Contrary to conventional wisdom, grazing low numbers of cattle on cover crops does not compact the soil or cut down on the organic matter added, according to new ARS research. Click the image for more information about it.
- USDA Scientists Say Mix-and-Match Cover Cropping Can Optimize Organic Production
- The Right Way to Roll Rye
- Grazing of Cattle Pastures Can Improve Soil Quality
By Dennis O’Brien
February 11, 2015
A U.S. Department of Agriculture (USDA) scientist in North Carolina has found a way to encourage more growers to use cover crops in the Southeastern United States—allow cattle to graze on them.
Cover crops reduce soil erosion, boost organic matter, keep more moisture in soil and sequester carbon in the soil so less of it is released as a greenhouse gas.
Conventional wisdom holds that if cattle were allowed to graze on cover crops they would eat up and remove the nitrogen and carbon otherwise left on the soil in the cover crop plant residue. Allowing cattle to tread on the soil also could compact it, preventing air and water from passing through the soil to reach plant roots.
Alan Franzluebbers, an ecologist with the Agricultural Research Service (ARS) Plant Science Research Unit in Raleigh, conducted a 7-year study to see if grazing on cover crops affects the health of soils typical in the Piedmont region. ARS is USDA’s principal intramural scientific research agency, and this research supports the USDA priority of promoting sustainable agriculture.
Franzluebbers and his colleagues grew winter or summer grains and used cover crops for both in the off-season. They also compared no-till versus tilling, and grazing versus no grazing. Cow/calf pairs were allowed to graze at a rate of one pair per 4 acres.
The researchers took periodic samples of the surface foot of soil. The study was the first in the region to analyze the practices for such an extensive period.
The results showed that the relatively low-level of grazing did not significantly affect the amount of organic matter in soil and did not compact the soil. They also showed that cover crops provided high quality forage and that the organic matter lost by allowing cattle to graze on cover crops was likely made up in the organic material supplied as manure. As in previous studies, they also found that no-till soils generally contained more carbon and nitrogen than conventional till soils.Read more about this research in the February 2015 issue of Agricultural Research magazine.
By Kim Kaplan
February 10, 2015
New nutrition and health findings in the latest issue of the Agricultural Research Service's (ARS) Food and Nutrition Research Briefs include research showing that about 2 percent of the cattle grazing in a pasture or eating high-energy rations in a feedlot pen, on average, may be "supershedders"—shedding high levels of pathogenic organisms such as Escherichia coli O157:H7 in their manure.
It can be found at http://www.ars.usda.gov/is/np/fnrb/fnrb0215.htm
The popular online newsletter reports discoveries from researchers at ARS laboratories nationwide.
Among other findings, the current issue reports —
• The latest update of the U.S. Department of Agriculture (USDA) National Nutrient Database for Standard Reference, Release 27, is now available including new and updated food-nutrient profiles and a reorganized Internet "dashboard" that users see after launching the online version of the database.
• The Ossabaw pig, a heritage breed, has been proven to be an excellent model for human obesity-related research and for studying metabolic effects induced by a high-fat diet.
• A new, more precise analytical method has been developed for detecting and measuring concentrations of phytochemicals called "polyphenols" in fruit and vegetables.
ARS Food and Nutrition Research Briefs is offered with color photos and illustrations on the Web. And by clicking the "subscribe" link on the newsletter's home page, readers can sign up for either of two e-mail options: They can receive the full text of the newsletter by e-mail or simply an advisory that a new issue has been posted to the Web.
ARS is the USDA's chief intramural scientific research agency.
- Sorghum Eyed as a Southern Bioenergy Crop
- Tapping Sorghum's Potential for Cold Tolerance
- Tapping Into Sorghum's Weed Fighting Capabilities to Give Growers More Options
By Sharon Durham
February 6, 2015
A new sorghum plant developed by U.S. Department of Agriculture (USDA) scientists can produce more seeds than conventional varieties currently grown by farmers.
