold text.

Plastic mulch films in agriculture

Polyethylene plastic mulch is widely used for crop production in the U.S. and worldwide, because it controls weeds, conserves soil moisture, increases soil temperature, improves crop yield and quality, has a relatively low cost, and is readily available (Schonbeck and Evanylo, 1998; Corbin et al., 2009; Miles et al., 2012). However, the sustainability of producing crops through the use of polyethylene mulch has been called into question because polyethylene mulch is made of non-renewable, petroleum-based feedstock, is generally only used for one growing season, and cannot be recycled in most regions. Recycling is limited because the mulch may be contaminated with soil and agrochemicals, specialized baling equipment is required before hauling, and facilities for recycling are often a long distance away. (Garthe and Kowal, 1993).

The high volume of waste generated by polyethylene mulches both in the field and in landfills raises many concerns (Figure 1). For example, in 2004 in the U.S., 143,000 tons of plastic mulch were disposed. While much of this waste entered the landfill at a cost to growers of up to $100 per acre, some was burned on site (Shogren and Hochmuth, 2004). Burning of polyethylene mulch can have undesirable environmental impacts, such as the release of dioxins as an airborne pollutant (Levitan, 2005; Lemieux, 1997). While there are no federal regulations restricting the open burning of plastics, the practice is banned in several states or counties in the U.S. (EPA, 2011; OAR, 2013). Utilization of polyethylene mulch by soil microorganisms in landfills is negligible, with the microbial conversion and abiotic oxidation products possibly consisting of environmentally harmful chemicals such as aldehydes and ketones (Hakkarainen and Albertsson, 2004). The use of biodegradable mulches could save significant labor and disposal costs, conserve resources, and decrease pollution (Smith et al., 2008).

 

Figure 1. (a) Typical post-season polyethylene plastic mulch waste in the field.  (b) Ready for transport to the landfill. Photo Credit: C. Miles, Washington State University. From Corbin et al., 2013.

For these reasons, both new and experimental mulches that are designed to biodegrade (mineralize) fully into carbon dioxide and water, have been developed by industry and academic institutes over the past 25 years. To be a viable alternative in organic crop production, biodegradable plastic mulch must perform comparably to polyethylene mulch, especially in regard to durability and the ability to block light to prevent weed germination. Ideally, once the biodegradable mulch's useful service life has ended, it is plowed into the soil where it should degrade. In the short-term, the mulch should lose mechanical strength and undergo a reduction in the degree of polymerization (Figure 2), or depolymerization, thereby making the polymer molecules accessible to microorganisms. Ultimately, the mulch should undergo at least 90% mineralization within a two-year period.

Figure 2. (a) Starch-based biodegradable plastic mulch (BioAgri®) in experimental field plots during harvest, 135 days after laying mulch. (b) 9 months post-harvest on soil surface, 348 days after laying mulch. (c) 9 months post-incorporation, 348 days after laying mulch. Photo Credits: J. Cowan (2a) and C. Miles (2a, 2b), Washington State University. From Corbin et al., 2013.

How are biodegradable plastic mulches produced?

Many biodegradable plastic mulches that are commercially available are films made from plant starch; these are prepared using conventional plastics processing technology. However, due to the poor mechanical properties of starch, including its brittleness, starch must be blended with other polymers and/or plasticizers. Products currently on the market that contain plant starch include Biomax TPS (DuPont, USA), Biopar (Biop, Germany), Paragon (Avebe, Netherlands), BiosafeTM (Xinfu Pharmaceutical Co., China), Eastar BioTM (Novamont, Italy), Eco-Flex® (BASF, Germany), Ingeo® (NatureWorks, USA) and Mater-Bi® (Novamont, Italy) (Hayes et al., 2012).

Two polymers that may have a future role in biodegradable plastic mulches are polylactic acid (PLA) and polyhydroxyalkanoate (PHA). PLA is a highly versatile, biodegradable polyester derived from 100% renewable resources such as corn and sugar beet starch, and offers great promise in a wide range of commodity applications (Drumright et al., 2000). Starch is converted by microorganisms into lactic acid through fermentation. Lactic acid molecules are then linked together into long chains called polymers. PLA is a relatively inexpensive biopolymer to manufacture (~ $0.95 per lb), and can be produced in large quantities (Endres and Siebert-Raths, 2011). The PLA polymer is highly attractive for biological and medical applications because it can be spun into filaments that can be used to make textiles or films (Gupta et al., 2007). PHAs are promising biodegradable plastics that have been highlighted as "green" polymers because they are made from renewable resources in a one-step process by the bacterial fermentation of sugars and/or lipids (Kaihara et al., 2005; Posada et al., 2011; Hayes et al., 2012). PHA polymers may be produced from microbes or plants; but currently, microbes are the primary source (Keshavarz and Roy, 2010).

New experimental agricultural mulches have been prepared from PLA and PHA blends using nonwovens textile technology (Wadsworth et al., in press). Nonwovens are manufactured sheets, webs or bats (wadded rolls) of directionally or randomly oriented fibers or filaments, bonded together. Nonwovens may be manufactured by spunbond or meltblown processes. In the spunbond process, polymers are first melted and then extruded through spinnerets, producing filaments which are cooled and laid down on a conveyer belt to form a web. In the meltblown process, polymers are extruded through a die or spinneret, and the filaments are stretched, dispersed, cooled, and then collected on a roll. Generally, meltblown nonwovens have smaller fiber sizes and have lower mechanical strength than spunbond nonwovens (Hayes et al., 2012).

Some processes that are used to form biodegradable polymers utilize additives, such as nucleating agents (chemical substances incorporated in plastics for the growth of crystals in the polymer melt), plasticizers, coloring agents, performance additives, and/or lubricants to improve the mechanical properties of the plastic. The environmental impact of many additives may be a major concern in organic as well as conventional crop production. Some additives are derived from petroleum and/or are chemically processed, and are therefore considered synthetic material by National Organic Program (NOP) standards (Hayes et al., 2012; NOS, 2012), which has prevented their use in U.S. organic agriculture. In addition, the NOP considers PLA to be synthetic because PLA is chemically polymerized (Briassoulis and Dejean, 2010). While the PHA polymer is made directly by microorganisms in the fermentation process (thereby considered "natural" by the NOP), it is highly crystalline, making its end product more brittle, and less desirable, unless blended with PLA or other co-polymers (Hayes et al., 2012).

What constitutes biodegradability?

Many agricultural plastics are advertised as "biodegradable"; however, such claims need to be evaluated carefully. For a manufacturer to employ the claim of biodegradability, a set of specified standards need to be met. ASTM International (formerly known as the American Society for Testing and Materials) has prepared a series of standards for "compostable plastics" to measure biodegradability under municipal or industrial composting conditions, referred to as ASTM D6400.

The ASTM D6400 specification encompasses several ASTM standardized tests, such as the "inherent biodegradability" of the plastic material via ASTM D5988-03. This test measures the microbial conversion of the plastic’s carbon (C) atoms to carbon dioxide (CO2), over time. A standard that is embedded in ASTM D6400 specifies that 90% of C atoms must be mineralized, that is, converted to CO2 within 180 days by microorganisms (ASTM, 2003). In the laboratory, CO2 release is measured through a relatively inexpensive titration method.

Biodegradability-related standards are comprised of criteria that address the following three issues:

(i) The conditions of the system —industrial-scale composting or anaerobic digestion, soil, marine, etc.
(ii) The time frame—number of days for carbon molecules in plastic to be converted to CO2.
(iii) The fraction of carbon atoms that are to be fully mineralized by microorganisms – generally expected to be at least 90%.

Many mulches claiming to be "biodegradable" are actually "compostable", i.e., able to fulfill the requirements of ASTM D6400, or related standards. Moreover, no standard currently exists for measuring the biodegradability of plastics incorporated into soil under field conditions. To meet this need for measuring biodegradability within the soil, ASTM International is developing a new standard (Work Item 29802) entitled Aerobically Biodegradable Plastics in the Soil Environment (ASTM, 2012). In this new standard, biodegradable mulches must break down into CO2, water and environmentally benign substances within one or two years, leaving no harmful residues. The ability of existing and emerging biodegradable plastic mulch films to meet these criteria in the soil environment has been the topic of several investigations (Harding et al., 2007; Hayes et al., 2012; Miles et al., 2012; Hoshino et al., 2007; Kapanen et al., 2008; Kijchavengkul et al., 2008; Kyrikou and Briassoulis, 2007; Mohee and Unmar, 2007; Tachibana et al., 2009; Wadsworth et al., 2009), and continues to be researched.

Evaluating degradation/deterioration vs. biodegradation

The term degradation is used to denote changes in physical properties caused by chemical reactions involving bond scission in the macromolecule (polymer). Biopolymer degradation includes changes of physical properties, caused not only by chemical reactions, but also by physical forces. Because the term polymer degradation involves a deterioration in the functionality of polymeric materials, "degradation" and "deterioration" are often used interchangeably (Schnabel, 1992). ASTM and the International Organization for Standardization (ISO) define degradation as an irreversible process leading to a significant change of the structure of a material, typically characterized by a loss of properties (e.g. integrity, molecular weight, structure or mechanical strength) and/or fragmentation, as affected by environmental conditions, proceeding over a period of time, and comprising one or more steps (Krzan et al., 2006).

The efficiency of the plastic degradation process varies by environment and may also be affected by the concentration of chemicals present that may react with the plastic. Environmental factors such as temperature, moisture level, atmospheric pressure, concentrations of acids and metals, and light exposure all have an effect on the rate of degradation that is due to microorganisms i.e., biodegradation (Kyrikou and Briassoulis, 2007). However, weight loss and other physical, chemical and mechanical property reductions in biodegradable plastic do not comprise the full measure of percent biodegradation unless microbial utilization of C (via CO2 conversion) is also measured. Percent biodegradation is the measure of the rate and amount of CO2 released from the total C input (from the mulch), and is a direct measure of the amount of C being utilized by the microbial community (Narayan, 2010).

While biodegradation measurements in the field or laboratory are relatively straightforward for well equipped and trained scientists, they are impractical for farmers to perform. Until the scientific community and the NOP can provide farmers with repeatable results on field performance of biodegradable plastic mulch products that are recommended for organic use, it may be advisable for farmers to monitor the degree of mulch degradability (see limitations below). Miles and others (2012) assessed percent visual deterioration (PVD) of biodegradable plastic mulch under field conditions and counted the number of rips, tears and holes (RTH) in a designated portion of the mulch twice per month. PVD proved to be a fair assessment of mulch deterioration while RTH did not. Cowan (personal communication) evaluated PVD during two late-summer broccoli seasons, and then measured mulch fragment recovery over the course of one year after mulches were tilled into the soil. At each of five sampling times, three random four-inch-diameter x six-inch-deep soil samples were collected (using a golf cup cutter) per 28-foot of mulch treated bed. Samples were sieved to retrieve mulch fragments,and photographs of mulch fragments were digitally analyzed to measure average area of individual fragments, fragment counts, and total fragment area. Findings indicated that post-tillage mulch recovery can be measured using this method. Two of the mulch products evaluated, Crown 1 and BioAgri, were recovered at 0% and 34%, respectively, within 13 months after soil incorporation.

Moore-Kucera et al., (in prep.) as part of a three-year field study, buried mesh bags containing a 4 inch square of biodegradable plastic mulch (previously weathered in the field for one growing season) and 300-400 grams of native agricultural soil four inches deep in field plots at three locations (Knoxville, TN, Lubbock, TX, and Mount Vernon, WA). At each location, one mesh bag was removed from replicated plots every 6 months for 24 months and the residual mulch pieces were evaluated for percent surface area remaining (Figure 3). Results varied widely by location, each with unique physical (light, temperature, moisture, wind, etc.), chemical (pH) and soil microbial attributes (Corbin et al., 2013; Bailes et al., in press; Moore-Kucera, 2012). For further information on experimental mulch degradation in the field, see the Washington State University Factsheet Using Biodegradable Plastics as Agricultural Mulches (Corbin et al., 2013). Although these types of field measurements will not determine percent mulch biodegradation per se, they are relatively simple sampling procedures that farmers, Extension or Agricultural Agency personnel can perform without the use of laboratory equipment, and provide a visual estimate of degradation/deterioration and mulch recovery in the field. 

Figure 3. Samples of starch-based biodegradable plastic mulch (BioTELO®) recovered after twenty-four months burial in the field at three experimental locations. Photo credit: J. Moore-Kucera, Texas Tech University.

Biodegradable plastic mulch limitations in certified organic production

In the U.S., organic crop producers have not been able to use currently available biodegradable plastic mulch products because these products did not conform to NOP standards. To be acceptable for organic production, biodegradable plastic mulch must be entirely composed of constituents derived from natural resources (bio-based), cannot contain synthetics such as petroleum-derived ingredients or additives, and cannot be chemically modified during the manufacturing process (NOS, 2012; Corbin et al., 2013; Corbin et al., 2009).

An additional requirement to meet the organic standards is that feedstocks, such as corn, used to produce the polymer, must be free of genetically modified organisms (GMOs). Similarly, any polymer made from microbial fermentation, such as PHA, must be produced by organisms that have not been genetically modified. Biodegradable plastic mulch manufacturers must certify that their feedstocks and microbial fermentation processes are GMO-free; however, there is no available test to verify GMO byproducts in the final product. While there is no specific NOP policy on GMOs in biodegradable plastic feedstock, the NOP has developed an ad-hoc committee to clarify the GMO issue.

Another requirement for use in certified organic production is that the resins and any inert additives used in the processing and formulation of biodegradable plastic mulch products must be identified and compared to the National List of allowable substances. The designation of ingredients as "proprietary" is not adequate for review and approval by the National Organic Standards Board (NOSB) – the sole authority to recommend adding or removing materials from the National List of acceptable and prohibited substances.

Finally, any biodegradable plastic mulch that may eventually be approved for use by the NOP must completely biodegrade into carbon dioxide, water, and microbial biomass within a "reasonable" timeframe without forming harmful residues or by-products. Sufficient data will be needed to verify that each biodegradable mulch is truly biodegradable in an agricultural system.

A growing contingency of manufacturers and organic farmers who wanted this interpretation of the NOP standards to be revised so that biodegradable plastic mulches are included on the National List of allowable "synthetic" substances has recently gained recognition (NOSB, 2012). As a precedent, the organic standards in Canada and the European Union (E.U.) have allowed some use of currently available biodegradable plastic mulches. In 2012, the Biodegradable Products Institute (BPI) petitioned the NOP to allow the addition of biodegradable plastic mulch under section 205.206 (c) of the National Organic Standards Biodegradable Plastic Mulch Made from Bioplastics: without removal at the end of the growing or harvest season (BPI, 2012). In October 2012, the NOSB voted 12-3 to formally recommend the NOP approve biodegradable plastic mulch in organic production (NOSB, 2012). Included in this recommendation is a requirement that organic growers take appropriate actions to ensure complete degradation (NOSB, 2012) of biodegradable plastic mulch products on their farms, underlining the importance of evaluating on-site degradation. As of 2013, the recommendation has yet to be accepted and defined by the NOP as a rule, so while these materials may be allowable in the near future, current use of biodegradable plastic mulch in U.S. certified organic production remains prohibited.

Glossary of Key Terms

Abiotic Oxidation - nonliving substances or environmental factors combined with oxygen to cause a loss of electrons.

Aldehydes - Compounds RC(=O)H , in which a carbonyl group (a functional group composed of a carbon atom double-bonded to an oxygen atom) is bonded to one hydrogen atom and to one R group or side chain (IUPAC, 1997).

Biodegradable plastic - Degradable plastic in which the degradation results from the action of naturally occurring microorganisms such as bacteria, fungi, and algae (ASTM, 2011; 2004).

Bio-based - Commercial or industrial products (other than food or feed) that are composed in whole or in significant part of biological products or renewable domestic agricultural materials (including plant, animal, and marine materials) or forestry materials (Biobased US, 2007).

Bioplastics - Form of plastics derived from renewable biomass sources, such as vegetable fats, oils or starches.

Bond scission - breakage of a chemical bond, especially one in a long chain molecule (Oxford Dictionary, 2013).

Deterioration - To weaken or disintegrate.

Degradation -  the breakdown of an organic compound.

Feedstock - Raw material that is used to supply or fuel a process.

Fermentation - The process in which cells (microorganisms, plant or animal cells) are cultured in a bioreactor in liquid or solid medium to convert organic substances into biomass (growth) or into products (IUPAC, 1997).

Genetically Modified Organism (GMO) - An organism whose genetic material has been altered using genetic engineering techniques; also referred to as a genetically engineered organism (GEO).

Inert - Stable and unreactive under specified conditions (IUPAC, 1997).

Ketones - Compounds in which a carbonyl group (a functional group composed of a carbon atom double-bonded to an oxygen atom) is bonded to two carbon atoms. (IUPAC, 1997).

Microbial biomass - Material produced by the growth of microorganisms (IUPAC, 1997).

Mineralization - Microbial conversion of organic matter into inorganic substances, such as water and carbon dioxide (Guggenberger, 2005).

PHA - Polyhydroxyalkanoates (PHAs) are a group of biologically synthesized polyesters that are considered promising eco-efficient bioplastics because they are both biobased and biodegradable, thus meeting the criteria of a closed loop life cycle (Reis et al., 2011).

PLA - polylactic acid (PLA) is a thermoplastic polymer made from lactic acid and has mainly been used for biodegradable products, such as plastic bags and planting cups, but in principle PLA can also be used as a matrix material in composites (Oksman et al., 2003).

Polyethylene - a polymer of ethylene; especially: any of various partially crystalline lightweight thermoplastics (CH2CH2)x that are resistant to chemicals and moisture.

Polymer - A molecule of high relative molecular mass, the structure of which essentially comprises the multiple repetition of units derived, actually or conceptually, from molecules of low relative molecular mass (IUPAC, 1997).

Polymerization - Any process in which relatively small molecules, called monomers, combine chemically to produce a very large chainlike or network molecule, called a polymer (Encyclopedia Britannica 2012).

Synthetic material (according to the USDA NOSB) - A substance that is formulated or manufactured by a chemical process or by a process that chemically changes a substance extracted from naturally occurring plant, animal, or mineral sources, except that such term shall not apply to substances created by naturally occurring biological processes (Sullivan, 2011).

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This is an eOrganic article and was reviewed for compliance with National Organic Program regulations by members of the eOrganic community. Always check with your organic certification agency before adopting new practices or using new materials. For more information, refer to eOrganic's articles on organic certification.

eOrganic 8260

Direct Marketing Channels & Strategy for Organic Products

New/updated @ eXtension - Tue, 06/04/2019 - 16:04

eOrganic author:

Garry Stephenson, Oregon State University

Farmers approach direct marketing in a variety of ways using single or multiple channels. The goal generally is to develop a strategy to sell all the product they produce. This can be through one marketing channel or several. Farms may also add additional direct market channels as the business grows. For instance, many farmers begin with selling through a farmers’ market or a roadside stand. As the business grows they can add other direct channels such as a CSA, grocery or restaurant sales. Direct sales channels for specific crops or a segment of a crop may be combined with wholesale channels. The options are nearly endless.

Eastbank Farmers' Market Portland, Oregon

Farmers' market in Portland, Oregon. Photo credit: Garry Stephenson, Oregon State University

There are many approaches to farm direct marketing. Some have been around for decades others are have been developed more recently. The most common types of direct marketing are:

Community Supported Agriculture—CSA

Community supported agriculture is a relatively recent and innovative concept that is intended to create a relationship between farmers and consumers wherein risks and bounties are shared. CSA customers buy shares for a season by paying a fee in advance. In return, they receive a regular (in most cases weekly) selection of food. Having cash in advance of the growing season and a regular customer following provide financial security for farmers. The regular supply of food grown on the farm provide nutritional security and a sense of community for customers. On some farms, get-togethers with customers or workdays are part of the agreement. In its purest form, customers share in the risk of low production and crop failures, as well as any abundance, by receiving less or more food. This aspect has seen a variety of adaptations on CSA farms.

Generally, families pay about $400 to $600 per share. Operating a CSA requires excellent crop management skills to provide attractive and diverse weekly food baskets, as well as good customer service. CSA can be integrated with farmers’ market sales and other techniques. It has been an excellent start-up strategy for many small organic farms, providing crucial cash flow at the beginning of the growing season and allowing farmers to “boot strap” their way into farming.

CSA Resources Farmers’ Markets

A farmers’ market is a place where a number of growers assemble on a particular day to sell farm products directly to consumers. The sites are often parking lots, streets closed during the market, parks, etc. Farmers at these markets sell their products from “stands” that may consist of the back of a farm truck or a simple tabletop to elaborate and attractive covered displays.

Farmers generally receive retail prices or higher for their products. Start up costs for becoming involved in a farmers’ market can be very inexpensive—just a stall fee in some instances. Because of the low start up investment, farmers’ markets can provide a low risk setting for new farmers or an opportunity to try out new products. Many farmers participate in more than one market to increase their sales.

Farmers’ markets also provide the opportunity to build a customer base. Some farms advertise other outlets for buying their products (other farm direct marketing methods, or retail stores for instance).

