USDA
A Study of Switchgrass for Home Heating in the Northeast
ARS studies have found that it could be more economical to use switchgrass pellets instead of fuel oil to heat homes and businesses in the Northeast. Click the image for more information about
it.
- Immature switchgrass could help cellulosic ethanol industry
- A quick way to grade grasses for ethanol yields
- A new tool for improving switchgrass
March 21, 2013
Studies by a U.S. Department of Agriculture (USDA) scientist have provided a complete cost-benefit breakdown of using switchgrass pellets, which are potentially a cheaper source of energy, instead of fuel oil to heat homes and businesses in the Northeast.
Agricultural Research Service (ARS) researcher Paul Adler led efforts on a lifecycle analysis that compared costs of energy generation from coal, natural gas, fuel oil, and switchgrass in the form of energy-dense cubes, briquettes, and pellets. Adler works at the ARS Pasture Systems and Watershed Management Research Unit in University Park, Pa.
ARS is USDA's chief intramural scientific research agency, and this work supports the USDA priority of finding new sources of bioenergy.
The researchers calculated the economic outlays associated with switchgrass production throughout the supply chain, as well as greenhouse gas emissions generated by switchgrass production, densification, and conversion to heat and power. This included the first lifecycle inventory of switchgrass seed production and greenhouse gas emissions associated with seed production.
The analysis indicated that 192 pounds of "carbon dioxide equivalent," or CO2e, was emitted for every ton of switchgrass dry matter that was sown, harvested, and delivered to densification plants for processing into pellets. CO2e is a measurement used to compare the emissions from various greenhouse gases based upon their global warming potential.
The researchers calculated that using switchgrass pellets instead of petroleum fuel oil to generate one gigajoule of heat in residences would reduce greenhouse gas emissions by 146 pounds of CO2e. Totaling all costs associated with installing an appropriate residential heating system and fuel consumption, the team concluded that each gigajoule of heat produced using switchgrass pellets would cost $21.36. Using fuel oil to produce the same amount of heat would cost $28.22.
Adler is now working with Plainview Growers to determine how the carbon footprint differs between heating greenhouses with biomass and heating them with fuel oil. Plainview Growers, which has its headquarters in Pompton Plains, N.J., sells more than 160 million nursery plants produced from seeds every year.
Results from this research were published in Environmental Science & Technology.
Read more about this research in the March 2013 issue of Agricultural Research magazine.
Chemical Trickery Explored to Help Contain Potato Pest
Microscope image of a juvenile pale cyst nematode (right) emerging from an egg. Click the image for more information about
it.
- A better test for a potato pest
- New methods developed to detect, measure potato phytonutrients
- Pest-resistant potato on tap
March 18, 2013
The pale cyst nematode, Globodera pallida, is one bad roundworm.
Unchecked, the pest burrows into potato roots to feed, obstructing nutrients and causing stunted growth, wilted leaves and other symptoms that can eventually kill the plant. Severe infestations can cause tuber yield losses of up to 80 percent.
Now, however, U.S. Department of Agriculture (USDA) and cooperating scientists are evaluating new ways to control G. pallida using naturally occurring chemicals called egg-hatching factors.
According to lead scientist Roy Navarre, with USDA's Agricultural Research Service (ARS), the egg-hatching factors are actually chemicals exuded from the roots of potato and certain other solanaceous plants into surrounding soil. There, the chemicals stimulate G. pallida eggs to hatch.
Normally, this helps ensure the survival of emerging juvenile nematodes. But Navarre's approach calls for using the chemicals to "trick" the eggs into hatching when no potato plants are present, leaving juveniles without food or a host on which to reproduce.
His investigations are part a broader, multi-pronged control effort involving researchers from state universities, other ARS labs, and other federal and state agriculture departments.
G. pallida, a non-native species from Europe, was first detected in eastern Idaho in April 2006. To date, it's been found in and confined to 17 infested fields representing 1,916 total acres in Idaho's Bingham and Bonneville counties. Despite G. pallida's limited geographic distribution, its presence in U.S. soils has had far-reaching impact: closed or limited export markets, devalued farmland, regulatory restrictions and other economic hardships.
Fumigation is a key defense. However, the eggs are encased in cysts that can resist fumigation, according to Navarre, who works at the ARS Vegetable and Forage Crops Research Laboratory in Prosser, Wash.