Agricultural Research Service (ARS) molecular biologist Zhanguo Xin and plant geneticist Gloria Burow at the Plant Stress and Germplasm Research Unit, along with lab director and research leader John Burke, at the ARS Cropping Systems Research Laboratory in Lubbock, Texas, developed a mutant sorghum plant that produces 30 to 40 percent more seeds.
ARS is the USDA’s chief intramural scientific research agency.
The researchers developed the higher yielding sorghum by taking advantage of a plant part called a “spikelet.” A spikelet is a cluster of florets within the panicle, a type of flower cluster found in some other grasses, such as millet or rye. Sorghum produces two types of spikelets: the sessile spikelets and the pedicellate spikelets. Normally, only the sessile spikelets are fertile, but the ARS scientists developed a sorghum plant that produces seeds in both types of spikelets.
The team developed the productive sorghum line by inducing a mutation in sorghum plants that allowed infertile spikelets to grow and produce seed, according to Xin. An induced mutation is produced by treatment with a mutagen, like radiation or a chemical agent such as ethyl methane sulfonate. The mutation resulted in an overall increase in size and volume (length, width, and thickness) of the sorghum panicle.
All of the spikelets of the new sorghum plant develop into flowers and produce mature seeds, thereby significantly increasing seed production and yield in comparison to conventional sorghum. The mutants may be crossed with other sorghum lines, particularly elite large-seeded lines, to improve grain yield in sorghum and other related species. The mutation in the sorghum line we developed is stable and can be passed on to other sorghum lines through breeding, according to Xin.
A sample of at least 2,500 seeds of the new multiseeded sorghum has been deposited with the American Type Culture Collection for future research.
Read more about this research in the February 2015 issue of Agricultural Research magazine.
New research by ARS scientists and their Brazilian collaborators has found that two bacterial pathogens are more common in honey bees than previously thought. Click the image for more information about it.
- Survey Reports Fewer Winter Honey Bee Losses
- Disinfecting Honey Comb with Ozone
- Bees Exposed to Fungicide More Vulnerable to Nosema Parasite
By Dennis O'Brien
February 5, 2015
U.S. Department of Agriculture (USDA) scientists in Maryland and their colleagues have found that two pathogens causing mysterious honey bee ailments are a problem not just in the spring, but they might pose a threat year-round. Ryan Schwarz and Jay Evans, entomologists with the Agricultural Research Service (ARS), have shown that two species of bacteria, Spiroplasma melliferum and S. apis, are more common than previously thought and infect honey bees in places as diverse as Brazil and Beltsville, Maryland.
ARS is USDA's principal intramural scientific research agency, and this research supports the USDA priority of promoting sustainable agriculture.
Both pathogens were discovered more than 30 years ago, but scientists are still unsure if they are factors in colony collapse disorder or major causes of other bee mortalities.
Schwarz and Evans, based at the ARS Bee Research Laboratory in Beltsville, and their colleagues at the Brazilian Honey Bee Laboratory in SÃ£o Paulo analyzed the DNA of bees in Beltsville and Brazil between 2011 and 2013. Bees were collected from 11 states in Brazil and 2 areas in Beltsville. Schwarz had recently developed genetic markers that allow researchers to distinguish S. apis from other bacteria in bees. They used those markers and another recently developed set of S. melliferum markers to determine the year-round prevalence of the two pathogens.
As expected, the researchers found that both pathogens were prevalent in the spring. But they also found that they were common at other times of the year as well and that their prevalence rates varied depending on the location. In Beltsville, the pathogens were more prevalent in the spring, while in Brazil they were more prevalent in the fall. The results also showed that S. melliferum was the more prevalent of the two and that the presence of one pathogen made bees more susceptible to the other.
Schwarz says the results should help beekeepers and scientists monitor the health of honey bees by raising awareness about the year-round nature of the threat the pathogens might pose. Equipped with the new genetic markers developed for the pathogens, scientists also will be better able to screen bee colonies for the pathogens.