Farmers’ Market Resources
  • Tools for rapid market assessments. L. Lev, L. Brewer, and G. Stephenson. 2008. Oregon State University Extension Service. (Available at: http://smallfarms.oregonstate.edu/sites/default/files/small-farms-tech-report/eesc_1088-e.pdf) (verified 5 Mar 2010).
    Most farmers’ markets lack information to make effective changes and improvements. This publication by Larry Lev, Linda Brewer, and Garry Stephenson of Oregon State University describes three simple, low-cost methods to address the information gaps: attendance counts, dot surveys, and comments and observations.
  • Starting and operating a farmers' market: Frequently asked questions [Online]. B. McKelvey, M.Hendrickson, and C. Weber. 2008. University of Missouri Extension.
    Available at: http://extension.missouri.edu/explore/agguides/hort/g06223.htm (verified 5 Mar 2010).
    From University of Missouri Extension, this guide is intended to be a resource for people who are either starting a new farmers' market or improving an existing market. The guide follows a frequently asked questions format, provides brief answers to each question and then directs readers to free, online publications that answer the questions in more detail. In addition to addressing questions faced by market organizers across the country, the guide includes information about legal and regulatory issues for farmers' market organizers in Missouri.
  • The art and science of farmers’ market display [Slide show]. Entrepreneurs and Their Communities Community of Practice. eXtension. Available at:http://www.extension.org/pages/10986/the-art-and-science-of-farmers-market-display#.U87YRBD5eTQ  (verified 5 Mar 2010).
  • Enhancing the success of northwest farmers’ markets. G. Stephenson, L. Lev, and L. Brewer. 2006. Oregon Small Farm Technical Report Number 22. Oregon State University Extension Service. Available at: http://smallfarms.oregonstate.edu/sites/default/files/TechReport22.pdf (verified 5 Mar 2010).
    This executive summary of a large project examines the conditions associated with success and failure of individual farmers’ markets and provides information and recommendations for market organizers to assist with their decision making and strategic planning. It explores historic trends related to growth and decline in market numbers; it examines the management organization associated with markets of specific sizes; it looks at the characteristics and issues associated with markets that fail; and it synthesizes a model that illustrates how farmers’ market organizers successfully adapt to barriers and challenges in their environment.
U-Pick Farms

U-Pick or Pick-Your-Own farms grow crops specifically to be harvested by customers. In this manner, the task of picking the crop, one of the higher costs of growing fruits and vegetables, is passed on to customers. U-Pick farms have traditionally appealed to families who do home canning. There continues to be an interest by families in picking produce for fresh use and, in some instances, having their children experience where their food comes from. As with many direct marketing techniques, U-Pick operations can be blended with other marketing techniques such as roadside markets, farmers’ markets, and so on.

Farm Stands

Farm stands or markets are structures of some type from which the farm’s products are sold. They can range in sophistication from a stand with a coffee can for purchases by honor system to a building with refrigerated storage and several employees. They tend to be located on the farm, often on a well-traveled road with good access and parking. They can operate seasonally or all year and focus on one product or a full line of products. Roadside markets usually charge near retail prices. Given that farm stands or markets are structures, they are subject to local building codes and highway setback regulations.

Restaurants

Many farms are now marketing directly to restaurants providing the specific products and the high quality that chefs are demanding. Many restaurants cultivate relationships with farms even noting the farm name and its product on their menu. These restaurants serve a niche of customers who find high quality food produced locally appealing. Supporting local farms is a philosophical goal for these restaurants.

Similar opportunities for farm direct sales are to institutions that serve food to large or “captive” groups such as:

  • Hospitals
  • Retirement and nursing facilities
  • More
Restaurant Marketing Resources
  • Selling to restaurants. J. Bachmann. 2004. National Center for Appropriate Technology (ATTRA). Available at: https://attra.ncat.org/attra-pub/download.php?id=266 (verified 24 May 2019).
    "Upscale restaurants serving locally-grown produce are in the headlines nationwide. Growing for this market is both lucrative and demanding. Profiles of growers from around the country illustrate successful strategies and points to remember when working with chefs. A Spanish language version of this publication is available as Nuevos Mercados para Su Cosecha."
Recommendations for Farmers and Chefs who Want to Work Together

The Local Food Connection and Farmer-Chef Connection are programs that bring farmers and chefs together for a day of networking and deal making. Read Notes to a Farmer and a Chef to learn how farmers and chefs can best work with each other. The Farmer-Chef Connection is a project of the Portland Chefs Collaborative and the Local Food Connection is a project of the Cascade Pacific RC&D.

Tip Sheets

Selling directly to restaurants, retailers and institutions can be a great way to expand your business and develop a reliable customer base. Created by Community Involved in Sustaining Agriculture (CISA), these tipsheets are designed to help farmers respond to the unique challenges in reaching out to and maintaining relationships with buyers.

Farm to School and Institutions Resources
  • Bring local food to local institutions: A resource guide for farm-to-school and farm-to-institution programs. B.C. Bellows, R. Dufour, and J. Bachmann. 2003. National Center for Appropriate Technology (ATTRA). Available at: https://attra.ncat.org/attra-pub/download.php?id=261 (verified 4 Jun 2019).
    This provides farmers, school administrators, and institutional food-service planners with contact information and descriptions of existing programs that have made connections between local farmers and local school lunchrooms, college dining halls, or cafeterias in other institutions. To help communities initiate similar programs, this publication includes: resource lists of publications on how to initiate and manage local food programs, funding and technical assistance sources, and provisions of the 2002 Farm Bill that support farm-to-school and other community food programs.
  • Farm to school. Urban and Environmental Policy Institute, Occidental College. Available at: http://www.farmtoschool.org/ (verified 5 Mar 2010).
    "Farm to School programs are popping up all over the U.S. These programs connect schools with local farms with the objectives of serving healthy meals in school cafeterias, improving student nutrition, providing health and nutrition education opportunities that will last a lifetime, and supporting local small farmers."
  • Sustainable food purchasing guide, first ed. Yale Sustainable Food Project. Yale University. Available at: http://www.yale.edu/sustainablefood/purchasing_guide_002.pdf.pdf (verified 5 Mar 2010).
    "In 2007, the Yale Sustainable Food Project received a SARE grant to write an expanded set of definitions for dining halls to use across the northeast. Unlike other guides, this one focuses on agricultural practices, because these practices are inseparable from nutrition and sustainability. This guide establishes best and worst practices in the field. It provides a list of questions you need to ask to get the very best product for your institution. It also offers helpful hints, so that you can learn from work that has been done."
  • Rethinking school lunch guide | Center for Ecoliteracy. Center for Ecoliteracy. Available at: http://www.ecoliteracy.org/programs/rsl-guide.html (verified 5 Mar 2010).
    "The Rethinking School Lunch guide provides a planning framework that contains tools and creative solutions to the challenges of improving school lunch programs, academic performance, ecological knowledge, and the well-being of our children. In its chapters, experts and practitioners highlight goals and challenges, showcase success stories, and offer resources for further exploration."
  • Farm-to-cafeteria connections: Marketing opportunities for small farms in Washington state. K. Sanger and L. Zenz. 2004. Small Farm and Direct Marketing Program, Washington State Department of Agriculture. Available at: http://agr.wa.gov/Marketing/SmallFarm/docs/102-FarmToCafeteriaConnection... (verified 5 Mar 2010).
    An extensive resource guide for those interested in starting farm-to-cafeteria programs at all levels, with information for food services, farmers and others. Includes case studies of programs and a list of resources.
  • Farm-to-college. Community Food Security Coalition. Available at: http://farmtocollege.org/ (verified 5 Mar 2010).
    "Farm-to-college programs connect colleges and universities with producers in their area to provide local farm products for meals and special events on campus. These programs may be small and unofficial, mainly involving special dinners or other events, or they may be large and well-established, with many local products incorporated into cafeteria meals every day."
  • Farm to hospital: Supporting local agriculture and improving health care. Center for Food & Justice, a division of the Urban & Environmental
    Policy Institute at Occidental College. Available at: http://www.foodsecurity.org/F2H_Brochure.pdf (verified 5 Mar 2010).
    "This brochure introduces interested farmers and hospital food service departments to the ins and outs of developing partnerships between hospitals and local farms. Included are examples of ways hospitals can improve the food they offer, issues for farmers to consider if they are interested in selling products to area hospitals, and specific case studies of successful programs."
Agritourism

Agritourism appeals to customers who have a desire to visit a farm and experience its activities. As Americans lose family ties with agriculture, many are interested in maintaining some sort of contact with farming; especially for their children. This is a theme with most types of direct marketing but is a key feature of agritourism. There are a variety of approaches.

On-farm bed and breakfasts allow overnight stays to relax in a bucolic atmosphere or, in some instances, work on the farm. The concept of “farm stays,” popular in Europe, is catching on in the U.S. Hay rides to gather Halloween pumpkins or Christmas trees and other family-oriented activities are popular on farms. Other activities such as cattle drives attract customers who are willing to pay to experience a celebrated part of our past and present. Agritourism and entertainment techniques can work in both urbanized areas and very rural areas. As with many direct marketing techniques, people skills are crucial.

Online Marketing

The internet provides a convenient method to advertise the farm business, sell products, and communicate with customers. Most households have access to the internet in their homes. This is a potentially large market for specialty farm products.

Farms may advertise on the internet by developing their own web sites or by participating in web-based farm directories. Farm homepages are an effective means for informing customers of products the farm grows, when they are available, and how to obtain them. Related blogs report on-farm or family activities. A farm may offer details on its CSA or identify which farmers’ markets it sells at. These types of web pages allow customers to see the farm and the people who work there. This enhances the personal aspect of farm direct marketing that many people find appealing. There are also opportunities for sales via the internet. Value-added or even fresh food products may be shipped to customers throughout the country. The internet is a quick and easy method for communicating with established customers. The latest information on product availability, farm news, and other information may be distributed to customers through an email list.

Online Marketing Tip Sheets

Looking to create or improve your online marketing? Download one of these four tip sheets for pointers and guidance. They're full of useful tips and real-life experiences from local farmers. This series was created by Community Involved in Sustaining Agriculture (CISA).

 

This is an eOrganic article and was reviewed for compliance with National Organic Program regulations by members of the eOrganic community. Always check with your organic certification agency before adopting new practices or using new materials. For more information, refer to eOrganic's articles on organic certification.

eOrganic 1493

Records Needed for Organic Poultry Certification

New/updated @ eXtension - Tue, 06/04/2019 - 15:42

eOrganic authors:

Devon Patillo, CCOF

Dr. Jacquie Jacob Ph.D., University of Kentucky

Introduction

Organic poultry producers are required to keep records to demonstrate compliance with USDA National Organic Program (NOP) requirements. Depending on the scale of operation and the method by which eggs, meat, or live birds are sold, certain records may be more appropriate than others.

Organic certification requirements allow recordkeeping systems to be adapted to a particular operation. However, all operations must keep records in enough detail to demonstrate to organic inspectors and certifiers that all requirements of the organic regulations are met. Recommended records are described below. Your certifier will determine your compliance with National Organic Program standards. Be prepared to work with your certifier and adjust your recordkeeping system to meet the required standards.

Poultry producers must meet the organic regulations summarized below. To read the full text of the organic regulations, visit The Electronic Code of Federal Regulations (e-CFR).

 

§ 205.103 Recordkeeping by certified operations

Below is the full text of the recordkeeping requirement of the National Organic Program.

(a) A certified operation must maintain records concerning the production, harvesting, and handling of agricultural products that are or that are intended to be sold, labeled, or represented as “100 percent organic,” “organic,” or “made with organic (specified ingredients or food group(s)).”

(b) Such records must:

(1) Be adapted to the particular business that the certified operation is conducting;

(2) Fully disclose all activities and transactions of the certified operation in sufficient detail as to be readily understood and audited;

(3) Be maintained for not less than 5 years beyond their creation; and

(4) Be sufficient to demonstrate compliance with the Act and the regulations in this part.

(c) The certified operation must make such records available for inspection and copying during normal business hours by authorized representatives of the Secretary, the applicable State program's governing State official, and the certifying agent.

 

§ 205.236: Animal Origin

Section 205.236(c) requires that, “the producer of an organic livestock operation must maintain records sufficient to preserve the identity of all organically managed animals and edible and non-edible animal products produced on the operation.”

  • Animal purchase records
    Birds must be managed organically starting no later than the second day of life.  Keep records to show: date(s) of purchase, number of birds purchased, and the age of animals at time of purchase.
  • Mortality and cull records
    These records ensure that non-organic birds are not added to your flock. Document observed deaths and intentional culls. Bird deaths and culls subtracted from the number of purchased birds need to correspond to the number of birds being certified. Your certifier may use this information to list the number of birds on your certificate and to ensure that non-organic birds have not been added to your flock. (Purchases – Mortality & Culls = Size of current flock)

This means that all organic poultry must be grouped in flocks or otherwise identified, with corresponding records maintained of all feeds and feed supplements purchased and consumed for all stages of life; all health events and medications or activities; housing and pasture rotations; etc. Records must also be maintained of all products produced, including meat and eggs, or feathers for organic fishing flies.

§ 205.237: Feed
  • Feed Production or Purchase Records
    All feed provided must be certified organic. Feed production and/or purchase records need to demonstrate that all feed provided was certified organic. Keep copies of all purchase documentation. Ensure that the total number of pounds purchased is easy to determine. Feed and feed supplement records should include type of feed purchased, quantity purchased, dates purchased, source, and agency that certified the feed as organic. If mixing your own feed, you need to document the same information for each feed ingredient used. You need to list all supplements, including vitamins, amino acids, minerals, etc. used and the reason they were used.
  • Feed labels, ingredient statements, and certification information
    Keep documentation to demonstrate that the feed you purchased was in fact organic. Keep retail labels that include a “Certified Organic by [certifier’s name]” statement. These will appear under the manufacturer’s name on the retail label. If purchasing bulk feed without a retail label, you will need to obtain a list of ingredients in the feed formula and a copy of the manufacturer’s organic certificate, in addition to the purchase invoice and delivery ticket.
  • Feed supplement and additive purchases
    Only approved feed supplements and additives are allowed. Seek approval of feed supplements prior to use. Once approved, keep documentation of your purchases. Ensure the purchase records include the name of the product(s) purchased, quantity purchased, and date.  
§ 205.238: Health care and treatment
  • Health care product purchases (medicines, vaccines, drugs)
    Only approved health care materials are allowed. Seek approval of any health care materials prior to use. Once approved, keep documentation of your purchases. Ensure the purchase records include the name of the product(s) purchased, quantity purchased, and date.
  • Mortality/cull records
    These records provide an indication of the health of your birds. Document observed deaths and intentional culls. If documented on a calendar, be sure to transfer the information from your calendar to a single location before your inspection so it will be easier to see trends or patterns.

A preventive health care program should include control of possible disease vectors including rodents, insects (e.g., external parasites, flies and darkling beetles), and internal parasites. The methods of control should be outlined with a record of monitoring and action(s) taken. Predator control measures should also be documented.

A preventive health care program also includes keeping equipment used clean as well as cleaning and disinfecting between flocks. A record must be kept of all sanitation and cleaning products used and when. Use of any vaccines must be recorded with the date used and source of the vaccine.

Any physical alterations used such as beak trimming, de-snooding, toe trimming, and wing trimming must be recorded with explanation of when performed and why.

As part of your biosecurity program you should limit visitors to your farm. If there are visitors, you should document who and when, and where they had been prior to the visit.

§ 205.239: Living conditions
  • General information
    Certifiers may require specific data about living conditions provided to birds. It is a good idea to have the following information available for your certifier. It is recommended to note the following information on a drawing of any coops or houses:
    • Perch space (inches per bird)
    • Stocking density: Space per bird indoors (square feet per bird)
    • Stocking density: Space per bird outdoors (square feet per bird)
    • Number of birds per nest box (birds per nest box)

Organic poultry are required to have outdoor access depending on their stage of life. The outdoor access area must also be maintained as organic and records kept to document that it has been. This includes a history of how the fields have been used. Section 205.203 requires that all organic producers must take steps to prevent the contamination of water and minimize soil erosion. Soil and water tests should be done to monitor quality. For pastures this will also include the type and source of seeds used. It is also important to document at which age chicks are first given access to the outdoors.

§ 205.105: Other substances
  • Cleaning/Disinfecting records
    Only approved sanitizers are allowed when cleaning houses or facilities between flocks. Some sanitizers must be rinsed, while others do not require a rinse. Work with your certifier to determine sanitizers that are allowed. Document cleaning of houses and include date, sanitizer(s) used, and any other information required by your certifier.
Additional Documentation

As with any commercial operation, the number of eggs or birds produced should be recorded. This documentation is required for organic certification, but also gives the producer an idea of the level of production and early detection of any sudden drops. Daily feed consumption and water intake should also be monitored.

If non-organic products are being raised on the same farm, there must be documentation showing how the commingling of organic and non-organic products is prevented.

The type and amount of bedding material used (e.g., pine shavings) needs to be documented. If bedding materials are consumed by the birds, then the bedding materials must be organic, and records must be maintained to verify organic status.

Manure management is an important part of an integrated farming operation. Manure is a valuable byproduct of poultry production operations and a good source of nutrients for organic crop production. The amount of manure produced, and how it is used, needs to be documented.

Whether you are producing poultry meat or eggs, the products must be handled organically while being shipped for processing. For meat birds, this includes the certification of the facility where the birds are slaughtered, as well as the method and condition of transport to the slaughter facility. The slaughter facility must be certified organic, and its current certificate and documentation must be kept in your records. Similarly, if there is off-farm egg processing, the facility must be certified organic or covered under your certificate in order for the eggs to be labeled as such. If you are processing and packaging the eggs on-farm, the egg handling area and any materials used must be included in the overall organic plan for the farm.

Adapt your recordkeeping system to your own operation

Different producers may need to keep different types of records to demonstrate compliance because of their activities or scale. While certain records are essential for most operations—such as feed purchase records—certifiers may require other records for some producers and not others if they feel that additional information is required to determine compliance with the regulations. In general, larger operations are required to keep more records than smaller operations. Again, your certifier will determine your compliance with National Organic Program standards. Be prepared to work with your certifier and adjust your recordkeeping system to meet the recordkeeping standards.

The records you are required to keep may also depend on how you market your eggs, live organic birds, or meat. If you sell on a wholesale basis to a single buyer, a summary of sales or transportation of birds may be adequate. Total income will also need to be reported. Certifiers rely on this information to ensure that non-organic product is not being sold as organic.

Producers marketing directly to consumers or to a variety of accounts are also required to document total sales. Sales information must include both the quantity of product sold and income from sales. Certifiers rely on this information to ensure that non-organic product is not being sold as organic.

You are required to make your records available during normal business hours to your certifier, state organic program (California only), and authorized representatives of the USDA. You are also required to keep your records on file for no less than five years.

How records might vary for large vesus small producers Large producers
  • Outdoor Access Logs
    Identify dates and reason(s) for confinement. Be specific. Most certifiers will require that you record animals' outdoor access on a daily basis. Additionally, a stated policy or standard operating procedure should describe any time periods when birds are typically confined, including the reason for such confinement (e.g. pullets until feathered).
  • Facility records
    • Diagram of each house
    • Length and width of building
    • Location and size of all doors
    • Outdoor access areas, to scale
    • Locations of feeders/waterers (indoors and outdoors)
    • Temperature logs
    • Cleaning/disinfection of houses between flocks
    • Ammonia levels
Small producers (all birds outside more often than not)
  • Outdoor Access Logs
    Document dates and reason(s) for confinement. Marking days on calendar, with the reason for confinement noted, will most likely be adequate to demonstrate compliance.
  • Bird movement or location records (optional)
    Small producers that move birds around pasture may wish to record the days when birds are moved. This can provide assurances to certifiers that the ground on which birds trod does not become contaminated by excess manure.
References and Citations

This is an eOrganic article and was reviewed for compliance with National Organic Program regulations by members of the eOrganic community. Always check with your organic certification agency before adopting new practices or using new materials. For more information, refer to eOrganic's articles on organic certification.

eOrganic 7778

Twelve Steps Toward Ecological Weed Management in Organic Vegetables

New/updated @ eXtension - Tue, 06/04/2019 - 15:12

eOrganic author:

Mark Schonbeck, Virginia Association for Biological Farming

Introduction

Ecological weed management begins with careful planning of the cropping system to minimize weed problems, and seeks to utilize biological and ecological processes in the field and throughout the farm ecosystem to give crops the advantage over weeds. In addition, mechanical and other control measures are usually needed to protect organic crops from the adverse effects of weeds. This is particularly true in vegetables and other annual crops, for which production practices keep natural plant succession at its earliest stages, thereby eliciting the emergence of pioneer plants that can become agricultural weeds.

While tillage and cultivation can degrade soil quality and increase the risk of erosion losses, many other organic weed management tools (Table 1) are more soil-friendly. For example, a diversified rotation of vigorous cash crops and cover crops can enhance soil organic matter, tilth, and fertility, provided that a sufficient quantity and diversity of residues are returned to the soil to feed the soil life. Grazing livestock after a production crop to remove weeds or interdict weed seed set can add fertility in the form of manure, though intensive grazing can also compact the soil. In the interest of food safety, care must be taken to avoid direct contact of fresh manure with vegetables and other food crop. Mowing and flame weeding (if properly done to avoid excessive heating of the soil itself) are much easier on soil structure than cultivation, and can be just as effective in certain stages of weed and crop development. Mowing or rolling a cover crop to form an in situ mulch can enhance the soil benefits of the cover crop, compared to tilling it in, and can effectively suppress many annual weeds. Other organic mulches, such as straw and chipped brush, add organic matter, whereas synthetic clear or colored plastic films and weed barrier fabrics do not. All mulches are very effective in preventing soil erosion.