He is exploring two approaches to force the eggs to hatch in the absence of a host: amending the soil with purified forms of egg-hatching factors, and planting sticky nightshade as a "trap crop" whose roots exude the chemicals, but don't support the nematode's reproduction.
Read more about this research in the March 2013 issue of Agricultural Research magazine.
ARS is USDA's principal intramural scientific research agency, and this research supports the USDA priority of promoting international food security.
A Better Understanding of the Impacts of Grazing Sheep
ARS research has found that grazing sheep on fallow fields in Montana and the Dakotas, a practice that has declined, generally has no negative effects on the soil and subsequent yields. Click the image for more information about
it.
- Natural selenium coproduct good for sheep
- Grazing of cattle pastures can improve soil quality
- Springtime sheep grazing helps control leafy spurge
March 14, 2013
A U.S. Department of Agriculture (USDA) scientist is giving guidance to growers in Montana and the Dakotas on how grazing sheep when fields are left fallow will affect soil quality.
Grazing sheep and other livestock was once common in the region before fertilizers were introduced in the 1950s. While fertilizers increased yields, they also have increased nitrogen runoff and leaching, made soils more acidic, and contributed to greenhouse gas emissions, according to Upendra Sainju, a soil scientist with the Agricultural Research Service (ARS) in Sidney, Mont. ARS is USDA's principal intramural scientific research agency.
Growers looking for alternatives have turned once again to grazing sheep during seasons when fields are left fallow. The trend in Montana and North Dakota prompted Sainju and his ARS colleagues to study the grazing's effects on crop quality, soil chemistry, and amounts of nutrients in the soil. Each can have long-term effects on crop yields.
Sainju and his colleagues set up three cropping systems (continuous spring wheat, spring wheat-fallow, and winter wheat-fallow) in southwestern Montana. They compared soil qualities on a series of plots where, during the fallow season, sheep were grazed, herbicides were used, or the soil was tilled for weed control.
Over four years, sheep were grazed at rates of up to 153 sheep per hectare (2.47 acres), glyphosate was applied at standard rates, and soils were tilled to a standard depth of 15 centimeters (5.9 inches). Soil samples from varying depths were analyzed for organic matter, nutrients, pH and electrical conductivity, which affects nutrient availability and plant growth.
The results showed that tillage did return more of the beneficial wheat residue to the soil than either grazing or the herbicide treatments, resulting in higher levels of calcium, sulfur, and electrical conductivity in the soil.
But grazing generally had no negative effects on soil organic matter and crop yields. The sheep returned to the soil some of the phosphorus and potassium they ate up in the wheat residue by way of their feces and urine. Grazing also increased levels of magnesium and sodium in the soil, possibly because the urine and feces contained higher levels of them.
The results of this study were published in the Agronomy Journal and Soil Science Society of America Journal.
Read more about this research in the March 2013 issue of Agricultural Research magazine.
Epigenetics Mechanism May Help Explain Effects of Mom's Nutrition on Her Children's Health
ARS-funded research has found that seasonal fluctuations in the foods Gambian women eat around the time of conception can affect the development of genes in their unborn children. Click the image for more information about
it.
- Ongoing research analyzes formulas, mother's milk
- Baby's obesity risk: What's Mom's influence?
- Kids and diabetes risk: Do chromosomes hold new clues?
March 11, 2013
Pioneering studies by U. S. Department of Agriculture-funded research molecular geneticist Robert A. Waterland are helping explain how the foods that soon-to-be-moms eat in the days and weeks around the time of conception—or what's known as periconceptional nutrition–may affect the way genes function in her children, and her children's health.
In an early study, Waterland and co-investigators examined gene function of 50 healthy children living in rural villages in the West African nation of The Gambia. The study has shaped some of Waterland's current research into the effects of nutrition on what geneticists refer to as epigenetic mechanisms. Those mechanisms can impact, for example, the levels at which an everyday biochemical process, DNA methylation, occurs at regions of certain genes. DNA methylation is essential for cell development and for stabilizing cell function.
In the West Africa study, Waterland and co-researchers found that levels of DNA methylation were higher at regions of five genes in children conceived during the peak rainy season months of August and September, when food would typically have been less available to their mothers.
According to Waterland, two of the five genes in which elevated DNA methylation occurred warrant further study because they are associated with risk of disease. Specifically, the SLITRK1 gene is associated with Tourette's syndrome, and the PAX8 gene is linked to hypothyroidism.