Read more about this research in the February 2015 issue of Agricultural Research magazine.
Planting winter rye in no-till corn and soybean fields in the Midwest could reduce nitrogen runoff by as much as 43 percent, according to a new ARS field-scale computer model. Click the image for more information about it.
- Using Local Lakes to Safeguard Regional Water Quality
- Prairie Restoration Also Helps Restore Water Quality
- Tools That Will Help Reduce Nitrogen Pollution
By Rosalie Marion Bliss
February 4, 2015
Using cover crops in between corn and soybean crop production in the Midwest could significantly reduce nitrate load runoff via subsurface drains, according to U.S. Department of Agriculture (USDA) scientists. This reduction could support national efforts to reduce nitrate loads and protect water quality in the Gulf of Mexico.
Excess water laden with nitrates in many Midwestern crop fields drains into subsurface perforated pipes and then flows into surface streams and rivers. The nutrient-rich field drainage reaches the Gulf of Mexico and supports algal blooms that lower water oxygen levels and contribute to developing a devastating “dead zone.”
Agricultural Research Service (ARS) scientists Rob Malone, Tom Kaspar, and Dan Jaynes are using the Root Zone Water Quality Model to assess how using winter rye cover crops in corn–soybean rotations could mitigate nitrate loads in the field-drainage water. The researchers are with the ARS National Laboratory for Agriculture and the Environment in Ames, Iowa. The ARS field-scale computer model was developed to simulate plant growth and the movement of water, nutrients and chemicals within and around the root zones of agricultural crops. ARS is USDA's chief intramural scientific research agency, and this research supports the USDA goal of promoting agricultural sustainability.
The researchers ran the model simulation for several different planting scenarios at 41 sites across the Midwest from 1961 to 2005. Their results indicated that winter rye crops seeded in no-till corn–soybean systems when the cash crops were mature have the potential to reduce annual nitrate loss in field drainage by about 43 percent, or by 18 pounds per acre.
Malone and his colleagues used their findings in a larger regional simulation of nitrate losses from drained fields located within the Mississippi River Watershed. Results indicated that producers could introduce winter rye cover cropping on around 30 to 80 percent of the land used for corn and soybean production, and that the cover crop systems could potentially reduce nitrate loadings in the Mississippi River by approximately 20 percent.
Read more about this research in the January 2015 issue of Agricultural Research magazine.
Researchers are shifting the way they look at the complex ecosystems of semi-arid dry lands; these perspectives are highlighted in a special issue of Frontiers in Ecology and the Environment. Click image for high resolution verison.
- Climate Changes Help Grass Come Back to U.S. Rangelands
- New Maps Show the Way for Rangeland Management
- Developing Strategies in a Desert Watershed that Sustain Regional Water Supplies
By Rosalie Marion Bliss
February 2, 2015
Vast acreage of dry lands may evoke images of desolate, scorched, uninhabitable desert. But the arid and semi-arid dry lands of about half of both the United States' and the world's land surfaces actually are complex ecosystems made up variously of grasses, shrubs, agriculture, and even urban-dwellers. Now, ecological education is taking a step forward with the publication of seven scientific papers on new paradigms for dryland ecology and management. The papers are in a special issue of the journal Frontiers in Ecology and the Environment, now available to the public via open access [http://www.esajournals.org/toc/fron/13/1].
In the special issues, the articles' authors broaden the traditional framework for studying dry lands based on desertification to provide a comprehensive and improved approach for understanding, managing and predicting complex dryland dynamics. They provide new perspectives for the dynamics of how water and wind move material across dry lands in the context of historic environmental conditions, called "legacies," current climate extremes, and changing patterns of land use. The new framework can be used to assess dryland ecosystem services, inform land-management decisions, and improve the ecological literacy of future generations living on dry lands.