 

Table 1. A summary of organic weed management tools.   Preventive Control Major tools:     The Grower’s Mind (planning, observation, and ingenuity) X X Vigorous Cash Crops X   Crop Rotation X   Cover Crops X   Organic Mulches X X Opaque Synthetic Mulches (black plastic, etc.) X X Conservation Biological Control (conserve weed consumers present on farm) X X Livestock X X Tillage and Cultivation Tools and Implements   X Mowers and other Cutting Tools   X Rollers and Roll-crimpers (for converting mature cover crops into in-situ mulch) X X Flame Weeders   X Minor and experimental tools:     OMRI certified organic herbicides   X Bioherbicides (specific pathogens of weeds)   X Management of soil microflora X X Specific crop–weed allelopathic interactions X X Classical biological controls for specific weeds (usually against invasive exotic weeds in rangeland and natural ecosystems)   X Clear plastic mulch (soil solarization) X X

 

Ecological weed management consists of many-component strategies tailored to each region, cropping system, and farm. Matt Liebman and Eric Gallandt (1997) describe the process as using “many little hammers”, including “indirect controls”, such as crop variety, planting date, and nutrient management, rather than relying only on the “direct controls” or “large hammers” of cultivation and herbicides. In their words, “the use of a combination of methods can lead to (i) acceptable control through the additive, synergistic, or cumulative action of tactics that may not be effective when used alone, (ii) reduced risk of crop failure or serious loss by spreading the burden of protection across several methods, and (iii) minimal exposure to any one tactic, and consequently reduced rates at which pests adapt and become resistant.” (Liebman & Gallandt, 1997, p. 326)

The following list outlines twelve key steps toward successful organic weed management that are discussed in greater detail in a series of related articles that can be found on this website. Note that these steps do not comprise a precise linear sequence of instructions; rather they offer a conceptual framework within which each farmer can develop a site-specific strategy. This process requires systems thinking, which views the field as a complex system of interacting components—such ascrops, weeds, soil, insects, and microorganisms—that form a web of relationships, not a linear sequence of cause-and-effect. Similarly, the following steps are employed together in a synergistic manner, and thus differ from the sequence of instructions for assembling a car or a farm implement. For example, Step 6 (cover crops) can be seen as a part of Step 2 (minimize niches for weeds), and Step 1 (know the weeds) provides vital information for other steps, particularly steps 3 (keep the weeds guessing), 4 (design for effective weed control), and 7 (manage the weed seed bank). Biological processes (Step 9) include indigenous biocontrols that help reduce the weed seed bank (Step 7) as well as the competitive and allelopathic effects of cover crops (Step 6). Step 11 (observe weeds and adapt practices) is an ongoing feedback loop that informs and fine-tunes all the other steps. Utilizing this or another suitable framework, the organic grower selects and assembles a set of “many little hammers” that, working together, keep the farm’s weeds from becoming major weed problems.

Planning Steps

1. Know the Weeds Obtain correct identification of the major weeds present on the farm. Monitor fields regularly throughout the season. Keep records on what weeds emerge at different seasons, and on efficacy of any preventive and control measures taken. Learn each weed’s life cycle, growth habit, seasonal pattern of development and flowering, modes of reproduction and dispersal, seed dormancy and germination, and how the weed affects crop production. Find the weed’s weak points—possibly the stages in its life cycle that are most vulnerable to control tactics—and stresses to which the weed is sensitive; these can be exploited in designing a management strategy.

"Know the weeds" is listed first because it informs most of the succeeding steps. However, gaining a thorough knowledge of the farm’s weed flora is an ongoing process over many seasons (perhaps the lifetime of the farmer!) that drives the year-to-year refinement of the farm’s weed management system.

2. Design the Cropping System to Minimize Niches for Weed Growth In planning the crop rotation, avoid creating open niches in time or space. Plan tight rotations that follow one crop harvest promptly with the next planting. Open niches in space between crop rows can be reduced by using a narrower row spacing, intercropping, relay cropping, overseeding cover crops into established vegetables, or no-till management of cover crops prior to transplanting vegetables.

3. Keep the Weeds Guessing with Crop Rotations Plan and implement diversified crop rotations that vary timing, depth, frequency, and methods of tillage; timing and methods of planting, cultivation, and harvest; as well as crop plant family. Alternate warm- and cool-season vegetables. Rotate vegetable fields into perennial cover for two or three years to interrupt life cycles of annual weeds adapted to frequent tillage. Schedule tillage and cultivation operations when they will do the most damage to the major weed species.

4. Design the Cropping System and Select Tools for Effective Weed Control Develop control strategies to address anticipated weed pressures in each of the farm’s major crops. Choose the best cultivation implements and other tools for cost-effective preplant, between-row, and within-row weed removal. Plan bed layout, as well as row- and plant spacing, to facilitate precision cultivation. Choose irrigation methods and other cultural practices that are compatible with planned weed control operations.

Preventive Steps During the Season

5. Grow Vigorous, Weed-competitive Crops A healthy, fast-growing crop that can outcompete weeds is the best way to prevent weed problems. Choose locally-adapted crop varieties that grow tall or form lots of foliage that can shade out weeds. Maintain healthy, living soil. Provide optimum growing conditions—planting date and spacing, moisture, soil tilth and aeration, fertility, and pest and disease management. Deliver water and fertilizer within-row to feed the crop and not the weeds. Note that either insufficient or excessive levels of major nutrients (nitrogen, phosphorus, and potassium) can give certain weeds a competitive advantage over the crops.

6. Put the Weeds Out of Work—Grow Cover Crops! Cover crops do the same job as weeds, only better. They rapidly occupy open niches, protect and restore the soil, provide beneficial habitat, add organic matter, and hold and recycle soil nutrients. They suppress weeds through direct competition and sometimes through allelopathy—the release of plant-growth-inhibiting substances into the soil. Whenever a bed or field becomes vacant, plant a cover crop immediately so that it can begin the vital restorative work that nature accomplishes with pioneer plants or weeds. Good cover cropping plays a major role in Step 2 (minimzing open niches), and can put the weeds out of a job.

7. Manage the Weed Seed Bank—Minimize “Deposits” and Maximize “Withdrawals” Prevent formation and release of viable weed seeds, and proliferation of rhizomes and other propagules of perennial weeds. Avoid importing new weeds with manure, mulch hay, and other materials from off-farm sources. Utilize stale seedbed, cultivated fallow, or targeted tillage practices to draw down seed banks of the major weeds present. Encourage weed seed mortality and weed seed consumption by ground beetles and other organisms (see Step 9 below).

Control Steps During the Season

8. Knock Out Weeds at Critical Times Plant vegetables into a clean seedbed, hit early-season weeds while the are small, and keep crops clean through their critical weed free period (through the first third or half of the life cycle of most vegetables). Prevent seed set by “escapes” and late season weeds. When practical, interrupt vegetative propagation by invasive perennial weeds through timely removal of top growth.

9. Utilize Biological Control Processes to Further Reduce Weed Pressure Rotate livestock, poultry, or weeder geese through fields to graze weeds and interrupt seed set. To ensure food safety and comply with USDA Organic Standards, time such grazing so that fresh droppings are not deposited any less than 120 days prior to harvest of the next crop. Encourage weed seed predation and decay by maintaining high soil biological activity and providing habitat (mulch, cover crops, hedgerows) for belowground and aboveground weed seed consumers (conservation biological control). Enhance overall soil biological activity to tip the competitive balance in favor of crops, and possibly to shorten the "half life" of the weed seed bank.

Classical biological controls (introduced natural enemies) are commercially available for a few invasive exotic weeds.

10. Bring Existing Weeds Under Control Before Planting Weed-sensitive Crops Weed control in perennial horticultural crops like asparagus, small fruit, and some cut flowers can be quite difficult, especially when perennial weeds dominate the weed flora. Bring existing weed pressures under good control through repeated tillage and intensive cover cropping before planting any perennial vegetable, fruit, or ornamental crops. Choose fields with the best weed control or lowest weed pressure for weed-sensitive annual vegetables with a long critical weed free period, such as carrot, onion ,and parsnip. Be sure weeds, especially perennial weeds, are under good control before attempting no-till management of cover crops prior to cash crop planting.

Enhancing the Organic Weed Management System – Observe, Adapt, Experiment

11. Keep Observing the Weeds and Adapt Practices Accordingly Note and record any changes in weed species composition, emergence and growth pattern, or weed pressure, and modify practices as needed. For example, an increase in certain annual “weeds of cultivation” may indicate a need to reduce tillage or diversify the crop rotation. An increase in invasive perennials may require tilling deeper or more aggressively for a time. Watch out for the arrival of new weed species that could pose problems.

Expect weed populations and flora to shift over time. Every farm decision and field operation can elicit changes in the weed community, as can weather variations, to say nothing of long term climate changes. “Reading” the weeds each year becomes an information feedback loop, guiding weed management practices for the following season.

12. Experiment Try out new tactics and strategies to deal with major weed challenges. Farmers continually develop innovative strategies based on new tools that they fashion themselves or that researchers develop, new uses for old tools, and new combinations of preventive and control tactics. In the words of University of Vermont Extension Specialist Vern Grubinger (1997):

Experiment to fine-tune your weed management tactics.

  • Start on a small scale with tools and techniques that are new to your farm.
  • Identify your most problematic weeds and compare different combinations or rotations, cover crops, and cultivation tools to see how effective they are in providing control.
  • Keep an eye out for new tools, or new ways to use old tools.
  • Leave a control row or section untreated, so you can see the effectiveness of your tactics.

~ Grubinger, 1997.

Part of experimenting is to watch for new developments. Researchers and farmers continue to explore and expand the horizons of possibility in ecological and organic weed management. Check farming magazines and publications for practical applications of their work, from new cultivation tools to new strategies for particularly stubborn weed problems. Some cutting edge areas of research may take longer to yield practical results, yet bear watching and possible integration into a farm’s weed management strategy. These range from natural herbicides, bioherbicides, and classical biological controls, to specific weed–crop allelopathic interactions and manipulation of weed–crop–soil–microbe relationships to give the crop a competitive edge over certain weeds.

While none of these endeavors is likely to yield a “big hammer” to replace herbicides or steel, they can contribute additional “little hammers” to enhance efficacy and reduce the amount of tillage and cultivation needed.

Caution: This is Not a Cookbook

An effective organic weed management system cannot be spelled out precisely because ecological weed management is inherently site specific and responsive to changes in the farm ecosystem. There is effectively no “organic weed control cookbook” to replace the precise herbicide protocols that have been developed for conventional production of row crops and some vegetables. No scientist can come up with a better weed management strategy for a particular farm than the strategy a skillful organic farmer can develop by applying ecological weed management principles to the particular suite of crops, weeds, soil conditions, and available resources on her or his farm.

This outline is not the only valid roadmap available. There is nothing set-in-stone about the number of steps or the order in which they appear here. Other outlines for ecological weed management have been developed for particular regions and cropping systems; these may be more directly applicable to your farm or situation. See the References and Additional Resources below for some specific examples.

For more on the ecological approach to managing agricultural weeds, see An Ecological Understanding of Weeds, and Integrated Pest Management Concepts for Weeds in Organic Farming Systems.

 

References and Citations
  • Grubinger, V. 1997. 10 steps toward organic weed control. American Vegetable Grower 46: 22–24.
  • Liebman, M., and E. R. Gallandt. 1997. Many little hammers: ecological approaches for management of crop–weed interactions. p. 291–343. In L. E. Jackson (ed.) Ecology in agriculture. Academic Press, San Diego, CA.
Additional Resources

 

This is an eOrganic article and was reviewed for compliance with National Organic Program regulations by members of the eOrganic community. Always check with your organic certification agency before adopting new practices or using new materials. For more information, refer to eOrganic's articles on organic certification.

eOrganic 2320

Soil Health and Organic Farming Webinar Series

New/updated @ eXtension - Tue, 06/04/2019 - 07:58

The Organic Farming Research Foundation and eOrganic presented a series of 9 webinars focused on soil health topics: building organic matter, weed management, conservation tillage, cover crops, plant breeding and variety selection, water management and quality, nutrient management, and more! This series is recommended for farmers, extension agents, educators, agricultural professionals, and others interested in building soil health. Presenters Mark Schonbeck and Diana Jerkins of the Organic Farming Research Foundation reviewed the most recent research on soil health practices and explored how organic growers can build healthy soils on their operations. The webinars provide practical guidelines for growers and in-depth analysis of research outcomes. Scroll down to view the recordings, slides and accompanying presentation notes. The Organic Farming Research Foundation has also produced a series of Soil Health Guides which cover the topics in these webinars. Download the guides at https://ofrf.org/soil-health-and-organic-farming-ecological-approach.

May 9, 2018: Building Organic Matter for Healthy Soils: An Overview

We will discuss the attributes of healthy soil, the central role of organic matter, and how to monitor and enhance soil health in organic production. The presentation will outline key organic practices for building soil organic matter and optimizing soil functions in relation to fertility, crop yield, and resource conservation.

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Slide handout

June 13, 2018: Weed Management: An Ecological Approach

This webinar will focus on integrated organic weed management tools and practices that give crops the edge over weeds, build soil health, and reduce the need for soil disturbance. Slide handout

September 19, 2018: Practical Conservation Tillage

This webinar includes the impacts of tillage on soil health, including practical, soil-friendly tillage practices for organic systems. We will discuss several newer tillage tools and approaches that reduce adverse impacts on soil life and soil structure.

Slide handout, Presentation notes

October 17, 2018: Cover Crops: Selection and Management

This webinar will focus on selecting the best cover crops, mixes, and management methods for soil health, including crop rotations and cropping system biodiversity.

Slide handout, Presentation notes

November 14, 2018: Plant Genetics: Plant Breeding and Variety Selection

This webinar will cover plant breeding and variety selection for performance in sustainable organic systems, including nutrient and moisture use efficiency, competitiveness toward weeds, and enhanced interactions with beneficial soil biota. We will also discuss heritable traits that could directly benefit soil biology and soil health.

 

 Slide handout Presentation notes

January 9, 2019: Water Management and Water Quality

This webinar will focus on the role of soil health and organic soil management in water conservation and water quality. 

Slide handout, Presentation notes

February 20, 2019: Nutrient Management for Crops, Soil and the Environment

This webinar includes a discussion of the role of soil health and the soil food web, including practical guidelines for optimizing crop nutrition, minimizing adverse environmental impacts of organic fertility inputs, and adapting soil test-based nutrient recommendations (especially N) for organic systems.

Slide handout, Presentation notes

March 20, 2019: Organic Practices for Climate Mitigation, Adaptation, and Carbon Sequestration

In this webinar, we will discuss the capacity of sustainable organic systems and practices to sequester soil carbon, minimize nitrous oxide and methane emissions during crop and livestock production, and enhance agricultural resilience to weather extremes. The presentation will include practical guidelines for optimizing the organic farm’s “carbon footprint” and adaptability to climate disruptions already underway.

Slide handout, Presentation notes

May 22, 2019: Understanding and Managing Soil Biology for Soil Health and Crop Production

This webinar will examine the functions of the soil food web and key components thereof in promoting soil health and fertility and sustainable organic crop production. Research-based guidance on organic practices and NOP-approved inputs for improved soil food web function will be discussed.

Slide handout, Presentation notes

About the Presenters

Mark Schonbeck is a Research Associate at the Organic Farming Research Foundation. He has worked for 31 years as a researcher, consultant, and educator in sustainable and organic agriculture. He has participated in on-farm research into mulching, cover crops, minimum tillage, and nutrient management for organic vegetables. For many years, he has written for the Virginia Association for Biological Farming newsletter and served as their policy liason to the National Sustainable Agriculture Coalition. He has also participated in different research projects to analyze, evaluate and improve federally funded organic and sustainable agriculture programs. In addition, Mark offers individual consulting in soil test interpretation, soil quality and nutrient management, crop rotation, cover cropping, and weed management.

Diana Jerkins is the Research Program Director of the Organic Farming Research Foundation. She has decades of experience in agricultural research, federal program management, university administration and hands-on farming. She was a National Program Leader with the US Department of Agriculture’s National Institute of Food and Agriculture (NIFA) between 2002 and 2014, and she helped implement the agency’s first sustainable and organic agriculture programs. 

Thank you to the Clarence E. Heller Charitable Foundation for supporting this project.

This is an eOrganic article and was reviewed for compliance with National Organic Program regulations by members of the eOrganic community. Always check with your organic certification agency before adopting new practices or using new materials. For more information, refer to eOrganic's articles on organic certification.

eOrganic 25148

Making and Using Compost for Organic Farming

New/updated @ eXtension - Fri, 05/31/2019 - 15:47

eOrganic authors:

Emily Marriott, University of Illinois at Urbana-Champaign

Ed Zaborski, University of Illinois at Urbana-Champaign

Introduction

Composting transforms raw organic residues into humus-like material through the activity of soil microorganisms. Mature compost stores well and is biologically stable, free of unpleasant odors, and easier to handle and less bulky than raw organic wastes. In agronomic and horticultural operations, compost can be used as a soil amendment, seed starter, mulch, container mix ingredient, or natural fertilizer, depending on its characteristics. Composting can also reduce or eliminate weed seeds and plant pathogens in organic residues.

Compost provides many benefits as a soil amendment and a source of organic matter by improving soil biological, chemical, and physical characteristics:

  • Increases microbial activity
  • Enhances plant disease suppression
  • Increases soil fertility
  • Increases cation exchange capacity
  • Improves soil structure in clayey soils
  • Improves water retention in sandy soils
  • Reduces bioavailability of heavy metals
Overview of the Composting Process

Microorganisms drive the composting process, so creating an optimal environment for microbial activity is crucial for successful and efficient composting. Assembling an appropriate mix of organic residues or feedstocks and maintaining adequate moisture and oxygen levels are all necessary.

As soon as feedstocks are compiled, the composting process begins. As microorganisms begin to decompose the organic materials, the compost pile heats up and the active phase of composting begins. During this phase of rapid decomposition, temperatures in the pile increase to 130–150°F and may remain elevated for several weeks. Maintaining adequate aeration during this phase of intense microbial activity is especially important because aerobic decomposition is most efficient and produces finished compost in the shortest amount of time. As readily available organic matter is consumed and decomposition slows, temperatures in the compost pile decrease to around 100°F and the curing phase begins. At this stage, the compost can be stockpiled.

Common methods of on-farm composting include static piles, windrows (elongated piles), and in-vessel (enclosed) composting. Static piles are compost piles that are not turned. To meet National Organic Program requirements, static pile systems must be aerated to sustain microbial activity and adequate temperatures. To that end, perforated pipe is installed at the base of the pile and in some cases fans or blowers are used to force air through the pile.

Static compost piles with passive aeration tubes
Figure 1. Static compost piles with passive aeration tubes. Photo credit: Robert Rynk, Compost Education and Resources for Western Agriculture project, Washington State University.

Windrows, or enlongated piles of compost feedstocks, are turned or mixed regularly to aerate the pile and to reestablish pore space.

Profiles of compost windrows at a dairy in eastern Washington
Figure 2. Profiles of compost windrows at a dairy in eastern Washington. Photo credit: David Granatstein, Compost Education and Resources for Western Agriculture project, Washington State University.

this farm-scale rotating drum is used at a Texas site
Figure 3. An example of in-vessel composting. This farm-scale rotating drum is used at a Texas site. Photo credit: Robert Rynk, Compost Education and Resources for Western Agriculture project, Washington State University.

How to Compost

Several comprehensive resources providing detailed explanations of the composting process and specific information on how to make compost are available; examples include The Art and Science of Composting (Cooperband, 2002a), Composting on Organic Farms (Baldwin and Greenfield, 2009), and On-Farm Composting Handbook (Rynk, 1992).

Large-scale composting is regulated in most states. Check with your state government to ensure compliance with composting regulations.

Compost and the National Organic Program

The use of composted plant and animal materials to maintain or improve soil organic matter is supported by the National Organic Program (NOP) final rule (United States Department of Agriculture [USDA], 2000):

The producer must manage plant and animal materials to maintain or improve soil organic matter content in a manner that does not contribute to contamination of crops, soil, or water by plant nutrients, pathogenic organisms, heavy metals, or residues of prohibited substances.

~ 7 CFR 205.203(c)

The composition, production, and use of compost in organic production systems is regulated by the NOP final rule; the NOP provided clarification of these regulations in guidance on the allowance of green waste in organic production systems (NOP, 2010a) and in draft guidance on compost and vermicompost in organic crop production (NOP, 2010b). In addition, the NOP provided guidance on uncomposted, processed animal manures in organic crop production (NOP, 2010c).

Composition

According to NOP's guidance on the allowance of green waste in organic production systems (NOP, 2010a) and draft guidance on compost and vermicompost in organic crop production (NOP, 2010b), approved feedstocks for compost include:

  • Plant and animal materials, such as, crop residues, animal manure, food waste, yard waste
  • Nonsynthetic substances not prohibited by 7 CFR 205.602
  • Synthetic substances specifically allowed for use as a compost feedstock per 7 CFR 205.601 [only "newspapers or other recycled paper, without glossy or colored inks"]
  • Synthetics approved for use as plant or soil amendments

NOP regulation states that compost that is produced with prohibited feedstocks (urea, recycled wallboard, or sewage sludge, for example) is prohibited, and it does not permit the use of compost that contains synthetic substances that are not on the National List of synthetic substances allowed for use in organic crop production (see Can I Use this Input on My Organic Farm?). However, recognizing that background levels of pesticides are present in the environment (referred to as unavoidable residual environmental contamination—UREC—in the regulations) and may be present in organic production systems, NOP regulation does not mandate zero tolerance for synthetic pesticide residues in inputs, such as compost. According to NOP guidance,

Green waste and green waste compost that is produced from approved feedstocks, such as, non-organic crop residues or lawn clippings may contain pesticide residues. Provided that the green waste and green waste compost (i) is not subject to any direct application or use of prohibited substances (i.e. synthetic pesticides) during the composting process, and (ii) that any residual pesticide levels do not contribute to the contamination of crops, soil or water, the compost is acceptable for use in organic production.

~ NOP, 2010a

What constitutes "contamination of crops, soil or water"? The NOP final rule states (USDA, 2000, 7 CFR 205.671) "When residue testing detects prohibited substances at levels that are greater than 5 percent of the Environmental Protection Agency's tolerance for the specific residue detected or unavoidable residual environmental contamination, the agricultural product must not be sold, labeled, or represented as organically produced." NOP is thus far silent on what constitutes contamination of soil or water.

Compost feedstocks may contain synthetic pesticide contaminants that are not degraded in the composting process, and can contribute to crop, soil, or water contamination. This was the case for the herbicide clopyralid, which was used on turfgrass as well as in agriculture. It passes through animals in the urine, and therefore if they eat forage with clopyralid residues, the herbicide ends up in the bedding and potentially in the compost. Similarly, clopyralid can contaminate compost made from clippings from treated lawns. The uses of this herbicide have been restricted to avoid this problem, but it is advisable to ask the compost vendor or the provider of raw feedstock materials about such potential contaminants. For more information, see the Washington State University Puyallup Research Center publications on clopyralid in compost.

The source of all compost feedstock materials should be known to ensure that they are allowed for use in organic production. Knowing the feeding practices used for manure sources and having the manure tested can also provide information about possible antibiotic and heavy metal contamination. The use of compost containing these contaminants is not permitted in organic crop production; however, the organic rule does not require that manures come from organic livestock farms to be used in organic compost production.

The use of broiler litter as a feedstock for compost production poses some additional concerns. Arsenic is a component of some feed medications or growth promoters used in commercial broiler operations. The majority of arsenic consumed by poultry is excreted and incorporated into the litter, leading to the potential for build-up in the soil and leaching from compost piles into lakes and streams. For more information, consult the ATTRA publication, Arsenic in Poultry Litter: Organic Regulations, by Bellows (2005).

Increasing use of copper in broiler and hog operations may result in manures with high concentrations of copper. Copper foot baths are also common in cattle production. While copper is a necessary plant nutrient, it can become toxic in very high concentrations. Sustained use of compost from these sources could contribute to copper build-up in the soil in the long-term, especially in operations that rely on copper as a pesticide.

Production

The NOP regulations refer to production methods for compost in the context of managing plant and animal materials to maintain and improve soil organic matter content:

The producer must manage plant and animal materials to maintain or improve soil organic matter content in a manner that does not contribute to contamination of crops, soil, or water by plant nutrients, pathogenic organisms, heavy metals, or residues of prohibited substances. Animal and plant materials include:
…
   (2) Composted plant and animal materials produced though a process that:
      (i) Established an initial C:N ratio of between 25:1 and 40:1; and
      (ii) Maintained a temperature of between 131°F and 170°F for 3 days using an in-vessel or static aerated pile system; or
      (iii) Maintained a temperature of between 131°F and 170°F for 15 days using a windrow composting system, during which period, the materials must be turned a minimum of five times.

~ 7 CFR 205.203(c)(2), USDA, 2000

The NOP's draft guidance on compost and vermicompost in organic crop production (NOP, 2010b) identifies these processes as examples of methods for producing acceptable composts, and states that:

An example of another acceptable composting method is when:
   a. Compost is made from allowed feedstock materials (either nonsynthetic substances not
prohibited at §205.602, or synthetics approved for use as plant or soil amendments), and
   b. The compost pile is mixed or managed to ensure that all of the feedstock heats to the minimum of 131°F (55°C) for a minimum of three days. The monitoring of the above parameters must be documented in the Organic System Plan in accordance with §205.203(c) and submitted by the producer and verified during the site visit.

~ NOP, 2010b

NOP compost requirements can also be met by vermicompost (compost produced by the action of earthworms), so long as:

a. It is made from allowed feedstock materials (either nonsynthetic substances not prohibited at §205.602, or synthetics approved for use as plant or soil amendments);
b. Aerobicity is maintained by regular additions of thin layers of organic matter at 1–3 day intervals;
c. Moisture is maintained at 70–90%; and
d. The duration of vermicomposting is at 6–12 months for outdoor windrows, 2–4 months for indoor container systems, 2–4 months for angled wedge systems, or 30–60 days for continuous flow reactors.

~ NOP, 2010b

Compost production practices, including the type and source of all feedstock materials, temperature monitoring logs by date, and practices used to achieve uniform elevated temperatures, should be described in the organic system plan (OSP).

Use

Compost made in accordance with the above production criteria may be applied in organic production systems without restriction on the time interval between application and crop harvest.

Composts that don't meet the above production criteria may still be used in organic farming. However, if they contain animal manure, they must be applied to agricultural land in accordance with NOP regulations for manure, which state that raw animal manure must be composted unless at least one of the following conditions is satisfied:

  • Applied to land used for a crop not intended for human consumption
  • Incorporated into the soil not less than 120 days prior to the harvest of a product whose edible portion has direct contact with the soil surface or soil particles
  • Incorporated into the soil not less than 90 days prior to the harvest of a product whose edible portion does not have direct contact with the soil surface or soil particles

~ 7 CFR 205.203(c)(1), USDA, 2000

Compost Quality

Compost quality varies depending on the raw organic materials (feedstocks), the composting process used, and the state of biological activity. Before using compost as a soil amendment, it is a good idea to evaluate its quality by determining moisture content, organic matter content, C:N ratio, and pH (Table 1).

Table 1. Qualities of compost for on-farm use and how to test (after Cooperband, 2002a). Quality Optimum How to test Source of organic matter Should have a good organic matter content (40-60%) Have organic matter tested by a soil lab Source of nitrogen 10–15:1 C:N ratio Have C:N ratio tested by a soil lab Neutral pH 6–8 Use soil pH kit at home or have pH tested by a soil lab Low soluble salts If compost will be spread in the fall, no test necessary N/A If compost will be spread before planting, levels should be below 10 dS Have soluble salts tested by a soil lab No phytotoxic compounds Good seed germination (>85%) Plant 10 seeds in a small pot Weed-free No or few weed seeds Moisten compost and watch for weed seedling growth Compost and Disease Suppression

Compost can be effective at controlling some soil-borne diseases, particularly root-rot diseases. By providing a favorable environment and food source, compost encourages the growth of microorganisms that compete with, parasitize, or produce natural antibiotics against plant pathogens. Additionally, increased plant vigor due to compost application can increase resistance to plant pathogens. For more information see the chapter on Compost and Disease Suppression in the ATTRA publication Sustainable Management of Soil-Borne Plant Diseases by Sullivan (2004). See a related article to learn how composting can reduce or eliminate weed seeds and plant pathogens in crop residues and other organic feedstocks.

Compost and Soil Fertility

Generally, compost can be considered more as a soil conditioner than as a fertilizer substitute because it improves plant productivity primarily by improving physical and biological soil properties and increasing soil organic matter, rather than by directly supplying significant amounts of plant-available nutrients. By increasing soil organic matter content, which fuels microbial activity and nutrient cycling, compost applications will increase overall soil fertility. Over subsequent growing seasons, the nitrogen applied in compost will become plant-available.

Compost Application Rates

Compost should be considered a slow-release source of nitrogen. Most nitrogen remaining after completion of the composting process is bound into organic forms and thus not available immediately for plant uptake. Compost routinely applied at rates high enough to meet immediate crop N requirements will almost always result in excess P and K application. Excess P can result in surface water pollution (and potentially threaten organic certification). In some cases, excess K can upset crop nutrition balance.

Compost application rates can be calculated using fertilizer recommendations from soil tests, compost nutrient analysis, and methods similar to those used to determine manure application rates. When using this method, nutrient availability in compost must also be taken into account. General guidelines suggest that 10 to 25% of compost N will be plant-available during the first year of application. Estimates for P and K availability in the first year are higher, 40% and 60% respectively. It is important to keep in mind that these are only estimates and actual availability will depend on the nature of the compost and—for N especially—conditions during the growing season that affect N mineralization. Composting on the Organic Farm, by Baldwin and Greenfield (2009), provides detailed instructions for calculating application rates.

This vegetable producer in Washington State built his own compost spreader from existing equipment.
Figure 4. This vegetable producer in Washington State built his own compost spreader from existing equipment. Photo credit: David Granatstein, Compost Education and Resources for Western Agriculture project, Washington State University.

References and Citations Additional Resources

 

This is an eOrganic article and was reviewed for compliance with National Organic Program regulations by members of the eOrganic community. Always check with your organic certification agency before adopting new practices or using new materials. For more information, refer to eOrganic's articles on organic certification.

eOrganic 2880

Legume Inoculation for Organic Farming Systems

New/updated @ eXtension - Fri, 05/31/2019 - 15:25

eOrganic author:

Dr. Julie Grossman, North Carolina State University

What Is Inoculation?

Legumes growing together with soil bacteria called rhizobia work together to take atmospheric nitrogen (N2) found in soil air spaces and transform—or fix—it into a plant-available form through the process called Biological Nitrogen Fixation (BNF) (Fig. 1). Even though the atmosphere is almost 80% N, the N2 gas is such that plants can't use it for their own growth and development unless it is fixed. However, neither legumes nor the rhizobia can do the job alone. The process must occur as part of a mutually beneficial—or symbiotic—relationship with soil-dwelling rhizobia bacteria. Rhizobia form root nodules on the host legume, thereby providing the plant with transformed N in exchange for a portion of the carbohydrates made by the plant.

Figure 1. Biological Nitrogen Fixation provides nitrogen fertility in legume-based cropping systems.
Figure 1. Biological Nitrogen Fixation provides nitrogen fertility in legume-based cropping systems. Figure credit: Nape Mothapo, North Carolina State University.

In order for BNF to occur, certain things need to happen. First, because there are many types of rhizobia, the right type of rhizobia to form nodules with your particular legume must be in contact with the growing legume root. Additionally, the rhizobia must be efficient in fixing atmospheric N, and, of course, they must be alive! The application of the recommended type of bacteria to the seed or soil prior to planting is called inoculation. With so much to take into account to produce a strong healthy legume–rhizobia relationship, successful inoculation can seem daunting. This document will introduce you to legume inoculation and recommend proper inoculation methods for certified organic growers. Readers can view related articles for additional information on general soil fertility in organic farming systems and soil microbial nitrogen cycling in organic farming systems.

Two ways to help provide your grain, forage, or cover crop legume with the N it needs for growth and development are: (1) make sure your legumes are well nodulated, and (2) verify that nodules contain effective rhizobia. The presence of nodules alone does not ensure that N is being actively fixed. Some rhizobia are ineffective, meaning that they can form nodules, but do not fix nitrogen. To check for effective rhizobia and nitrogen fixation in the field, dig out several plants and wash root systems in water to remove soil. Then select 2–3 nodules from each plant and slice them in half. Nodules that have pink or red interiors indicate that the rhizobia are hard at work fixing nitrogen, while greenish or white interiors contain ineffective rhizobia. Inoculation of your seeds prior to planting is one proven way to have the correct type of bacteria present within the vicinity of the legume's growing root.

When is it Necessary to Inoculate? Species specificity and cross inoculation groups

Figure 2. Well-formed nodules on the root system of a vetch plant.
Figure 2. Well-formed nodules on the root system of a vetch plant. Photo credit: Julie Grossman, North Carolina State University.

Rhizobia bacteria are picky little critters and are fairly specific about which legume species they will select as a host to form nodules. It is important that you purchase the correct type of bacteria for your legume seed. Some species of rhizobia can infect more than one species of legume. For example, peas and vetch all form nodules with the rhizobia species Rhizobium leguminosarum, while true clovers are all infected by R. trifolii. The groups of legumes infected by the same rhizobia are called cross-inoculation groups (Table 1.). Sometimes the correct type of bacteria that can form nodules with the legume you are planting is already present in the field. In order to ensure that the correct type of bacteria is ready and waiting for your germinating seed in the soil, farmers commonly practice inoculation with specific groups of bacteria recommended for your legume type.

Table 1. Cross-inoculation groups of legumes and rhizobia. Legume group Manufacturers inoculation group code Rhizobia species Alfalfa and sweetclover

A

Rhizobium meliloti True clovers B R. trifolii Peas and vetch (true) C R. leguminosarum Soybean S Bradyrhizobium japonicum Birdsfoot trefoil K R. loti Crownvetch M Rhizobium spp. Is Inoculation of My Legumes a Requirement for Good Growth?

Inoculation is recommended when the field has no past history of growth of your particular legume, or when you have a high value crop for which you want to ensure successful growth. Often, inoculant rhizobia can remain viable in the soil without the presence of a legume for years, and then be ready to form nodules when its host plant is sown. Field history that includes a legume can increase the soil rhizobia population and result in improved nodulation (Mothapo et al., 2011). Specifically, inoculation is recommended if the field has been out of host plant production for 3–5 years, or never planted to the host. Further, inoculation can help increase rhizobia populations in fields with unfavorable environmental conditions for the bacteria's long-term survival, such as pH below 6.0, extremely sandy soils, or periodically-flooded conditions. Past history that includes a diversity of legume species—common in organic systems—has been shown to increase the diversity of rhizobia types present in the field (Grossman et al., 2011).

How Do I Inoculate My Legumes?

Take care of your inoculants—they are alive!

Inoculants come in many forms, but the most common is as a bacteria-infused peat that has a black, dust-like appearance. The bacteria on the peat particles may not look like much, but they are indeed alive, and should be treated with care. Although peat has been shown to mediate unfavorable conditions such as high temperatures and long storage times, certain precautions are necessary in order to increase inoculant effectiveness.

Inoculant packages come with an expiration date that should be heeded—use of an inoculant past its expiration date could mean that you are adding bacteria to your seed that are not alive or healthy. Treat the inoculant as you might treat a living organism—don’t leave it in the sun for extended periods of time, and store it in a cool dry place when not in use, such as a refrigerator. Many manufacturer recommendations offer a suggested temperature of 40°F.

Inoculants can be added to the soil or directly to your seed prior to planting.

In direct-soil application, granular inoculants can be added to the soil via the fertilizer box of a standard planter or drill, as long as the box has no history of substances prohibited in organic production, or the box is thoroughly cleaned prior to use. Flow of the inoculant should be calibrated in order to ensure a steady flow of material to the field. Frozen concentrated and liquid inoculant cultures are also available. In this case, the frozen cultures should be thawed and diluted according to manufacturers' directions and added to a water tank for field application in the seed row. Field application of inoculants requires more volume of inoculant to be added than seed-applied, in order to ensure the inoculant comes in contact with your legume seed.

In seed-applied inoculant, a more common practice among small-scale organic producers, the bacteria is mixed with the seed prior to planting. Seed should not be mixed in a small space such as a planter box, but instead on a large surface where all of the seeds have the opportunity to come into contact with the inoculant. Suggested places for mixing your seed include the bed of your pickup truck, a tarp on the ground, or in a tub.

Stickers—adhesives that can be used to ensure that the peat inoculant adheres to your seed—are commonly used to ensure good contact between the seed and bacteria. Research has shown increase in nodulation when stickers are used. Stickers can be commercially purchased or made at home using dilutions of milk or molasses (1 part sticker to 10 parts water is common). To use a sticker, mix seeds with just enough sticker to moisten the seeds, then add the inoculant to the moistened seeds. Be careful not to add too much liquid or the moisture could cause premature germination of your seeds. Air dry your seeds in the shade, then plant within 24 hours. Air drying the seeds will keep the moist seeds and inoculum from adhering to and plugging up your planter. If planting is not possible immediately after inoculation, inoculate again. Some seed comes pre-inoculated with a sticker. This type of inoculant should be treated with the same precautions as other types.

How Much Inoculant Should I Use?

The amount of inoculant to add to your seeds or field often depends on the length of time that has elapsed since the field was last inoculated. For new plantings, follow the inoculant manufacturer's directions on the package. Some farmers have found that after an initial inoculation event no inoculation is necessary in future years for good nodulation to occur. No general recommendation can be provided regarding survival of rhizobia in a field after a single inoculation event, as survial depends on individual field conditions such as soil type, pH, soil moisture, and rhizobia type.

What are the Precautions for Organic Farming Systems?

Growers should be aware of specific issues when using purchased inoculants in organic production of grains, cover-, and forage crops. Of interest to certified organic growers is the prohibition on the use of genetically modified organisms, ionizing radiation, or sewage sludge in the production of the inoculants. Some inoculants are produced using recombinant DNA technology—such inoculants cannot be used in organic production.  

The Organic Materials Review Institute (OMRI) is a non-profit organization that provides external review of products for use in organic systems. When the OMRI review panel approves both the active and non-active (inert) ingredients of a product for compliance, then the product becomes OMRI-listed and can display an "OMRI-approved" label. A critical part of organic certification is maintenence of inoculant supply company documentation that provides inoculant ingredients, or certifies OMRI approval. Many companies have issued such information as written responses that are available through the internet. Various OMRI-approved inoculants are produced by Becker Underwood, and INTEX microbials. A full list of OMRI-approved inoculants can be found on the OMRI website

IMPORTANT: Before using any input product in your organic farming system, make sure that the brand name product is listed in your Organic System Plan and approved by your USDA-approved certifier. Note that, although OMRI and WSDA lists are good places to identify potentially useful products, all products that you use MUST be approved by your USDA-accredited certifier. For more information on how to determine whether a product can be used on your farm, see Can I Use This Input on My Organic Farm?

References Cited
  • Grossman, J. M., M. E. Schipanski, T. Sooksanguan, and L. E. Drinkwater. 2011. Diversity of rhizobia nodulating soybean [Glycine max (Vinton)] varies under organic and conventional management. Applied Soil Ecology 50: 14–20. (Available online at: http://dx.doi.org/10.1016/j.apsoil.2011.08.003) (verified 20 April 2012).
  • Mothapo, N., J. Grossman, and J., Maul. 2011. Hairy vetch cultivation history affects nodulation and biological nitrogen fixation across host genotypes. ASA-CSSA-SSSA International Annual Meetings, Oct 16–19, 2011, San Antonio, TX. (Available online at: http://a-c-s.confex.com/crops/2011am/webprogram/Paper66799.html) (verified 20 April 2012).
Additional Resources
  • Beegle, D. 2001. Soil fertility management for forage crops establishment. Agronomy Facts 31-B. Penn State, College of Agricultural Sciences, Cooperative Extension. (Available online at: http://cropsoil.psu.edu/extension/facts/agronomy-facts-31b) (verified 20 April 2012).
  • Durst, D., and S. Bosworth. 1986. Inoculation of forage and grain legumes. Agronomy Facts 11. Penn State Department of Crop and Soil Sciences, Cooperative Extension. (Available online at: http://cropsoil.psu.edu/extension/facts/agronomy-facts-11) (verified 20 April 2012).
  • Park, S., C. Cao, and B. B. McSpadden Gardener. 2010. Inoculants and soil amendments for organic growers. Fact Sheet SAG-17-10. The Ohio State University Extension. (Available online at: http://ohioline.osu.edu/sag-fact/pdf/0017.pdf) (verified 21 May 2012).

 

This is an eOrganic article and was reviewed for compliance with National Organic Program regulations by members of the eOrganic community. Always check with your organic certification agency before adopting new practices or using new materials. For more information, refer to eOrganic's articles on organic certification.

eOrganic 4439

Brassicas and Mustards for Cover Cropping in Organic Farming

New/updated @ eXtension - Fri, 05/31/2019 - 15:16

Source:

Adapted from: Clark, A. (ed.) 2007. Managing cover crops profitably. 3rd ed. National SARE Outreach Handbook Series Book 9. National Agricultural Laboratory, Beltsville, MD. (Available online at: http://www.sare.org/publications/covercrops.htm) (verified 24 March 2010). Note: For this article, all information from the source that does not comply with organic certification regulations has been removed.

Type: Annual (usually winter or spring; summer use possible)
Roles: Prevent erosion, suppress weeds and soilborne pests, alleviate soil compaction and scavenge nutrients
Mix with: Other brassicas or mustards, small grains or crimson clover
Species: Brassica napus, Brassica rapa, Brassica juncea, Brassica hirta, Raphanus sativus, Sinapsis alba

Nomenclature Note: The cover crops described in this article all belong to the family Brassicaceae. Most, but not all, of the species belong to the genus Brassica. In common usage, the various species are sometimes lumped together as "brassicas" and sometimes distinguished as "brassicas" vs. "mustards." In this article, we will use brassicas as an umbrella term for all species; mustards will be used to distinguish that subgroup, which has some unique characteristics.

Adaptation Note: This article addresses management of eight different cover crop species with varying degrees of winter hardiness. Some can be managed as winter or spring annuals. Others are best planted in late summer for cover crop use but will winter-kill. Consult the information on management, winter hardiness and winter vs. spring use and the examples throughout the chapter, then check with local experts for specific adaptation information for your brassica cover crop of choice.

Introduction

Brassica and mustard cover crops are known for their rapid fall growth, great biomass production, and nutrient scavenging ability. However, they are attracting renewed interest primarily because of their pest management characteristics. Most Brassica species release chemical compounds that may be toxic to soil borne pathogens and pests, such as nematodes, fungi and some weeds. The mustards usually have higher concentrations of these chemicals.

Brassicas are increasingly used as winter or rotational cover crops in vegetable and specialty crop production, such as potatoes and tree fruits. There is also growing interest in their use in row crop production, primarily for nutrient capture, nematode trapping, and biotoxic or biofumigation activity. Some brassicas have a large taproot that can break through plow pans better than the fibrous roots of cereal cover crops or the mustards. Those brassicas that winter-kill decompose very quickly and leave a seedbed that is mellow and easy to plant in.

With a number of different species to consider, you will likely find one or more that can fit your farming system. Don't expect brassicas to eliminate your pest problems, however. They are a good tool and an excellent rotation crop, but pest management results are inconsistent. More research is needed to further clarify the variables affecting the release and toxicity of the chemical compounds involved.

Mustard mix 'Caliente' cover crop in bloom
Figure 1. Mustard mix 'Caliente' in bloom at Kenagy Family Farm in Albany, OR. Photo credit: Alex Stone, Oregon State University.

Benefits Erosion control and nutrient scavenging

Brassicas can provide greater than 80% soil coverage when used as a winter cover crop (Haramoto and Gallandt, 2004). Depending on location, planting date and soil fertility, they produce up to 8,000 lb. biomass/A. Because of their fast fall growth, brassicas are well-suited to capture soil nitrogen (N) remaining after crop harvest. The amount of nitrogen captured is mainly related to biomass accumulation and the amount of N available in the soil profile.

Because they immobilize less nitrogen than some cereal cover crops, much of the N taken up can become available for uptake by main crops in early to late spring. Brassicas can root to depths of 6 feet or more, scavenging nutrients from below the rooting depth of most crops. To maximize biomass production and nutrient scavenging in the fall, brassicas must be planted earlier than winter cereal cover crops in most regions, making them more difficult to fit into grain production rotations.