The special issue was organized by ecologist Debra Peters, who is the U.S. Department of Agriculture's (USDA) Senior Advisor for Earth Observations and Lead Principal Investigator of the Jornada Basin Long Term Ecological Research (LTER) Project. LTER is funded by the National Science Foundation (NSF) and based at the Jornada Experimental Range ("Jornada") in Las Cruces, New Mexico. Peters' research unit is part of the Agricultural Research Service (ARS)—USDA's principal intramural scientific research agency.
The articles were authored by ARS Long Term Agro-ecosystem Research (LTAR) Unit scientists at Jornada, including Peters and unit head Kris Havstad, and their colleagues at New Mexico State University (NMSU), Arizona State University, the University of Arizona, the U.S. Geological Survey, the University of California at Los Angeles, and the Asombro Institute for Science Education. The guest editorial was contributed by Ann Bartuska, USDA Deputy Under Secretary for Research, Education and Economics.
The special issue represents collaborations among partners at, and funding by, the USDA-ARS LTAR program, the NSF's LTER Program, and NMSU.
The special issue "Emerging Perspectives and Shifting Paradigms in Water-Limited Systems" was published February 2, 2015, in Frontiers in Ecology and the Environment. These findings support the USDA priority of responding to climate change.
- Pampering Anjou Pears: ARS Studies Explore Storage Ideas
- Enhanced Lure Proves Irresistible to Orchard Pest
By Sharon Durham
January 30, 2015
A new pear cultivar, 'Gem', has been released jointly by the U.S. Department of Agriculture (USDA), Oregon State University, Michigan State University and Clemson University. Gem is ideal for the fresh market, combining high yields with excellent appearance, fruit quality and long storage potential. The new cultivar is resistant to fire blight and isn't prone to brown discoloration, called "superficial scald," that affects some pear varieties.
Horticulturist Richard Bell, at the Agricultural Research Service's (ARS) Appalachian Fruit Research Station in Kearneysville, West Virginia, and his colleagues describe Gem in the March 2014 issue of HortScience.
Gem requires at least 3 weeks of cold storage before normal fruit softening, but it will last for at least 28 weeks in cold storage without core breakdown or superficial scald. The fruit can also be eaten immediately after harvest without softening, as it has a crisp, juicy texture. Its flavor is sweet and mildly aromatic. When compared to Bartlett, a popular pear variety, sensory panelists rated Gem similar in appearance, flavor and purchase intent.
The original seedling tree of Gem was from a cross of 'Sheldon' and US62563-004 made in 1970. Bell selected Gem in 1981 from the seedling orchard at the ARS Henry A. Wallace Beltsville Agricultural Research Center in Beltsville, Maryland.
The source of Gem's fire blight resistance comes from the cultivar 'Barseck'. Subsequently, Gem was evaluated for fruit quality, fire blight resistance and productivity in replicated trials at the Kearneysville location and at research centers at Washington State University, Oregon State University, Michigan State University, Cornell University and Clemson University.
Gem is recommended as a fresh-market pear for both commercial and home orchards. While budwood of Gem is limited, genetic material of this release will be deposited in the National Plant Germplasm System, where it will be available for research purposes, including development and commercialization of the new cultivar.
ARS is the USDA's chief intramural scientific research agency, and this research supports the USDA priority of promoting international food security.
- French Fries' Oil Content: It's Lower with Infrared Heat
- Infrared Based Approach Explored for Keeping Almonds Safe to Eat
By Sandra Avant
January 29, 2015
Peeled tomatoes make a tasty, versatile and time-saving ingredient for hearty winter stews, homemade soups or classic casseroles. In experiments with more than 6,000 field-ripened Roma-style (sometimes called “plum”) tomatoes, U.S. Department of Agriculture (USDA) scientist Zhongli Pan and his industry and university colleagues have shown that using infrared heating to simplify removal of the tomatoes’ tight-fitting peels may offer advantages over other peeling technologies.
The researchers have demonstrated, for example, that infrared-based peeling is mostly waterless. That’s a benefit for canneries in sometimes-drought-stricken California, the state that produces the majority of the nation’s processing tomatoes.
Not only could the technique cut the cost of bringing water to canneries, but it might also reduce the expense of recycling the water or properly disposing of it.
Disposal is of particular concern to processors who use sodium hydroxide or potassium hydroxide to peel tomatoes. These substances can increase the cost of treating factory wastewater, according to Pan.
What’s more, the infrared process may help reduce wasteful “overpeeling” of tomatoes that can occur when too many layers of tomato are inadvertently removed along with the peel. In a study published in the journal Innovative Food Science and Emerging Technologies in 2014, Pan and co-researchers showed that peel-related loss was about 8 to 13 percent with infrared heating as compared to about 13 to 16 percent with sodium hydroxide-based peeling.
The infrared studies are apparently the most extensive to date of their kind for environmentally sound peeling of tomatoes.
Pan, who is based at the Agricultural Research Service (ARS) Western Regional Research Center in Albany, California, and coworkers Tara McHugh, research leader and research food technologist at the Albany center, Carlos Masareje of Precision Canning Equipment, and James Valenti-Jordan of Del Monte Foods recently received a patent for the peeling process. Pan hopes to have the system ramped up to match cannery operating speeds by 2016.This technology, highlighted in the January 2015 issue of Agricultural Research magazine, supports the USDA priority of reducing food waste. ARS is the USDA’s principal intramural scientific research agency.
This image shows the algal bloom (green) covering the entire western basin and beginning to expand into the central basin. ARS scientists are monitoring phosphorus discharge from farms in surface runoff and tile drainage, so they can recommend best management practices to farmers. Click the image for more information about it.
- User-Friendly Program Updates Phosphorus Management
- Prairie Restoration Also Helps Restore Water Quality
- Ditching Phosphorus Runoff
By Dennis O'Brien
January 28, 2015
When runoff flows from farm fields into the Lake Erie Basin, phosphorus in that runoff contributes to the algal blooms that can contaminate drinking water supplies. Surface runoff is generally considered to be the most significant source of that phosphorus. But studies by two U.S. Department of Agriculture (USDA) scientists show that underground tile drains—commonly used by Midwestern farmers to drain excess water from crop fields—are also major contributors of phosphorus.
Since 2008, Doug Smith, a soil scientist at the Agricultural Research Service (ARS) Grassland, Soil and Water Research Laboratory in Temple, Texas, has been monitoring phosphorus in surface runoff and tile drainage from farm fields in the St. Joseph River Watershed in northeast Indiana, which is part of the larger Lake Erie Watershed. Between 2008 and 2013, he found that 49 percent of dissolved phosphorus and 48 percent of total phosphorus in the watershed was discharged via tile drains.
From 2005 to 2012, Kevin King, an agricultural engineer at the ARS Soil Drainage Research Unit in Columbus, Ohio, monitored phosphorus levels in the discharge from six tile drains and the outlet of a headwater watershed in central Ohio. He found that tile drains contributed 47 percent of the phosphorus discharge.
Farmers in the region are generally careful to apply only as much fertilizer as needed, and King's measurements indicated that only around 2 percent of that phosphorus was lost through runoff. But phosphorus concentrations in the tile drainage and the watershed discharge often exceed concentrations recommended for preventing algal blooms, the researchers say. King's team concluded that reducing phosphorus losses will require practices that mitigate losses via tile drainage in the late fall, winter and early spring, when most of the phosphorus loading occurs
The findings support efforts to reduce phosphorus levels in the Lake Erie Watershed by highlighting the importance of managing nutrient losses in both surface runoff and the amounts transported to tile drains. The U.S. Environmental Protection Agency has announced a goal of reducing phosphorus fertilizer runoff into the Great Lakes by more than 1,400 tons by 2019.
Read more about this work in the January 2015 issue of Agricultural Research magazine.
ARS is the USDA's principal intramural scientific research agency, and this research supports the USDA goal of promoting agricultural sustainability.