Pest management

All brassicas have been shown to release biotoxic compounds or metabolic byproducts that exhibit broad activity against bacteria, fungi, insects, nematodes, and weeds. Brassica cover crops are often mowed and incorporated to maximize their natural fumigant potential. This is because the fumigant chemicals are produced only when individual plant cells are ruptured.

Pest suppression is believed to be the result of glucosinolate degradation into biologically active sulfur containing compounds call thiocyanates (Gardiner et al., 1999; Petersen et al., 2001). To maximize pest suppression, incorporation should occur during vulnerable life-stages of the pest (Williams and Weil, 2004).

The biotoxic activity of brassica and mustard cover crops is low compared to the activity of commercial fumigants (Smith et al., 2005). It varies depending on species, planting date, growth stage when killed, climate, and tillage system. Be sure to consult local expertise for best results.

The use of brassicas for pest management is in its infancy. Results are inconsistent from year to year and in different geographic regions. Different species and varieties contain different amounts of bioactive chemicals. Be sure to consult local expertise and begin with small test plots on your farm.

Disease management

In Washington, a SARE-funded study of brassica green manures in potato cropping systems compared winter rape (Brassica napus) and white mustard (Sinapis alba) to no green manure, with and without herbicides and fungicides. The winter rape system had a greater proportion of Rhizoctonia-free tubers (64%) than the white mustard (27%) and no green manure (28%) treatments in the non-fumigated plots. There was less Verticillium wilt incidence with winter rape incorporation (7%) than with white mustard (21%) or no green manure incorporation (22%) in non-fumigated plots (Collins et al., 2006).

In Maine, researchers have documented consistent reductions in Rhizoctonia (canker and black scurf) on potato following either rapeseed green manure or canola grown for grain (Larkin and Griffin, 2007; Larkin et al., 2006). They have also observed significant reductions in powdery scab (caused by Spongospora subterranea) and common scab (Streptomyces scabiei) following brassica green manures, especially an Indian mustard (B. juncea) green manure (Larkin and Griffin, 2007; Larkin et al., 2006).

Nematode management

In Washington state, a series of studies addressed the effect of various brassica and mustard cover crops on nematodes in potato systems (Matthiessen and Kirkegaard, 2006; Melakeberhan et al., 2006; Mojtahedi et al., 1991; Mojtahedi et al., 1993; Riga et al. 2003).  The Columbia root-knot nematode (Meloidogyne chitwoodi) is a major pest in the Pacific Northwest. It is usually treated with soil fumigants costing $20 million in Washington alone. Brassicas must be planted earlier than winter cereal cover crops in most regions.

Rapeseed, arugula and mustard were studied as alternatives to fumigation. The brassica cover crops are usually planted in late summer (August) or early fall and incorporated in spring before planting mustard.

Results are promising, with nematodes reduced up to 80%, but because of the very low damage threshold, green manures alone cannot be recommended for adequate control of Meloidogyne chitwoodi in potatoes. The current recommended alternative to fumigation is the use of rapeseed or mustard cover crop plus the application of MOCAP. This regimen costs about the same as fumigation (2006 prices).

Several brassicas are hosts for plant parasitic nematodes and can be used as trap crops followed by an application of a synthetic nematicide. Washington State University nematologist Ekaterini Riga has been planting arugula in the end of August and incorporating it in the end of October.

Nematicides are applied two weeks after incorporation, either at a reduced rate using Telone or the full rate of Mocap and Temik. Two years of field trials have shown that arugula in combination with synthetic nematicides reduced M. chitwoodi to economic thresholds.

Longer crop rotations that include mustards and non-host crops are also effective for nematode management. For example, a three-year rotation of potatoes>corn>wheat provides nearly complete control of the northern root-knot nematode (Meloidogyne hapla) compared to methyl bromide and other broad-spectrum nematicides.

However, because the rotation crops are less profitable than potatoes, they are less commonly used. Not until growers better appreciate the less tangible long-term cover crop benefits of soil improvement, nutrient management, and pest suppression will such practices be more widely adopted.

In Wyoming, oilseed radish (Raphanus sativus) and yellow mustard (Sinapsis alba) reduced the sugar beet cyst nematode populations by 19-75%, with greater suppression related to greater amount of cover crop biomass (Koch, 1995). In Maryland, rapeseed, forage radish, and a mustard blend did not significantly reduce incidence of soybean cyst nematode (which is closely related to the sugar beet cyst nematode). The same species, when grown with rye or clover, did reduce incidence of stubby root nematode (R. Weil, personal communication, 2007). Also in Maryland, in no-till corn on a sandy soil, winter-killed forage radish increased bacteria-eating nematodes, rye and rapeseed increased the proportion of fungal feeding nematodes, while nematode communities without cover crops were intermediate. The Enrichment Index, which indicates a greater abundance of opportunistic bacteria–eating nematodes, was 23% higher in soils that had brassica cover crops than the unweeded control plots. These samples, taken in November, June (a month after spring cover crop kill), and August (under no-till corn), suggest that the cover crops, living or dead, increased bacterial activity and may have enhanced nitrogen cycling through the food web (R. Weil, personal communication, 2007).

Weed management

Like most green manures, brassica cover crops suppress weeds in the fall with their rapid growth and canopy closure. In spring, brassica residues can inhibit small seeded annual weeds such as pigweed, shepherds purse, green foxtail, kochia, hairy nightshade, puncturevine, longspine sandbur, and barnyardgrass (Munoz and Graves), although pigweed was not inhibited by yellow mustard (Haramoto and Gallandt, 2005b).

In most cases, early season weed suppression obtained with brassica cover crops must be supplemented with cultivation to avoid crop yield losses from weed competition later in the season. As a component of integrated weed management, using brassica cover crops in vegetable rotations could improve weed control (Boydston and Al-Khatib, 2005).

In Maine, the density of 16 weed and crop species was reduced 23% to 34% following incorporation of brassica green manures, and weed establishment was delayed by two days, compared to a fallow treatment. However, other short-season green manure crops including oat, crimson clover, and buckwheat similarly affected establishment (Haramoto and Gallandt, 2004).

In Maryland and Pennsylvania, forage radish is planted in late August and dies with the first hard frost (usually December). The living cover crop and the decomposing residues suppress winter annual weeds until April and result in a mellow, weed-free seedbed into which corn can be no-tilled without any preplant herbicides. Preliminary data show summer suppression of horseweed but not lambsquarters, pigweed, or green foxtail (R. Weil, personal communication, 2007).

Mustard cover crops have been extremely effective at suppressing winter weeds in tillage-intensive, high-value vegetable production systems in Salinas, CA. Mustards work well in tillage-intensive systems because they are relatively easy to incorporate into the soil prior to planting vegetables. However, the growth and biomass production by mustards in the winter is not usually as reliable as that of other cover crops such as cereal rye and legume/cereal mixtures (Brennan and Smith, 2005).

Soil structure management

Some brassicas (forage radish, rapeseed, turnip) produce large taproots that can penetrate up to 6 feet to alleviate soil compaction (R. Weil, personal communication, 2007). This so-called "biodrilling" is most effective when the plants are growing at a time of year when the soil is moist and easier to penetrate. Their deep rooting also allows these crops to scavenge nutrients from deep in the soil profile. As the large tap roots decompose, they leave channels open to the surface that increase water infiltration and improve the subsequent growth and soil penetration of crop roots. Smaller roots decompose and leave channels through the plow plan and improve the soil penetration by the roots of subsequent crops (Williams and Weil, 2004). Most mustards have a fibrous root system, and rooting effects are similar to small grain cover crops in that they do not root so deeply but develop a large root mass more confined to the soil surface profile.

Species Rapeseed (Canola)

Two Brassica species are commonly grown as rapeseed, Brassica napus and Brassica rapa. Rapeseed that has been bred to have low concentrations of both erucic acid and glucosinolates in the seed is called canola, which is a word derived from Canadian Oil.

Annual or spring-type rapeseed belongs to the species B. napus, whereas winter-type or biennial rapeseed cultivars belong to the species B. rapa. Rapeseed is used as industrial oil while canola is used for a wider range of products including cooking oils and biodiesel. Besides their use as an oil crop, these species are also used for forage. If pest suppression is an objective, rapeseed should be used rather than canola since the breakdown products of glucosinolates are thought to be a principal mechanism for pest control with these cover crops.

Rapeseed has been shown to have biological activity against plant parasitic nematodes as well as weeds (Haramoto and Gallandt, 2004; Sattell et al., 1998). Due to its rapid fall growth, rapeseed captured as much as 120 lb. of residual nitrogen per acre in Maryland (J. Alger, personal communication, 2006). In Oregon, aboveground biomass accumulation reached 6,000 lb./A and N accumulation was 80 lb./A.

Some winter-type cultivars are able to withstand quite low temperatures (10°F) (Rife and Zeinalib, 2003). This makes rapeseed one of the most versatile cruciferous cover crops, because it can be used either as a spring- or summer-seeded cover crop or a fall-seeded winter cover crop. Rapeseed grows 3 to 5 feet tall.

Mustard

Mustard is a name that is applied to many different botanical species, including white or yellow mustard (Sinapis alba, sometimes referred to as Brassica hirta), brown or Indian mustard (Brassica juncea, sometimes erroneously referred to as canola), and black mustard [B. nigra (L.)] (Koch, 1995).

The glucosinolate content of most mustards is very high compared to the true Brassicas. In the Salinas Valley, CA, mustard biomass reached 8,500 lb./A. Nitrogen content on high residual N vegetable ground reached 328 lb. N/A (Smith et al., 2005; UC SAREP Cover Crop Resource Page). Because mustards are sensitive to freezing, winter-killing at about 25°F, they are used either as a spring/summer crop or they winter-kill except in areas with little freeze danger. Brown and field mustard both can grow to 6 feet tall.

In Washington, a wheat/mustard-potato system shows promise for reducing or eliminating the soil fumigant metam sodium. White mustard and oriental mustard both suppressed potato early dying (Verticillium dahliae) and resulted in tuber yields equivalent to fumigated soils, while also improving infiltration, all at a cost savings of about $66/acre (McGuire, 2003). McGuire (2003) provides more information about using mustard green manures to replace fumigants and improve infiltration in potato cropping systems. Mustards have also been shown to suppress growth of weeds (Boydston and Al-Khatib, 2005; Haramoto and Gallandt, 2004; Sattell et al., 1998).

Radish

The true radish or forage radish (Raphanus sativus) does not exist in the wild and has only been known as a cultivated species since ancient times. Cultivars developed for high forage biomass or high oilseed yield are also useful for cover crop purposes. Common types include oilseed and forage radish.

Daikon radish cover crop at full canopy closure
Figure 2. Daikon radish at full canopy closure, planted in August in Blacksburg, VA (Appalachian region), photographed approximately 60 days after planting. Photo credit: Mark Schonbeck, Virginia Association for Biological Farming.

Their rapid fall growth has the potential to capture nitrogen in large amounts and from deep in the soil profile (170 lb./acre in Maryland [Kremen and Weil, 2006]). Above ground dry biomass accumulation reached 8,000 lb./acre and N accumulation reached 140 lb./acre in Michigan (Ngouajio and Mutch, 2004). Below ground biomass of radishes can be as high as 3,700 lb./acre.

Oilseed radish is less affected by frost than forage radish, but may be killed by heavy frost below 25°F. Radish grows about 2 to 3 feet tall. Radishes have been shown to alleviate soil compaction and suppress weeds (Haramoto and Gallandt, 2005a; Williams and Weil, 2004).

In an Alabama study of 50 cultivars belonging to the genera Brassica, Raphanus, and Sinapis, forage and oilseed radish cultivars produced the largest amount of biomass in central and south Alabama, whereas winter-type rapeseed cultivars had the highest production in North Alabama (E. van Santen, personal communication, 2007).

Turnips

Turnips [Brassica rapa L. var. rapa (L.) Thell] are used for human and animal food because of their edible root. Turnip has been shown to alleviate soil compaction. While they usually do not produce as much biomass as other brassicas, they provide many macrochannels that facilitate water infiltration (Saini et al., 2005). Similar to radish, turnip is unaffected by early frost but will likely be killed by temperatures below 25°F.

Some brassicas are also used as vegetables (greens)

Cultivated varieties of Brassica rapa include bok choy (Chinensis group), mizuna (Nipposinica group), flowering cabbage (Parachinensis group), Chinese cabbage (Pekinensis group) and turnip (Rapa group). Varieties of Brassica napus include Canadian turnip, kale, rutabaga, rape, swede, swedish turnip, and yellow turnip. Collard, another vegetable, is a cabbage, B. oleracea var. acephala. Brassica juncea is consumed as mustard greens.

A grower in Maryland reported harvesting the larger roots of forage radish (cultivar 'Daikon') cover crop to sell as a vegetable. In California, broccoli reduced the incidence of lettuce drop caused by Sclerotinia minor (Hao and Subbarao, 2006).

Agronomic Systems

Brassicas must be planted earlier than small grain cover crops for maximum benefits, making it difficult to integrate them into cash grain rotations. Broadcasting seeding (including aerial seeding) into standing crops of corn or soybean has been successful in some regions (Krishnan et al., 1998). Brassica growth does not normally interfere with soybean harvest, although it could be a problem if soybean harvest is delayed. The shading by the crop canopy results in less cover crop biomass and especially less root growth, so this option is not recommended where the brassica cover crop is intended to alleviate compaction.

In a Maryland SARE-funded project, dairy farmers planted forage radish immediately after corn silage harvest. With a good stand of forage radish, which winter-kills, corn can be planted in early spring without tillage, resulting in considerable savings. The N released by the decomposed forage radish residues increased corn yield boost in most years (Weil, 2007). This practice is particularly useful when manure is fall-applied to corn silage fields. (For more information see SARE Project Report LNE03-192, Multipurpose Brassica cover crops for sustaining Northeast farmers).

Vegetable systems

Fall-planted brassica cover crops fit well into vegetable cropping systems following early harvested crops. White mustard and brown mustard have become popular fall-planted cover crops in the potato producing regions of the Columbia Basin of eastern Washington.

Planted in mid- to late-August, white mustard emerges quickly and produces a large amount of biomass before succumbing to freezing temperatures. As a component of integrated weed management, using brassica cover crops in vegetable rotations could improve weed control (Boydston and Al-Khatib, 2005).

Winter-killed forage radish leaves a nearly weed- and residue-free seedbed, excellent for early spring "no-till" seeding of crops such as carrots, lettuce, peas and sweet corn. This approach can save several tillage passes for weed control in early spring and can take advantage of the early nitrogen release by the forage radish. Soils warm up faster than under heavy residue, and because no seedbed preparation or weed control is needed, the cash crop can be seeded earlier than normal.

Management Establishment

Most Brassica species grow best on well drained soils with a pH range of 5.5 to 8.5. Brassicas do not grow well on poorly drained soils, especially during establishment. Winter cover crops should be established as early as possible. A good rule of thumb is to establish brassicas about four weeks prior to the average date of the first 28°F freeze. The minimum soil temperature for planting is 45°F; the maximum is 85°F.

Winter hardiness

Some brassicas and most mustards may winter-kill, depending on climate and species. Forage radish normally winter-kills when air temperatures drop below 23°F for several nights in a row. Winter hardiness is higher for most brassicas if plants reach a rosette stage between six and eight leaves before the first killing frost. Some winter-type cultivars of rapeseed are able to withstand quite low temperatures (10°F) (Rife and Zeinalib, 2003).

Late planting will likely result in stand failure and will certainly reduce biomass production and nutrient scavenging. Planting too early, however, may increase winterkill in northern zones (T. Griffin, personal communication, 2007).

In Washington (Zone 6), canola and rapeseed usually overwinter, mustards do not. Recent work with arugula (Eruca sativa) shows that it does overwinter and may provide similar benefits as the mustards (Mustard green manures). In Michigan, mustards are planted in mid-August, and winter-kill with the first hard frost, usually in October. When possible, plant another winter cover crop such as rye or leave strips of untilled brassica cover crop rather than leave the soil without growing cover over the winter (Snapp et al., 2006). In Maine, all brassica and mustards used as cover crops winter-kill (T. Griffin, personal communication, 2007).

Winter vs. spring annual use

Brassica and mustard cover crops can be planted in spring or fall. Some species can be managed to winter-kill, leaving a mellow seedbed requiring little or no seedbed preparation. For the maximum benefits offered by brassicas as cover crops, fall-planting is usually preferable because planting conditions (soil temperature and moisture) are more reliable and the cover crops produce more dry matter.

In Maryland, rapeseed and forage radish were more successful as winter- rather than spring-annual cover crops. The early-spring-planted brassicas achieved about half the quantities of biomass and did not root as deeply before bolting in spring (R. Weil, personal communication, 2007). In Michigan, mustards can be planted in spring following corn or potatoes or in fall into wheat residue or after snap beans. Fall seedings need about 90 growing-degree-days to produce acceptable biomass, which is usually incorporated at first frost (usually October). Spring seeding is less reliable due to cool soil temperatures, and its use is limited mostly to late-planted vegetable crops (Snapp et al., 2006). In Maine, brassicas are either planted in late summer after the cash crop and winter-kill, or they are spring-seeded for a summer cover crop (T. Griffin, personal communication, 2007). Rapeseed planted in late spring to summer has been used with some success in the mid-Atlantic region to produce high biomass for incorporation to biofumigate soil for nematodes and diseases prior to planting strawberries and fruit trees.

Mixtures

Mix with small grains (e.g. oats, rye), other brassicas, or legumes (e.g. clover). Brassicas are very competitive and can overwhelm the other species in the mixture. The seeding rate must be adjusted to ensure adequate growth of the companion species. Consult local experts and start with small plots or experiment with several seeding rates.

Washington farmers use mixtures of white and brown mustard, usually with a greater proportion of brown mustard. In Maryland and Pennsylvania, farmers and researchers seed the small grain and forage radish in separate drill rows rather than mixing the seed. This is done by taping closed alternate holes in the two seeding boxes of a grain drill with both small seed and large seed boxes. Two rows of oats between each row of forage radish has also proven successful (R. Weil, personal communication, 2007). Rye (sown at 48 lb./A) can be grown successfully as a mixture with winter-killing forage radish (13 lb./A).

Killing

Brassica cover crops that do not winter-kill can be terminated in spring by mowing, and/or incorporating above-ground biomass by tillage before the cover crop has reached full flower. Rolling may also be used to kill these covers if they are in flower.

Another no-till method for terminating mature brassicas is flail mowing. Be sure to evenly distribute residue to facilitate planting operations and reduce allelopathic risk for cash crops. As mentioned above, many producers incorporate brassica residues using conventional tillage methods to enhance soil biotoxic activity, especially in plasticulture systems. Brassica pest suppression may be more effective if the cover crop is incorporated.

Seed and planting

Because Brassica spp. seed may be scarce, it is best to call seed suppliers a few months prior to planting to check on availability. Brassica seeds in general are relatively small; a small volume of seed goes a long way.

  • Rapeseed (Canola): Drill 5 to 10 lb./A no deeper than ¾ in. or broadcast 8 to 14 lb./A.
  • Mustard: Drill 5 to 12 lb./A, ¼–¾ in. deep or broadcast 10 to 15 lb./A.
  • Radish: Drill 8 to 12 lb/A, ¼–½ in. deep, or broadcast 12 to 20 lb./A. Plant in late summer or early fall after the daytime average temperature is below 80°F.
  • Turnip: Drill 4 to 7 lb./A about ½ in. deep or broadcast 10 to 12 lb./A. Plant in the fall after the daytime average temperature is below 80°F.
Nutrient management

Brassicas and mustards need adequate nitrogen and sulfur fertility. Brassica sulfur (S) nutrition needs and S uptake capacity exceed those of many other plant species, because S is required for oil and glucosinolate production. A 7:1 N:S ratio in soils is optimum for growing rape, while N:S ratios ranging from 4:1 to 8:1 work well for brassica species in general.

Ensuring sufficient N supply to brassicas during establishment will enhance their N uptake and early growth. Some brassicas, notably rape, can scavenge P by making insoluble P more available to them via the excretion of organic acids in their root zone (Grinsted et al., 1982).

Brassicas decompose quickly. Decomposition and nutrient turnover from roots (C:N ratios of 20 to 30) is expected to be slower than that from shoots (C:N ratios of 10 to 20), but overall faster than that of winter rye. A winter-killed radish cover crop releases plant available nitrogen especially early in spring, so it should be followed by an early-planted, nitrogen-demanding crop to avoid leaching losses (R. Weil, personal communication, 2007).

Comparative Notes

Canola is more prone to insect problems than mustards, probably because of its lower concentration of glucosinolates. In the Salinas Valley, which has much milder summer and winter temperatures than the Central Valley of California, brassica cover crops are generally less tolerant of suboptimal conditions (i.e., abnormally low winter temperatures, low soil nitrogen, and waterlogging), and hence are more likely to produce a nonuniform stand than other common cover crops (Brennan and Smith, 2005).

Precautions

The use of brassicas for pest management is in its infancy. Results are inconsistent from year to year and in different geographic regions. Be sure to consult local expertise and begin with small test plots on your farm.

Biotoxic activity can stunt cash crop growth, thus avoid direct planting into just-killed green residue. Brassica cover crops should not be planted in rotation with other brassica crops such as cabbage, broccoli, and radish because the latter are susceptible to similar diseases. Also, scattered volunteer brassica may appear in subsequent crops. Controlling brassica cover crop volunteers that come up in brassica cash crops would be challenging if not impossible.

Black mustard (Brassica nigra) is hardseeded and could cause weed problems in subsequent crops (Boydston and Al-Khatib, 2005). Rapeseed contains erucic acid and glucosinolates, naturally occurring internal toxicants. These compounds are antinutritional and are a concern when feeding to livestock. Human consumption of brassicas has been linked to reducing incidence of cancer. All canola cultivars have been improved through plant breeding to contain less than 2% erucic acid.

Winter rape is a host for root lesion nematode. In a SARE-funded study in Washington, root lesion nematode populations were 3.8 times higher in the winter rape treatment than in the white mustard and no green manure treatments after green manure incorporation in unfumigated plots. However, populations in the unfumigated winter rape treatment were below the economic threshold both years of the study (Eberlein, 2000). For more information, see SARE Project Reports SW95-021, Brassica Green Manure Systems for Weed, Nematode, and Disease Control in Potatoes and SW02-037, Promoting Sustainable Potato Cropping Systems. Rapeseed may provide overwintering sites for harlequin bug in Maryland (R. Weil, personal communication, 2007).

Contributors: Guihua Chen, Andy Clark, Amy Kremen, Yvonne Lawley, Andrew Price, Lisa Stocking, and Ray Weil.

References and Citations

 

This is an eOrganic article and was reviewed for compliance with National Organic Program regulations by members of the eOrganic community. Always check with your organic certification agency before adopting new practices or using new materials. For more information, refer to eOrganic's articles on organic certification.

eOrganic 2554

Woodleaf Farm Soil Management System

New/updated @ eXtension - Fri, 05/31/2019 - 14:50

eOrganic authors:

Carl Rosato, Woodleaf Farm

Helen Atthowe, Woodleaf Farm

Alex Stone, Oregon State University

  This article is part of the Woodleaf Farm Organic Systems Description.

Introduction

The goal of Woodleaf Farm's soil management system is to build soil organic matter and balance soil nutrients in order to produce healthy trees, optimal annual growth, and high-quality, flavorful fruit.

Woodleaf started with heavy, poorly drained soils typical of foothills pine/oak forests in this region (Overview Fig.1 Area Map). Soils were classified as NRCS capability class VII, poor for agricultural use (Overview Fig. 2 Farm Fields & Soils Map). Over time, Carl Rosato's soil building system has transformed these poor soils into fertile, well-drained soils with high organic matter content. The fundamental components of the soil management system (Table 1) include the following:

Woodleaf supplements soil nutrients with soil- and foliar-applied materials, based on soil test results.

Outcomes Soil Organic Matter

In the 1980s and 1990s, soil organic matter (SOM) ranged from 2 to 3%. From 2000 through 2014, it was 4 to 6% (Fig. 1). In the 1980s, average SOM was 2.2%. By 2014, it had climbed to 5.1%.

Over the same period, average cation exchange capacity (CEC) increased from 9.5 to 11.7 meq/100g (Fig. 2).

Soil nitrate-nitrogen (N) levels have generally decreased, from an average of 23 ppm in the early 1980s to an average of 9 ppm in 2014 (Fig. 3). Levels of total N (organic plus nitrate ammonium N) are relatively high, ranging from 4,054 ppm in the oldest field to 2,564 ppm in the youngest field (Fig. 4).

Soil Nutrient Balance

Soil samples taken since 1982 indicate that all soil macronutrients—potassium (K), phosphorus (P), calcium (Ca), and magnesium (Mg)—have increased and are generally within Woodleaf's target ranges (Table 2).

Soil levels of micronutrients have generally decreased or remained stable over the past 10 years, except for zinc (Zn), which increased from an average of 5.8 ppm in the 1980s and early 1990s to an average of 7.9 ppm in 2014 (Fig. 5) and copper (Cu), which increased rapidly to excessive levels in the late 1990s and early 2000s (17.4 – 26.1 ppm) during/after the time Cu was sprayed for peach leaf curl disease (until the early 1990s). Cu levels stabilized after spraying stooped and in 2014 averaged 5.2 ppm (Fig. 6).

Despite regular applications of foliar sulfur (S), gypsum (to add Ca and S), Solubor® (for boron, B), and manganese (Mn), some nutrients remain below Carl's targets:

Tree Growth and Nutrition

Annual tree growth ranges from 10 to 20 inches.

Leaf tissue N is in the adequate average range for peach trees (Fig. 10). Records from O'Henry peaches growing in the same field in 1994 and 2014 indicate a slight increase, from 2.4 to 2.74%.

Leaf tissue P, K, Mg, and Ca is within or above the adequate range (Fig. 10). Only leaf tissue S is below the adequate range. Levels of these nutrients in Woodleaf fruit were similar to those from two other regional organic peach farms, but all were below USDA averages.

Fruit N is at least as high as that in samples from two other organic farms in the region (Fig. 11).

Fruit levels of sodium (Na), iron (Fe), Mn, B, Cu, and Zn in Woodleaf peaches vary in comparison to those from two other organic peach farms and to USDA averages (Fig. 12).

Fruit Quality

Disease and insect damage to fruit is low.

Key Practices Living Mulch and Organic Plant Residues

Woodleaf surface-applies several kinds of plant residues throughout the year. The goal is to link N mineralization to SOM decomposition, thus avoiding nutrient loss to leaching, and to build soil C.

Organic residues applied are as follows:

Through 1991, off-farm composted cow manure with straw bedding was applied to Woodleaf's oldest fields (1, 2, and 3), at approximately 10 tons/A. In 1992, Woodleaf stopped using manure and began to bring in municipal yard waste compost.

Living Mulch

When orchards are planted or renovated, a perennial grass/clover living mulch is seeded between and beneath crop rows immediately after tillage. Seed is planted in the fall, by October 15, with a cyclone seeder.

The seed mix includes low-growing, shade- and drought-tolerant grasses, and 5% New Zealand white clover (Trifolium repens). Over time, the groundcover becomes a mix of grasses, clover, and weeds. Above-ground biomass is currently made up of approximately 70% grass species and 30% broadleaf weeds and clover. Dominant grass species include orchardgrass (Dactylis glomerata), California brome (Bromus carinatus), Blando brome (B. mollis), and tall fescue (Festuca arundinacea).

The living mulch is mowed two to four times annually. The height of the living mulch before each mowing ranges from 1 to 3 feet. On average, approximately 2-4 tons/A of hay mulch (dry weight) are added to the soil surface each year.

The living mulch residue has not been analyzed for nutrient content, and seasonal/annual variation is likely. However, an approximate nutrient contribution can be estimated, based on published averages for mixed grass hay (Parnes, 1990). Table 3 shows the approximate nutrient contribution from 2 tons/A of mowed living mulch (dry weight).

Clover in the living mulch adds some N through N-fixation. The other nutrients are taken up from and returned to the soil. Regular mowing allows these nutrients to be continually recycled.

The year-round growing roots of the living mulch also reduces N-leaching by the winter rains common in northern California and may help to retain other nutrients prone to leaching, such as S, Ca, Mn, and B.

Chipped Branches

Green leaves and young branches are applied to the soil after pruning in late summer/fall and spring. Branches are from 0.5 to 1.25 inches in diameter. These materials have a higher carbon to nitrogen ratio (C:N) and degrade more slowly than the living mulch.

Pruned branches are placed in row middles over the living mulch. They are broken up first with a rotary tractor-mounted mower and then mowed again with a small riding mower and blown beneath trees (see soil/insect management video).

Off-Farm Yard Waste Compost

Carl purchases yard waste compost from a municipal composting facility 20 miles from the farm. Compost consists of grass clippings and branch/leaf prunings that have been aerobically composted with a bed turner.

Compost is applied two to four times per year, usually in spring and fall. The current rate is 2 tons/A (dry weight) per application. In the past, 4-6 tons/A were applied annually. As soil fertility increases, Woodleaf is experimenting with reduced rates.

Compost is applied primarily to row middles with a compost spreader. Some is blown under trees. Compost is irrigated into the living mulch immediately following application.

Nutrient analysis of off-farm yard waste compost is shown in Table 4.

No-till/Reduced Tillage

Tillage is an important part of many organic farming systems that utilize plant residues for soil fertility management, particularly annual horticultural systems. However, tillage is used very little at Woodleaf.

Tillage occurs only when fields are brought into cultivation or during renovation and replanting (every 20 or 21 years). At all other times, organic residues and fertilizers are surface-applied and usually not incorporated. Some fields have not been tilled for 21 years.

During field renovation, a front end loader is used to pry out tree stumps and remove them from the orchard. To break up the understory sod, three passes are then made using a box scraper with five rippers lowered to 8 inches.

Soil Mineral Balancing

Soil mineral (nutrient) balancing is a foundation of Woodleaf's soil management system (Table 1). Carl's system is based on years of farming experience and on research and recommendations by Neal Kinsey. Soil nutrients are supplied primarily through application of organic materials and supplemented with off-farm, purchased minerals when soil tests indicate they are needed.

Mineral Amendments

The need for mineral amendments is indicated when soil analysis shows levels of nutrients below targets (Table 2). Minerals are surface applied or incorporated at planting or during field renovation.

The targets Woodleaf is working hardest to achieve are:

  • Boron: Despite annual B applications of 10 lb/A for more than 15 years, soil B remains below Carl's target of 0.8 ppm (Fig. 7). Carl has limited annual B rates to a maximum of 10 lb/A. However, he is considering raising this ceiling.
  • Sulfur: Gypsum is applied each spring at 250 lb/A. Nonetheless, soil S is still below Carl's target of 20 ppm (Fig. 8).

The following minerals are also regularly applied:

  • Calcium: In the past, Ca was added as limestone. Currently, annual gypsum application at 250 lb/A helps increase the Ca portion of cation balance, while reducing the Mg portion, currently 18% (Fig. 13, Fig. 14, and Fig. 15). For information on how Carl calculates Ca and Mg rates, see Calcium and Magnesium Amendment Calculation below.
  • Manganese: Despite regular Mn applications, soil Mn remains below Carl's target of 15 ppm (Fig. 9).

Minerals are also applied annually as a foliar mineral mix.

Carl's soil test results, mineral balancing targets, and inputs are presented in Table 2.

Calcium and Magnesium Amendment Calculation

Carl's formula to determine Ca and Mg application rates is:

  • Ca rate (lb/A) = [CEC x target %Ca (68%) x 400] – current soil Ca (lb/A)
  • Mg rate (lb/A) = [CEC x target %Mg (12–18%) x 240] – current soil Mg (lb/A)

Sample Ca calculation for a soil with a CEC of 10.0 and Ca of 1,060 ppm:

  1. Convert from ppm (as reported on soil tests) to lb/A. Multiply ppm by two: 1,060 x 2 = 2,120 lb Ca.
  2. Insert the formula: 10 x 0.68 x 400 = 2,720 lb Ca needed to reach the target. Current soil Ca is 2,120 lb/A, so 600 lb/A Ca needs to be applied (2,720 – 2,120 = 600 lb).
  3. A ton of limestone generally contains 600 lb Ca (depending on source), so 1 ton/A lime is needed to raise soil Ca to 68%.
Analysis: Integrating Practice and Research

The goal of an organic soil management system is to build SOM and enhance soil microbial activity, rather than relying on quick-release fertilizers to directly feed crops. Decomposition, mineralization of plant-available nutrients, and nutrient retention are the foundations of soil ecosystem functions on organic farms. As organic matter decomposes, nutrients such as N, P, and K are mineralized and made available to plants.

Soil microbes play a role in all of these processes (Kramer, 2006). In turn, soil microbial biomass and activity are regulated by the quantity and quality of SOM, C, and N inputs (Fierer, 2009; Kallenbach, 2011). Research has shown that total C content (Drinkwater, 1998; Kong, 2005) and/or lability (ease of decomposition) of organic matter (Marriott, 2006; Smukler, 2008; Kallenbach, 2011) determine how organic amendments will affect microbial biomass by affecting the rate of decomposition and N mineralization. Materials with higher C content tend to decompose more slowly, thus releasing N slowly over the season.

Organic amendments such as manure, grass and/or legume cover crops, mulches, and compost vary in C content and C:N ratio. Therefore, they vary in their rate of decomposition and in how they stimulate microbial biomass.

Woodleaf Farm applies several kinds of plant residues throughout the year—mowed living mulch, chipped branches, and yard waste compost. These materials vary in how easily their C is degraded. Overall, however, Carl maintains high levels of C in proportion to N, with the following results:

  • N and other nutrients are supplied gradually from the reservoir of SOM as crops need them.
  • Leaching losses are minimized due to gradual N mineralization.
  • The microbial community is dominated by fungi, which flourish during early stages of residue breakdown.
  • Carl balances the high-C organic materials with green organic matter by regularly mowing the living mulch. This prevents N immobilization, which could be a problem if too much C were applied.
  • Woodleaf's N and C cycling system works in a synergistic manner with its biological insect pest management system.
System Evaluation

In 2014, Woodleaf evaluated its apparently successful N-cycling system by looking at fruit quality, leaf tissue nutrient concentrations, soil organic N, and other soil nutrient levels. Small sample sizes were used in this evaluation; funding for a more complete evaluation with larger sample sizes would be preferable.

Method

Woodleaf performed fruit tissue analysis on three random samples (two fruits per sample) of O'Henry peaches from field 2 (in a location where the same variety had been replanted and grown since 1985). Results were compared to three random samples (six fruits) of O'Henry peaches from two other successful long-term organic farms in northern California. Results were also compared to the USDA average nutritional content for peaches.

Leaf tissue samples were taken from the same rows as the fruit samples. Carl compared results to tissue nutrient concentrations in O'Henry peach trees from the same field in 1994 and to normal average ranges reported by A&L Western Laboratories, Modesto, California.

Soil samples were taken from the same rows (0- to 12-inch depth). Soil was also sampled in four other fields. Soil was analyzed for organic N (total Kjeldahl N – ammoniacal N) and nitrate-N. Trends were plotted for the period 1982–2014.

Analysis

In 2014, Woodleaf recorded a very good yield and the most economically successful year in its 34-year history. No insecticides were applied to peaches, pears, or apples, yet insect and disease damage was less than 10%.

  • Fruit tissue N: Fruit tissue N (mg/100g) was at least as high as that of fruit samples from the other two farms (Fig. 11).
  • Leaf tissue N: Leaf tissue N was in the adequate range and appears to have increased slightly since 1994 (Fig. 10).
  • Soil N: SOM has increased, while soil nitrate-N has decreased (especially in field 1, where manures and fish meal were applied until 1992) (Fig. 1 and Fig. 3).  In recent years, nitrate-N has been relatively low (averaging 9 ppm in 2014). But, organic N is now relatively high (Fig. 4).
Conclusions

Based on long-term soil test data (1982-2014), fruit, leaf tissue, and soil data (2014); low insect and disease damage (2013–2014); and financial success (2013–2015), it seems that Woodleaf's long-term use of high-C/low-N soil amendments and reduced tillage is maintaining soil health, yield, and fruit quality.

More research is needed on working farms to test the relationships among organic soil management practices, soil health, yield, and crop quality. Nevertheless, there is some scientific support for Woodleaf's success with high-C/low-N amendments.

One study conducted not far from Woodleaf (in central California) compared 13 tomato fields on 13 organic farms. Each farm used different soil amendments with different N-cycling scenarios. Some used mostly manure (higher N), while others used mainly composted yard waste (higher C). Yields were similar on all 13 farms. However, manure application was associated with increased Olsen P, increased gram-positive and gram-negative bacteria, and decreased fungal and mesofaunal markers (Bowles, 2014). Other studies report that higher P may negatively affect soil fungi abundance and activity (Fierer, 2009; de Vries, 2012). Soil management practices that support healthy soil fungal communities have been suggested as a way to increase N retention and other soil ecosystem functions (de Vries, 2012; Jackson, 2012).

It is likely that other parts of Woodleaf's soil system are just as important, especially reduced tillage and possibly mineral balancing. Several researchers have shown that tillage decreases soil microorganisms, specifically soil fungi (Calderón, 2000; Minoshima, 2007; Young-Mathews, 2010).

This article was developed with support from USDA's National Institute of Food and Agriculture through the Western Sustainable Agriculture Research and Education program under grant number SW13-017.

  References and Citations

This is an eOrganic article and was reviewed for compliance with National Organic Program regulations by members of the eOrganic community. Always check with your organic certification agency before adopting new practices or using new materials. For more information, refer to eOrganic's articles on organic certification.

eOrganic 14132

Managing Cucumber Beetles in Organic Farming Systems

New/updated @ eXtension - Fri, 05/31/2019 - 14:42

eOrganic author:

William E. Snyder, Department of Entomology, Washington State University - Pullman

This article examines the biology and management of cucumber beetles within organic farming systems.

Cucumber Beetle Biology

In North American cucurbit crops, two species of cucumber beetle present the most problems. These are the striped cucumber beetle (Aclymma vittatum in the eastern U.S. and A. trivittatum in the west) and the spotted cucumber beetle (Diabrotica undecimpunctata). Adults of the two species are easy to tell apart: the spotted cucumber beetle is somewhat larger and has dark black spots (Fig. 1a), whereas the striped cucumber beetle has long black stripes down its back (Fig. 1b).

Figure 1. Western spotted cucumber beetle (Diabrotica undecimpunctata undecimpunctata) and striped cucumber beetle (Acalymma vittatum)
Figure 1. Cucumber beetles. (a) western spotted cucumber beetle (b) Striped cucumber beetle. Photo credits: (a) Susan Ellis, Bugwood.org; (b) Clemson University - USDA Cooperative Extension Slide Series, Bugwood.org.

The western corn rootworm (Fig. 2) is related to cucumber beetles, and looks similar to the striped cucumber beetle. Although it is often observed on cucurbit crops, it causes little or no damage to them, and so it is important to correctly identify the insect in your crop. Striped cucumber beetles have black abdomens below, and pale colored legs with black "knees"; the western corn rootworm has a pale-colored abdomen and more uniformly dark legs. The black stripes on the backs of striped cucumber beetles are more distinct and exend to the tip of the wings (Delahaut, 2010; Burkness and Hutchison, 2011).

Figure 2. Western corn rootworm (Diabrotica virgifera virgifera).
Figure 2. The western corn rootworm is similar in appearance to the striped cucumber beetle, and is often observed on squash crops, but is not a squash pest. Photo credit: Winston Beck, Iowa State University, Bugwood.org.

Cucumber beetle adults generally overwinter in residue from the previous years’ cucurbit crops, or nearby. The adults first move into cucurbits in the spring and then throughout the summer, feeding on stems, foliage and flowers.

Differences between striped and spotted cucumber beetles

Despite their many similarities, there are some differences between striped and spotted cucumber beetles. Spotted cucumber beetles feed on over 200 different crop and non-crop plants, whereas striped cucumber beetles have a much stronger preference for cucurbits and rarely feed on other plants. Spotted cucumber beetles seem to be more of a pest farther south in the US, whereas striped cucumber beetles dominate farther north. Striped cucumber beetles lay eggs at the base of cucurbit plants and their larvae then feed on the roots of these plants. The spotted cucumber beetle is very different, primarily laying its eggs on corn and other grasses such that the larvae of spotted cucumber beetles are not damaging to cucurbit crops. Once the eggs hatch, the larvae spend several weeks feeding on root tissue. Thus, damage by the larvae might not be obvious just from looking at aboveground foliage—unless one attempts to pull up a plant and finds little resistance due to roots having been eaten! Larvae then pupate in the soil for about a week before emerging as adult beetles.

Cucumber beetle crop damage to cucurbit crops

Cucumber beetles damage cucurbit crops in at least three ways. First, their feeding directly stunts plants and, when flowers are eaten, can reduce fruit set (Fig. 2A). Second, cucumber beetles transmit bacterial wilt disease (Erwinia tracheiphila). More information on bacterial wilt can be found in this APSNet article on Bacterial Wilt and this Cornell Vegetable MD Online fact sheet on Cucumber Beetles, Corn Rootworms and Bacterial Wilt in Cucurbits. Third, adults scar the fruit reducing its marketability (Fig. 2B). It is primarily young cucurbit plants that are vulnerable to stunting and bacterial wilt disease, whereas damage to older plants primarily comes from fruit scarring. In fact, older plants can tolerate as much as 25% defoliation due to beetle feeding with no reduction in yield (Hoffmann et al., 2002, 2003).

Natural Enemies of Cucumber Beetles on Organic Farms Predators

wolf spider and carabid beetle
Figure 2. Predators that feed on cucumber beetles include (a) wolf spiders and (b) ground beetles. Photo credit: (a) Whitney Cranshaw, Colorado State University, Bugwood.org (b) John Goulet, Canadian Biodiversity Information Center.

Adult cucumber beetles are relatively large, by insect standards, and have a hard outer shell and so will mostly be fed upon by relatively large predators. Wolf spiders (Fig. 3A) have been shown to feed heavily on cucumber beetles in cucurbit crops (Snyder and Wise, 2001). Also, cucumber beetles avoid wolf spiders, and feed less when spiders are around even when the spiders do not actually kill the cucumber beetles (Snyder et al., 2001; Williams and Wise, 2003). Ground beetles (Fig. 3B) sometimes also feed on adult cucumber beetles (Snyder and Wise, 2001), as do other big predators such as bats (Whitaker, 1995).

A recent study searched for DNA of a cucumber beetle relative, the western corn rootworm, in the stomachs of predatory insects and spiders (Lundgren et al., 2009). The researchers believed that most of the beetle DNA that they recovered inside predators came from beetle eggs and larvae. This study found an incredible array of different predator species eating the beetles, including harvestmen (“daddy long legs”), ground and rove beetles, spiders of several kinds, and predatory mites. So, a bio-diverse community of predators may be important for biological control of cucumber beetles, rather than relying on any single predator species. Strategies to conserve predators are presented in the article, Farmscaping: Making Use of Nature’s Pest Management Services.

Insect pathogens

Most insect pathogens live in the soil, and so would most likely be effective against the root-feeding cucumber beetle larvae. Fungal pathogens and insect-attacking nematodes are both commercially available as bio-pesticides, and soil drenches of these bio-insecticides have shown some activity against cucumber beetle larvae feeding on roots (Reed et al., 1986; Choo et al., 1996; Ellers-Kirk et al., 2000). However, there is no evidence that insect pathogens effectively control adult cucumber beetles.

Parasitoids

A tachinid fly and a braconid parasitoid wasp parasitize striped cucumber beetle, and both sometimes have large impacts on striped cucumber beetles (Smyth and Hoffmann, 2010). There is some anecdotal evidence that parasitoid populations may build up over several years in organic fields, such that parasitoid impacts in organic fields may be far greater than in conventional fields. Both the fly and wasp parasitoid live inside the insect and so unfortunately there is no way to easily assess parasitoid numbers, other than rearing cucumber beetles in a cage until the parasitoids emerge.

Organic Cultural Controls for Cucumber Beetles

Organic-approved insecticides have not always been found to be effective (see below), so cultural controls may be the best option for many organic farmers. Cultural controls include crop rotation, the use of transplants rather than direct seeding, row covers, trap cropping, mulching for predator conservation, the use of reflective plastic mulches, choosing resistant varieties, and intercropping:

Rotate cucurbit crops

Cucumber beetles often overwinter near to the previous years’ cucurbit crop. So, one way to reduce pest problems the next year is to plant cucurbits as far away from last year’s crop as possible. Any barriers between last-year’s planting site and this year’s, such as hedgerows and out-buildings, may help slow beetle colonization of the new crop. However, the beetles are highly mobile and so crop rotation alone is unlikely to entirely control cucumber beetles.

Transplant rather than direct seed

Seedlings and small plants are most susceptible to cucumber beetle feeding damage and to bacterial wilt (Yao et al., 1996; Hoffmann et al., 2002, 2003). Using transplants avoids exposure to cucumber beetle feeding during the most susceptible plant stages. This also reduces the total time that cucurbit plants are in the field each season, providing less time for cucumber beetle densities to build and for disease symptoms to develop.

Use floating row covers

Floating row covers provide the most reliable defense against cucumber beetles, when left in place until flowering begins (row covers must eventually be removed to allow bees and other pollinators to visit the flowers). Downsides of row covers include their high cost and the fact that they block access to the crop for weeding. Plastic or other mulches may be combined with floating row covers to reduce these weed problems, provided that the plastic mulch is removed from the field at the end of the growing season.

Plant perimeter trap crops

With good crop rotation practices, adult cucumber beetles will always be moving into a crop from somewhere else. In perimeter cropping the main cucurbit crop is ringed by plantings of a different, highly attractive cucurbit variety. Cucumber beetles generally aggregate at field edges regardless (Luna and Xue, 2009), and attractive trap crops may further accentuate this tendency. Recent research indicates that the Blue Hubbard and buttercup varieties of Cucurbita maxima, and zucchini (C. pepo), are particularly attractive to cucumber beetles (Adler and Hazzard, 2009). Then, approved insecticides can be applied to the trap crop only, reducing total insecticide use (Cavanagh et al., 2009). Lists of highly attractive cucurbits are presented in this ATTRA publication on Cucumber Beetles (fee may apply) , and a research project funded by the USDA's Sustainable Agriculture Research and Education program generated detailed recommendations for using this strategy in cucurbits.

Apply straw mulch

Straw mulch can help reduce cucumber beetle problems in at least 3 different ways. First, mulch might directly slow beetle movement from one plant to another (Cranshaw, 1998; Olkowski, 2000). Second, the mulch provides refuge for wolf spiders and other predators from hot and dry conditions, helping predator conservation (Snyder and Wise, 2001; Williams and Wise, 2003). Third, the straw mulch is food for springtails and other insects that eat decaying plant material; these decomposers are important non-pest prey for spiders, helping to further build spider numbers (Halaj and Wise, 2002). It is important that straw mulch does not contain weed seeds and to make certain that it does not contain herbicide residues which can take years to fully break down.

Use reflective plastic mulches

Results of a study in Virginia (Caldwell and Clark, 1998) suggest that metallic-colored plastic mulches repel cucumber beetles, reducing beetle feeding damage and the transmission of bacterial wilt.

Use organic mulches

Cucumber plants grown in richly-mulched soils harbor fewer cucumber beetles than do those in soils with less organic content (Yardim et al., 2006), perhaps because organic matter fosters diverse populations of beneficial soil microorganisms that trigger the plants internal defenses (Zehnder et al., 1997).

Plant resistant/unattractive cucurbit varieties

Cucumber beetles are attracted to host plants by a chemical called cucurbitacin, which gives cucurbits their bitterness and likely is used as a defense against less-specialized herbivores (Deheer and Tallamy, 1991). The beetles absorb cucurbitacin into their bodies and use it to defend themselves against predators and pathogens (Gould and Massey, 1984; Tallamy et al., 1998). So, cucurbit varieties or species with lower cucurbitacin levels may be less attractive to cucumber beetles. Of course, market forces largely determine which cucurbits are planted, so variety selection will not be possible in many situations. Cucurbits are listed by their attractiveness to cucumber beetles in Cucumber Beetles: Organic and Biorational Integrated Pest Management .

Intercropping

A field-plot trial found that intercropping cucumbers with corn and broccoli reduced striped cucumber beetles substantially, compared to plots planted in a monoculture of cucumber (Bach, 1980). In this study intercropping also reduced the incidence of bacterial wilt disease. A recent study suggests that intercropping watermelons or musk melons with radish, nasturtium, tansy, buckwheat, cowpea or sweet clover has a similar benefit (Cline et al., 2008), suggesting that many different types of intercrops can help reduce cucumber beetle densities on cucurbits. 

Organic Chemical Controls for Cucumber Beetles

Field trials have reported somewhat inconsistent success using organic-approved insecticides to control cucumber beetles. To entirely block wilt transmission, insecticides would have to be applied repeatedly as new beetle colonists arrive, which could grow expensive. Treatment of plants just before they are transplanted into the field could help get the plants past the vulnerable early stages (Yao et al., 1996). 

IMPORTANT: Before using any pest control product in your organic farming system:

  1. read the label to be sure that the product is labeled for the crop and pest you intend to control,
  2. read and understand the safety precautions and application restrictions, and
  3. make sure that the brand name product is listed in your Organic System Plan and approved by your USDA-approved certifier.

If you are trying to deal with an unanticipated pest problem, get approval from your USDA-accredited certifier before using a product that is not listed in your plan; doing otherwise may put your organic certification at risk. Note that, although OMRI and WSDA lists are good places to identify potentially useful products, all products that you use MUST be approved by your USDA-accredited certifier. For more information on how to determine whether a pest control product can be used on your farm, see the related eOrganic article, Can I Use This Input on My Organic Farm?

Kaolin clay is reported to act by making cucurbit crops unattractive to cucumber beetles and because it gums up the beetles’ antennae and otherwise irritates them.

Pyrethrum is a naturally occurring broad-spectrum insecticide extracted from the dried flower heads of African chrysanthemums. Pyrethrum will kill both pests and beneficials, and so should be used with caution. One approach to reduce harm to beneficials is to treat only the perimeter trap crop with pyrethrum, or only particular hotspots within the main crop.

Spinosad is a general feeding deterrent and toxin. Some effectiveness has been reported in controlling cucumber beetles, although label instructions should of course always be followed. Not all spinosad formulations are organic-approved, so care must be taken in selecting any chemical used.

Other Organic Control Options

No doubt reflecting just how difficult cucumber beetles can be to control, particularly within organic farming systems, a few other more unusual approaches have been attempted with a degree of success. Both of the approaches below provide the satisfaction of instantly removing cucumber beetles.

Flaming using standard weed flamers is one way to kill cucumber beetles, although clearly this would only be used on a trap crop and not the main crop. This approach may be less effective, though, with striped cucumber beetles, which often concentrate their feeding at the base of plants, and frequently head down into the soil when disturbed.

Sucking up beetles using a vacuum (e.g., D-vac suction sampler) or a reversed leaf-blower can be an effective way to remove adult beetles, in particular from trap crops where a limited area needs to be treated (Fig. 3). It would be challenging to suck any substantial fraction of beetles from a large area.


Figure 3. A hapless undergraduate worker demonstrates the use of the D-vac bug vacuum, which can be used to suck cucumber beetles out of a cucurbit crop. Photo credit: Bill Snyder, Washington State University. 

Region-specific Information on Cucumber Beetle Biology

NOTE: Most of the controls described on these links ARE NOT ORGANIC APPROVED, although the details of local cucumber beetle biology are relevant to organic farming systems.

References and Citations
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  • Snyder, W. E., and D. H. Wise. 2000. Antipredator behavior of spotted cucumber beetles (Coleoptera: Chrysomelidae) in response to predators that pose varying risks. Environmental Entomology 29: 35–42. (Available online at: http://dx.doi.org/10.1603/0046-225X-29.1.35) (verified 11 March 2012).
  • Snyder, W. E., and D. H. Wise. 2001. Contrasting trophic cascades generated by a community of generalist predators. Ecology 82: 1571–1583. Available online at: http://www.jstor.org/stable/2679801 (verified 11 March 2012).
  • Tallamy, D. W., D. P. Whittington, F. Defurio, et al. 1998. Sequestered cucurbitacins and pathogenicity of Metarhizium anisopliae (Moniliales : Moniliaceae) on spotted cucumber beetle eggs and larvae (Coleoptera: Chrysomelidae). Environmental Entomology 27: 366–372. Available online at: http://dx.doi.org/10.1093/ee/27.2.366 (verified 11 March 2012). 
  • Whitaker, J. O. 1995. Food of the big brown bat Eptesicus fuscus from maternity colonies in Indiana and Illinois. American Midland Naturalist 134: 346–360. Available online at: http://www.jstor.org/stable/2426304 (verified 11 March 2012).
  • Williams, J.L, and D.H. Wise. 2003. Avoidance of wolf spiders (Araneae: Lycosidae) by striped cucumber beetles (Coleoptera: Chrysomelidae): laboratory and field studies. Environmental Entomology 32: 633–640. Available online at: http://dx.doi.org/10.1603/0046-225X-32.3.633 (verified 11 March 2012). 
  • Yao, C. B., G. Zehnder, E. Bauske, et al. 1996. Relationship between cucumber beetle (Coleoptera: Chrysomelidae) density and incidence of bacterial wilt of cucurbits. Journal of Economic Entomology 89: 510–514. (Available online at: http://dx.doi.org/10.1093/jee/89.2.510 510-514"> http://dx.doi.org/10.1093/jee/89.2.510 510-514) (verified 11 March 2012).
  • Yardim, E. N., N. Q. Arancon, C. A. Edwards, T. J. Oliver, and R. J. Byrne. 2006. Suppression of tomato hornworm (Manduca quinquemaculata) and cucumber beetles (Acalymma vittatum and Diabotrica undecimpunctata) populations and damage by vermicomposts. Pedobiologia 50: 23–29. Available online at: http://dx.doi.org/10.1016/j.pedobi.2005.09.001 (verified 11 March 2012).
  • Zehnder, G., J. Kloepper, C. B. Yao, and G. Wei. 1997. Induction of systemic resistance in cucumber against cucumber beetles (Coleoptera: Chrysomelidae) by plant growth-promoting rhizobacteria. Journal of Economic Entomology 90: 391–396. Available online at: http://dx.doi.org/10.1093/jee/90.2.391 (verified 11 March 2012).

 

This is an eOrganic article and was reviewed for compliance with National Organic Program regulations by members of the eOrganic community. Always check with your organic certification agency before adopting new practices or using new materials. For more information, refer to eOrganic's articles on organic certification.

eOrganic 5307

Including Barley in Organic Poultry Diets

New/updated @ eXtension - Wed, 05/22/2019 - 08:35

eOrganic author:

Dr. Jacquie Jacob Ph.D., University of Kentucky

NOTE: Before using any feed ingredient make sure that the ingredient is listed in your Organic System Plan and approved by your certifier. If you intend to feed barley to organic poultry, the barley must be certified organic.

Introduction

Barley (Hordeum vulgare) is commonly grown for malting, but can also be grown for food and animal feed. It is the main feed ingredient in some parts of western North America, and in many European countries that are less suitable for growing corn. Barley can also be grown as a pasture crop.

Barley can play an important role in crop rotation in organic production systems. It has an extensive root system that makes it able to compete with weeds; and is often used to break disease, insect, and weed cycles associated with other crops. Direct rotation with other small grains is not recommended when there are alternatives available. The small grains left behind can harbor disease or insect pests (Brown, 2003).

 

Cultivars

There are several different varieties of barley that can be classified in a number of ways:

  • Barley varieties can be classified based on head type. There are 2-row and 6-row varieties classified on the basis of the number of seeds on the stalk of the plant. The 2-row varieties are grown primarily in Europe because they are most adapted to drier climates. The 6-row varieties are commonly grown in the United States. Six-row varieties are typically higher in protein and lower in starch than 2-row varieties (Jeroch and Danicke, 1975).
  • Barley varieties can also be classified based on growth habit. There are winter and spring barley types in both the 2-row and 6-row varieties. Winter barley requires the seedlings to be exposed to cold in order to produce heads and grains normally. Therefore, winter barley is usually sown in the fall so that it will be exposed to low temperatures during the subsequent winter. Spring barley does not have the requirement for cold temperatures, so it can be sown in the spring and summer. Spring barley can play an important role in crop rotation with non-grain crops and is especially useful as it tends to break disease, insect, and weed cycles associated with other crops (Brown, 2003).
  • Waxy versus normal barley varieties differ in the composition of the starch content. The level of amylose to amylopectin is an important characteristic that affects malting, food, and feed value. Normal barley varieties contain about 27% amylose and 73% amylopectin. Waxy starch varieties have lower amylose (2-10%) and higher amylopectin (90-98%) content. Amylopectin is easier to digest than amylose.
  • Barley is typically eaten after the inedible, fibrous outer hull has been removed. Once the hull has been removed it is referred to as dehulled barley. Dehulled barley still has its bran and germ. Pearl barley is dehulled barley that has been steam-processed to remove the bran. The proportion of hull to kernel can differ widely between varieties, resulting in a wide variation in the energy content. Dehulled barley should not be confused with hull-less, or naked barley. Hull-less barley looks like hulled barley while it is growing, but as it begins to mature the hull loosens. The grain is completely removed during harvest.
  • Hull-less, or naked barley, is closely related to hulled, or covered barley. While hulled barley contains 5-6% crude fiber, the fiber levels of hull-less barley are similar to those of wheat and corn. Both hulled and hull-less barley contain beta-glucans. While the available energy content of hull-less barley is less than corn, it is superior to hulled barley.
Nutrient Composition

Nutrient content of barley (Batal and Dale, 2010)

  • Dry matter: 89%
  • Metabolizable energy: 2750 kcal/kg (1250 kcal/lb)
  • Crude protein: 11.5%
    • Methionine: 0.18%
    • Cysteine: 0.25%
    • Lysine: 0.53%
    • Tryptophan: 0.17%
    • Threonine: 0.36%
  • Crude fat: 1.9%
  • Crude fiber: 5.0%
  • Ash: 2.5%
    • Calcium: 0.08%
    • Total phosphorus: 0.42%
    • Non-phytate phosphorus: 0.15%

The available energy content of barley grain can vary widely, largely due to the presence of beta-glucans. Beta-glucans (ß-glucans) are referred to as "anti-nutritional factors" because inclusion of feedstuffs containing ß-glucans depresses nutrient digestion in poultry. The chemical structure of ß-glucans makes it difficult for poultry to digest. The ß-glucans combine with water in the intestine to form a gel that increases the thickness–or viscosity–of the intestinal contents, resulting in reduced nutrient availability. The increased viscosity can also result in increased instances of 'pasty vents' in chickens, especially chicks. Beta-glucan levels in barley are affected by the cultivar, growing conditions, geographic location, condition at harvest, and storage conditions. Commercial feed enzymes (ß-glucanase) that break down ß-glucans in the diet are now available. The enzymes reduce the viscosity of the intestinal contents and improve bird performance.

Barley also contains phytic acid, which binds phosphorus and thus reduces phosphorus availability to the animal. Compared to other grains, however, the level of phytate in barley is less than that in wheat and oats, but higher than that in rye (Bartnick and Szafrańska, 1987). The enzyme phytase is needed to break down phytate and release the bound phosphorus. Poultry are not able to produce enough phytase. Cereals do contain some phytase since it is needed to make the phosphorus available to the embryo after germination. Phytase activity is very low in most feed ingredients although slightly higher in barley, rye, triticale, wheat, and wheat byproducts (Weremko et al., 1997). However, the phytase present has not been shown to increase phosphorus availability in poultry. Low-phytate barley varieties have been developed. The phosphorus bioavailability of these low-phytate varieties is 49%, compared to 28% in normal barley. When low phytate barleys are used in poultry diets, the need for supplemental phosphorus is reduced by 50% (Salarmoini et al., 1998). In addition, use of the low-phytate varieties has been shown to increase the bioavailability of other minerals such as zinc (Linares et al., 2007).

Energy

The main component of barley grain is starch, which is the main source of energy in grains. The level and availability of the starch will affect the energy content of a cereal grain. Barley has about 60% starch on a dry matter basis (Knudsen, 1997). Starch is comprised of linked glucose (a sugar) molecules connected together, and is referred to as a polysaccharide (meaning many sugars). The connection is via α-glycosidic links that are easily broken down in the digestive tract of birds and mammals. Polysaccharides are identified by the carbon atoms of each sugar involved in the link, as well as the type of linkage involved. There are two types of linkages–alpha (α) and beta (ß)–which differ in orientation of the oxygen atom involved in the linkage. The majority of the glucose linkages in starch are α-(1→4) linkages, although there are also a few α-(1→6) linkages. These α-(1→4) and α-(1→6) linkages are easily digested by the enzymes produced in the digestive system of animals. Animals are also able to digest the α-(1→2) linkages between glucose and fructose in sucrose, the ß-(1→4) linkage between glucose and galactose in lactose, and the α-(1→1) linkages between glucose molecules. Animals are not able to digest any of the other glycosidic bonds.

There are two main classes of cereal starches: amylose and amylopectin. They have different size, shape and composition. The glucose molecules of amylose are connected to each other in linear chains with α-(1→4) linkages. In amylopectin, the chains of α-(1→4) linked glucose are connected in a highly branched structure with α-(1→6) linkages between the chains. Amylopectin is easier to digest than amylose, so the digestibility of starch in a grain depends on the type of starch present. Normal barley varieties contain about 27% amylose and 73% amylopectin. Waxy starch varieties have lower amylose (2-10%) and higher amylopectin (90-98%) content. Digestibility of waxy starch in barley has been reported to be 10% higher than for normal starch (Ankrah et al., 1999), but waxy barley grains are typically smaller and contain less starch (Tester and Morrison, 1992). In addition, waxy barley varieties have also been shown to contain more ß-glucan than normal varieties (Ankrah et al., 1999).

The other source of energy in cereal grains is lipid. With 2-3% oil, the lipid content of barley is relatively low. Some cultivars, however, have been developed with increased lipid content. This increase in lipid is associated with increased lysine. The main fatty acid present is linoleic acid.

Protein

As with most cereal grains, the protein content of barley is low compared to legume seeds (Shewry and Tatham, 1990). Cereals contain three types of proteins: storage proteins, structural and metabolic proteins, and protective proteins. The majority of the proteins in cereal grains are storage proteins–in particular, prolamins and globulins. Prolamins are rich in the amino acids proline and glycine but are low in the essential amino acids lysine and tryptophan. Prolamins represent about half of the total protein present in barley, as well as corn, millet, rye, sorghum, and wheat. The primary prolamin in barley is hordein. Barley proteins are low in many of the essential amino acids including lysine, threonine, methionine and histidine.

The protein content of barley varies depending on the variety and growing conditions (Griffey et al., 2010). For example, 6-row cultivars are typically higher in protein than 2-row varieties. Nitrogen fertilization increases the protein content of barley grain, but the relative levels of the essential amino acids decrease.

Inclusion in Poultry Diets Feeding Ground Barley

While corn is typically used in poultry diets in the United States, Canada and many countries in Europe have been using wheat and barley for many years. Of course, the level of use will vary depending on the market prices and local conditions. Wheat and barley are lower in energy than corn, so it is common to add fat to poultry diets based on these grains in order to achieve the high dietary energy levels used in commercial poultry production (Adams, 2001). Such diets can increase the viscosity of the intestinal contents and increase the moisture content of the litter. Wet litter results in increased ammonia levels in the poultry house, as well as an increased incidence of breast blisters and hock burns on meat-type birds.

Nutritionists use nutrient composition tables to formulate least-cost rations that meet the nutrient requirements of animals. The wide variation observed in the energy content of barley, however, is not reflected in table values but needs to be taken into consideration when formulating diets. While many research reports in the literature are contradictory, it is generally recommended that unsupplemented barley should not be used in starter diets, and that the use of barley in poultry diets be restricted to 20%. The use of feed enzymes reduces the need for these restrictions.

The use of feed enzymes in barley-based diets reduces intestinal viscosity, thus improving the feeding value of barley. Enzyme supplementation also reduces the variation in feeding value seen with unsupplemented barley-based diets. Feeding barley cultivars of widely different ß-glucan levels give similar growth performance when supplemented with dietary enzymes. A variety of different feed enzymes are available that have ß-glucanase activity. Using enzymes also improves the litter quality of poultry raised on barley-based diets. Today, near-infrared spectrometry (NIRS) has made it easier to identify which batch of barley would benefit from enzyme supplementation and which would not. Near-infrared spectrometry is a rapid, computerized system that can be used for analyzing feed ingredients. It uses infrared light instead of chemicals for the analysis. The analysis requires that the system be calibrated for the particular ingredient being tested–so may be more expensive for some of the less commonly used ingredients–but has been routinely used in some feed mills for corn, wheat and barley.

Feeding Whole Barley

Feeding whole grain in a complete feed has gained popularity in some regions as it can reduce feed-handling costs by eliminating the need for grinding. When using whole barley to replace all or a part of the grain in the diet, it is necessary to balance grains with the other ingredients so that the whole grain does not dilute the total nutrients consumed by the birds.

Feeding up to 20% whole barley to broilers had no negative effects on growth rate (Biggs and Parsons, 2009). Feeding 35% or more whole barley grain resulted in reduced growth and feed efficiency initially, but this reduced growth rate resulted in lower mortality and instances of leg problems.

Feeding 20% whole barley to turkeys resulted in an early reduction in growth rate (<1% reduction) as well as lower flock mortality and improved skeletal health (Bennett et al., 2002).

Reports of Bennett and Classen (2003) concluded that feeding whole barley (60%) blended with a mash concentrate to laying hens reduced egg production, feed efficiency, and shell quality while increasing feed intake, egg weight and body weight gain. They found this to be contrary to positive results found when choice feeding was used, and speculated that when the grain and concentrate are fed together, the hens can no longer accurately select intakes of whole grains and concentrates that meet their individual nutritional needs.

Summary
  1. Barley grains are lower in energy than corn but higher in protein.
  2. Barley grains contain ß-glucans which adversely affect nutrient availability.
  3. Supplementing barley-based poultry diets with ß-glucanase enzyme increases the level of barley that can be included in the diet without adversely affecting performance. The level of beta-glucanase enzyme required will depend on the age of the bird as well as the barley cultivar used.
  4. Care must be taken when using barley in starter diets. Older birds are better at using barley than young chicks.
  5. Barley grains contain phytate, which makes most of the phosphorus present unavailable. The use of phytase enzymes increases phosphorus availability and reduces the need for supplemental phosphorus. This results in increased phosphorus utilization, thus reducing fecal loss of phosphorus and consequently less damage to the environment.
Byproducts Brewer's Dried Grains

Brewer's dried grains are a byproduct of making wort or beer. They are also sometimes referred to as spent grain. They include cellulose and hemicellulose as well as the protein remaining after barley has been malted to releases its sugar for brewing. Sugars and starches in the original grain are removed during the brewing process so that the remaining spent grains are higher in protein but lower in energy than the original grain. The crude protein, oil and crude fiber content of the spent grains are about twice that of the original grain. The use of brewer's dried grains in starter diets should be less than 10%. Up to 30% can be used in grower diets, although the feed efficiency will be reduced. The restriction is due to the high fiber content of brewer's dried grains (Ademosun, 1973).

Malt Sprouts

Malt sprouts are obtained from malted barley by removal of the rootlets and sprouts. They may also include some of the malt hulls, other parts of the malt, and foreign material. They must contain a minimum of 24% crude protein.

Nutrient content of malt sprouts (Batal and Dale, 2010)

  • Dry matter: 92%
  • Metabolizable energy: 1410 kcal/kg (640 kcal/lb)
  • Crude protein: 25%
    • Methionine: 0.32%
    • Cysteine: 0.23%
    • Lysine: 1.10%
    • Tryptophan: 0.41%
    • Threonine: N/A
  • Crude fat: 1.2%
  • Crude fiber: 15.0%
  • Ash: 7.0%
    • Calcium: 0.20%
    • Total phosphorus: 0.70%
    • Non-phytate phosphorus: none
References and Citations
  • Adams, C. A. 2001. Interactions of feed enzymes and antibiotic growth promoters on broiler performance [Online]. Cahiers Options Méditerranéennes 54: 71–74. Available at: http://ressources.ciheam.org/om/pdf/c54/01600013.pdf(verified 10 July 2013)
  • Ademosun, A. A. 1973. Evaluation of brewer's dried grains in the diets of growing chickens. British Poultry Science 14(5): 463–468. (Available for purchase online at: http://dx.doi.org/10.1080/00071667308416053) (verified 10 July 2013)
  • Ankrah, N. O., G. L. Campbell, R. T. Tyler, B. G. Rossnagel, and S.R.T. Sohansanj. 1999. Hydrothermal and beta-glucanase effects on the nutritional and physical properties of starch in normal and waxy hull-less barley. Animal Feed Science and Technology 81: 205–219. (Available for purchase online at: http://www.animalfeedscience.com/article/PIIS037784019900084X/abstract) (verified 10 July 2013)
  • Bartnick, M., and I. Szafrańska. 1987. Changes in phytate content and phytase activity during germination of some cereals. Journal of Cereal Science 5: 23–28. (Available for purchase online at: http://dx.doi.org/10.1016/S0733-5210(87)80005-X) (verified 10 July 2013)
  • Batal, A., and N. Dale. 2010. Feedstuffs Ingredient Analysis Table: 2011 edition. Feedstuffs.
  • Bennett, C. D., H. L. Classen, K. Schwean, and C. Riddell. 2002. Influence of whole barley and grit on live performance and health of turkey toms. Poultry Science 81: 1850–1855. (Available online at: http://ps.fass.org/content/81/12/1850.short) (verified 11 July 2013)
  • Bennett, C. D., and H. L. Classen. 2003. Performance of two strains of laying hens fed ground and whole barley with and without access to insoluble grit. Poultry Science 82: 147–149. (Available online at: http://ps.fass.org/content/82/1/147.short) (verified 11 July 2013)
  • Biggs, P. and C. M. Parsons. 2009. The effects of whole grains on nutrient digestibilities, growth performance and cecal short-chain fatty acid concentrations in young chicks fed ground corn-soybean meal diets. Poultry Science 88: 1893–1905. (Available online at: http://ps.fass.org/content/88/9/1893.short) (verified 11 July 2013)
  • Brown, B. D. 2003. Rotation factors and field selection. p. 8. In L. D. Robertson and J. C. Stark (eds.) Idaho Spring Barley Production Guide. BUL 742. University of Idaho, College of Agriculture and Life Sciences, Moscow. (Available online at: http://www.cals.uidaho.edu/edcomm/pdf/BUL/BUL0742.pdf) (verified 11 July 2013)
  • Griffey, C., W. Brooks, M. Kurantz, W. Thomason, F. Taylor, D. Obert, R. Moreau, R. Flores, M. Sohn, and K. Hicks. 2010. Grain composition of Virginia winter barley and implications for use in feed, food and biofuels production. Journal of Cereal Science 51: 41–49. (Available for purchase online at: http://dx.doi.org/10.1016/j.jcs.2009.09.004) (verified 11 July 2013)
  • Jeroch, H. and S. Danicke. 1995. Barley in poultry feeding: A review. World's Poultry Science Journal 51:271–291. (Available for purchase online at: http://dx.doi.org/10.1079/WPS19950019) (verified 11 July 2013)
  • Knudsen, K.E.B. 1997. Carbohydrate and lignin content of plant materials used in animal feeding. Animal Feed Science and Technology 67: 319–338. (Available for purchase online at: http://dx.doi.org/10.1016/S0377-8401(97)00009-6) (verified 10 July 2013)
  • Linares, L. B., J. N. Broomhead, E. A. Guaiume, D. R. Ledoux, T. L. Veum, and V. Raboy. 2007. Effects of low phytate barley (Hordeum vulgare L.) on zinc utilization in young broiler chicks. Poultry Science 86:299–308. (Available online at: http://ps.fass.org/content/86/2/299.abstract) (verified 11 July 2013)
  • Salarmoini, M., G. L. Campbell, B. G. Rossnagel, and V. Raboy. 2008. Nutrient retention and growth performance of chicks given low-phytate conventional or hull-less barleys. British Poultry Science 49: 321–328. (Available online at: http://dx.doi.org/10.1080/00071660802136890) (verified 11 July 2013)
  • Shewry, P. R. and A. S. Tatham. 1990. The prolamin storage proteins of cereal seeds: Structure and evolution. Biochemistry Journal 267:1–12. (Available online at: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1131235/) (verified 11 July 2013)
  • Tester, R. F., and W. R. Morrison. 1992. Swelling and gelatinization of cereal starches III. Some properties of waxy and normal non-waxy barley starches. Cereal Chemistry 69: 654–658. (Available online at: http://www.aaccnet.org/publications/cc/backissues/1992/Documents/CC1992a158.html) (verified 11 July 2013)
  • Weremko, D., H. Fandrejewski, T. Zebrowska, I.K., J.H. Kim and W.T. Cho. 1997. Bioavailability of phosphorus in feeds of plant origin for pigs - A review. Asian-Australian Journal of Animal Science 10: 551–566. (Available online at: http://www.ajas.info/journal/view.php?number=19220 (verified 11 July 2013)

 

This is an eOrganic article and was reviewed for compliance with National Organic Program regulations by members of the eOrganic community. Always check with your organic certification agency before adopting new practices or using new materials. For more information, refer to eOrganic's articles on organic certification.

eOrganic 8093

Resources for Organic Certification of Research Sites and Facilities

New/updated @ eXtension - Wed, 05/22/2019 - 08:23

eOrganic author:

Jim Riddle, University of Minnesota

Websites
  • Agricultural Marketing Service - National Organic Program [Online]. Agricultural Marketing Service United States Department of Agriculture. Washington, DC. Available at: http://www.ams.usda.gov/nop (verified 16 March 2010).
  • Midwest Organic and Sustainable Education Service [Online]. Spring Valley, WI. Available at: http://www.mosesorganic.org (verified 16 March 2010).
  • ATTRA - National Sustainable Agriculture Information Service: organic farming, sustainable ag, publications, newsletters [Online]. National Center for Appropriate Technology (NCAT). Fayetteville, AR. Available at: http://www.attra.org (verified 16 March 2010).
  • USDA ERS- Organic Agriculture [Online]. United States Department of Agriculture Economic Research Service. Washington, DC. Available at: http://www.ers.usda.gov/topics/natural-resources-environment/organic-agr... (verified 24 August 2015).
  • Organic Farming Research Foundation -- Home [Online]. Organic Farming Research Foundation. Santa Cruz, CA. Available at: http://ofrf.org/ (verified 16 March 2010).
  • OMRI - Organic Material Review Institute [Online]. Eugene, OR. Available at: http://www.omri.org/ (verified 16 March 2010).
  • Organic Trade Association [Online]. Greenfield, MA. Available at: http://www.ota.com/index.html (verified 17 Dec 2008).
  • New Farm For Farmers | Rodale Institute [Online]. Rodale Institute. Kutztown, PA. Available at: http://www.rodaleinstitute.org/new_farm (verified 16 March 2010).
  • The Organic Center [Online]. Washington DC. Available at: http://www.organic-center.org/ (verified 5 Nov 2015).
  • How to Go Organic - Resource for transitioning to organic [Online]. The Organic Trade Association. Greenfield, MA. Available at: http://www.howtogoorganic.com/ (verified 16 March 2010).
  • Organic Agriculture: Organic Agriculture Home [Online]. Food and Agriculture Organization of the United Nations. Rome, Italy. Available at: http://www.fao.org/organicag/en/ (verified 16 March 2010).

 

This is an eOrganic article and was reviewed for compliance with National Organic Program regulations by members of the eOrganic community. Always check with your organic certification agency before adopting new practices or using new materials. For more information, refer to eOrganic's articles on organic certification.

eOrganic 727

Scouting for Vegetable and Fruit Pests on Organic Farms

New/updated @ eXtension - Tue, 05/21/2019 - 13:42


Resources Mentioned in the Webinar

Fruit Crop Pest Models - WSU Decision Aid System

Garden Insects of North America - W. Cranshaw

Natural Enemies Handbook - M.L Flint, S. Dreistadt

Northeast Vegetable and Strawberry Pest Identification Guide-University of Massachussetts

North Carolina State University: Insect and Related Pests of Vegetables

Pacific Northwest Insect Management Handbook

Integrated Crop and Pest Management Guidelines for Commercial Vegetable Production. Cornell University

Pests of the Garden and Small Farm, M.L. Flint

Pests of the West - W. Cranshaw

University of California IPM Online: Natural Enemies Gallery

USPEST.ORG IPM Pest and Plant Disease Models and Forecasting

About the Webinar

Crop consultant, Doug O’Brien, and organic farmer, Helen Atthowe, share their pest monitoring and decision making tips and short cuts. Learn how to look for insect, disease, and crop quality problems on organic vegetable and fruit farms. We will also touch on some ideas about how to maintain records that will help you better understand pest problems and what to do about them.

This webinar was funded by Western SARE project SW09-031: Bean Mold Management Tools and Rotational Systems Management.

Handout of the slides from this webinar

About the Presenters

Helen Atthowe has been farming on her own and consulting for other organic vegetable and fruit farms for 25 years. She was a horticulture extension agent for 15 years and owned and operated Biodesign Farm (30 acre diverse organic fruit and vegetable farm) in western Montana for 17 years. She recently spent 6 months as a consulting vegetable grower for a 2000 acre organic vegetable and fruit farm in northern Colorado with a 5000 member CSA.

Doug O'Brien currently owns and operates Doug O’Brien Agricultural Consulting, providing on-site technical advice, field monitoring, and research for clients involved in fresh produce growing, harvesting, cooling and marketing. He is an adjunct professor at Cabrillo College, in Santa Cruz, CA and teaches classes in organic farming. Previously, Doug was a co-owner of an organic produce brokerage company, a crop production manager, and an assistant farm advisor.

Find all upcoming and archived eOrganic webinars at http://www.extension.org/pages/25242 

 

This is an eOrganic article and was reviewed for compliance with National Organic Program regulations by members of the eOrganic community. Always check with your organic certification agency before adopting new practices or using new materials. For more information, refer to eOrganic's articles on organic certification.

eOrganic 8951

New Clues to Control Spread of Common Parasite

USDA Agricultural Research Service - Wed, 08/24/2016 - 05:50
New Clues to Control Spread of Common Parasite / August 24, 2016 / News from the USDA Agricultural Research Service
Read the magazine story to find out more

ARS microbiologist Jitender Dubey examines a Toxoplasma gondii specimen with a compound microscope. Link to photo information
ARS microbiologist Jitender Dubey examines a Toxoplasma gondii specimen with a compound microscope. Click the image for more information about it.


For further reading

New Clues to Control Spread of Common Parasite

By Rosalie Marion Bliss
August 24, 2016

U.S. Department of Agriculture (USDA) scientists and colleagues have provided new clues about the virulence of Toxoplasma gondii—the most widespread parasite in the world. The study described mechanisms involving genetic expression that help a mild-mannered T. gondii strain turn aggressive.

For the study, a consortium of international researchers, including Agricultural Research Service (ARS) zoologist Benjamin Rosenthal and parasitologist Jitender Dubey, contributed strains of T. gondii from more than a dozen countries spanning the Americas, Europe, Africa and Asia. Both researchers are with the ARS Animal Parasitic Diseases Laboratory in Beltsville, Maryland.

The team conducted a genomic analysis on each of 62 strains and identified several types of proteins, called "secretory pathogenicity determinants" (SPDs), that thwart the hosts' immunity. Secreting SPDs enables the parasite to influence and hinder the host's defenses. These proteins enhance the parasite's survival and, as a result, induce more or less severe disease in hosts.

T. gondii infection can occur when humans and other animals are exposed to contaminated soil, water, food, or litterboxes. Infection can also take place when people consume undercooked meat containing T. gondii. Prevention is key.

The findings are helping researchers to identify the genetic basis for differences among strains of T. gondii, from mild-mannered strains found in U.S. farmlands to more virulent strains found in the jungles of Brazil and French Guyana. The researchers found that T. gondii strains could become more aggressive through environmental adaptation.

The study results provide valuable information about a subset of regulatory genes that enable the parasite to infect animals and humans. The findings will help researchers develop new treatments and methods to check the parasite's ability to transmit.

The study appeared in the January 2016 issue of Nature Communications. Read more about this work in the August 2016 issue of AgResearch.

ARS is USDA's chief in-house scientific research agency.

Categories: USDA

Berenbaum Discusses Insect-Plant Interaction During ARS Sterling B. Hendricks Memorial Lecture

USDA Agricultural Research Service - Tue, 08/23/2016 - 08:03
Berenbaum Discusses Insect-Plant Interaction During ARS Sterling B. Hendricks Memorial Lecture / August 23, 2016 / News from the USDA Agricultural Research Service

May Berenbaum.
May R. Berenbaum delivers the 2016 ARS Sterling B. Hendricks Memorial Lecture at the American Chemical Society Meeting. Click the image for more information about it.


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Berenbaum Discusses Insect-Plant Interaction During ARS Sterling B. Hendricks Memorial Lecture

By Kim Kaplan
August 23, 2016

Dr. May R. Berenbaum shed light on the relationship between insects and plants during today's 2016 Agricultural Research Service (ARS) Sterling B. Hendricks Memorial Lecture. Her talk was presented at the American Chemical Society (ACS) Fall Meeting in Philadelphia.

Internationally recognized for her research about interactions between insects and their host plants, Berenbaum through her work has fundamentally changed the understanding of the relationship between insects and the plants they eat. That research has created the basis for the theory of coevolution. She has described the "arms race" between plants and the insects that feed on them. Her work has provided a strong evolutionary outline for insects' resistance to insecticides.

Additionally, Berenbaum provides leadership in a number of today's important insect-related issues like pollinator declines, insects and GM crops, invasive species, pesticides and resistance, and insect conservation. She is a prominent researcher of Colony Collapse Disorder and other stresses involved in the colony losses beekeepers face.

Since 1992, Dr. Berenbaum has been head of the Department of Entomology at the University of Illinois at Urbana-Champaign. She also has held the endowed Swanlund Chair of Entomology there since 1996.

Dr. Berenbaum received this Nation's highest scientific honor, the National Medal of Science, in 2014.

ARS established this lectureship in 1981 to honor the memory of Sterling B. Hendricks and to recognize scientists for outstanding contributions to the chemical science of agriculture. Dr. Hendricks contributed to many diverse scientific disciplines, including plant physiology, soil science, mineralogy, agronomy, geology and chemistry.

ARS is the U.S. Department of Agriculture's chief in-house scientific research agency.

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Extracting Heavy Metals with Vegetable Oils

USDA Agricultural Research Service - Wed, 08/17/2016 - 05:23
Extracting Heavy Metals with Vegetable Oils / August 17, 2016 / News from the USDA Agricultural Research Service
Read the magazine story to find out more.

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In the vial, the oil droplet's red color shows that it absorbed metals from the water/metal solution. Click the image for more information about it.


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Extracting Heavy Metals with Vegetable Oils

By Sandra Avant
August 17, 2016

A new process patented by the U.S. Department of Agriculture (USDA) uses vegetable oils to remove metals from liquids, solids and gases.

Scientists at the Agricultural Research Service (ARS) National Center for Agricultural Utilization Research (NCAUR) in Peoria, Illinois, created a chemical process to separate heavy metal ions such as silver from water by using "functionalized" vegetable oils.

The method is simple, according to Rex Murray, research leader at NCAUR's Bio-Oils Research Unit. When functionalized oil is mixed with water contaminated with toxic heavy metals, certain atoms in the oil bind to the heavy metals and pull them from the water. This allows clean water to separate from the heavy-metal-containing oil, allowing for removal from the environment.

Water contaminated with heavy metals can pose environmental concerns and serious health problems. Using vegetable oils to clean up heavy metals is environmentally friendly, because vegetable oils are biodegradable, nontoxic, and are derived from renewable resources.

In the past, NCAUR scientists have found other beneficial uses for vegetable oils, which include use as inks, lubricants and diesel fuel.

ARS is the U.S. Department of Agriculture's chief in-house scientific research agency.

Read more about this research in the August 2016 AgResearch magazine.

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Watkins Delivers Morrison Memorial Lecture at ASHS Conference

USDA Agricultural Research Service - Mon, 08/08/2016 - 06:48
Watkins Delivers Morrison Memorial Lecture at ASHS Conference / August 8, 2016 / News from the USDA Agricultural Research Service
Christopher B. Watkins
2016 ARS B.Y. Morrison Memorial Lecturer Christopher B. Watkins.

Golden Delicious, Gala, Granny Smith, and Red Delicious apples. Link to photo information
Consumers now have access to apples like Golden Delicious, Gala, Granny Smith, and Red Delicious all year round, thanks in part to new storage technologies and management strategies. Click the image for more information about it.


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Watkins Delivers Morrison Memorial Lecture at ASHS Conference

By Kim Kaplan
August 8, 2016

"New Technologies for Storage of Horticultural Products—There Is More to Adoption Than Availability" is the title of Christopher B. Watkins' 2016 ARS B.Y. Morrison Memorial Lecture, which he delivered today at the American Society for Horticultural Science (ASHS) annual conference in Atlanta.

Watkins has contributed to the success of fruit and floral industries around the world as a leader in postharvest science and outreach. His research about controlled atmosphere biology, edible quality of fruit management, and chilling injury prevention is used across varieties and cultivars, across species, and across production areas.

In particular, Watkins has remained at the forefront of addressing significant apple industry issues by applying new developments in postharvest technologies. His research about the artificial ripening regulator 1-methylcyclopropene (1-MCP) is instrumental in the understanding of apple ethylene biology, both from a scientific standpoint and from industry's applied perspective and practical need to control ripening.

Within the floral industry, 1-MCP is used to preserve the freshness of ornamental plants and flowers. Growers, packers and shippers use 1-MCP to maintain the quality of fruits and vegetables as diverse as kiwifruit, tomatoes, plums, persimmons, avocados and melons.

By implementing the postharvest practices developed by Dr. Watkins, the apple industry has greatly improved the quality of fruit delivered to consumers while reducing or eliminating the use of synthetic postharvest chemicals. His research with 'Honeycrisp' apples identified a postharvest strategy that has largely eliminated postharvest chilling injury, which has allowed this variety to achieve a profitability unprecedented in the apple industry.

Watkins is director of Cornell University Cooperative Extension as well as a professor of postharvest science and associate dean of the Colleges of Agriculture and Life Sciences at Cornell.

The Agricultural Research Service (ARS) established this memorial lectureship in 1968 to honor the memory of Benjamin Y. Morrison (1891-1966) and to recognize scientists who have made outstanding contributions to horticulture and other environmental sciences, to encourage the use of these sciences, and to stress the urgency of preserving and enhancing natural beauty. Morrison was a pioneer in horticulture and the first director of ARS's U.S. National Arboretum in Washington, DC. A scientist, landscape architect, plant explorer, author and lecturer, Morrison advanced the science of botany in the United States and fostered broad international exchange of ornamental plants.

ARS is the U.S. Department of Agriculture's chief in-house scientific research agency.

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