In a scientific article in PLoS Genetics, the researchers attributed the epigenetic variation to dramatic seasonal differences in the kinds and amounts of foods available in the three subsistence-farming villages that were the focus of the study.
An article in the March 2013 issue of Agricultural Research magazine tells more.
Waterland works at the Children's Nutrition Research Center in Houston, Texas, which is managed by the Agricultural Research Service, USDA's chief in-house scientific research agency, and by the Houston-based Texas Children's Hospital and Baylor College of Medicine, where Waterland is an associate professor of pediatrics and of molecular and human genetics. This research supports the USDA priority of improving children's health and nutrition.
Deterring Ticks with Citrus and Millipedes
Ticks like this lone star tick are repelled by natural compounds found in citrus and insects like millipedes. Click the image for more information about
it.
- Studying bed bug actions for new management tactics
- Barcording insects as a way to track and control them
- Researchers collect "signals intelligence" on insect pests
March 8, 2013
Why do birds, monkeys and other animals rub themselves with citrus and creatures like millipedes? One likely reason is because certain plants and arthropods contain natural repellents.
Scientists with the U.S. Department of Agriculture (USDA) and the Smithsonian Conservation Biology Institute (SCBI) at the National Zoological Park in Front Royal, Va., examined citrus compounds and millipedes for effectiveness against ticks. John Carroll, an entomologist with the Agricultural Research Service (ARS) at the Henry A. Wallace Beltsville Agricultural Research Center (BARC) in Beltsville, Md., and SCBI researcher Paul Weldon tested the responses of ticks to more than 20 different compounds in citrus extracts. ARS is the chief intramural scientific research agency of USDA.
Ticks were allowed to climb on vertical paper strips containing lemon rind exudates and other citrus chemicals. Repellency evaluation was based on whether ticks crawled into treated areas, continued to move, turned around, crawled back down or fell. Experiments also involved putting ticks inside treated filter-paper packets. After one hour, the ticks were removed, placed on their backs and timed to see if and when they could right themselves and climb out of a low enclosure and onto a fingertip.
Carroll, who works in BARC's Invasive Insect Biocontrol and Behavior Laboratory, found that some ticks were unable to crawl out of enclosures or even right themselves. Of 24 ticks exposed to one citrus chemical, only one righted itself. Of the chemicals tested, one killed or disabled ticks exposed to it for an hour. Several other chemicals kept ticks from climbing onto a fingertip.
To get to the bottom of why some animals anoint themselves with crushed millipedes, scientists used similar techniques to test ticks' responses to three benzoquinone chemicals found in millipedes. One benzoquinone chemical killed ticks, one repelled them and all three benzoquinones hampered efforts of ticks to right themselves and climb. Higher concentrations of these chemicals were able to impair ticks' ability to climb for several months.
Read more about this research in the March 2013 issue of Agricultural Research magazine.
Manure Spills: Detailing the Damage, Finding a Fix
Ticks like this lone star tick are repelled by natural compounds found in citrus and insects like millipedes. Click the image for more information about
it.
- Studying bed bug actions for new management tactics
- Barcording insects as a way to track and control them
- Researchers collect "signals intelligence" on insect pests
March 8, 2013
Why do birds, monkeys and other animals rub themselves with citrus and creatures like millipedes? One likely reason is because certain plants and arthropods contain natural repellents.
Scientists with the U.S. Department of Agriculture (USDA) and the Smithsonian Conservation Biology Institute (SCBI) at the National Zoological Park in Front Royal, Va., examined citrus compounds and millipedes for effectiveness against ticks. John Carroll, an entomologist with the Agricultural Research Service (ARS) at the Henry A. Wallace Beltsville Agricultural Research Center (BARC) in Beltsville, Md., and SCBI researcher Paul Weldon tested the responses of ticks to more than 20 different compounds in citrus extracts. ARS is the chief intramural scientific research agency of USDA.
Ticks were allowed to climb on vertical paper strips containing lemon rind exudates and other citrus chemicals. Repellency evaluation was based on whether ticks crawled into treated areas, continued to move, turned around, crawled back down or fell. Experiments also involved putting ticks inside treated filter-paper packets. After one hour, the ticks were removed, placed on their backs and timed to see if and when they could right themselves and climb out of a low enclosure and onto a fingertip.
Carroll, who works in BARC's Invasive Insect Biocontrol and Behavior Laboratory, found that some ticks were unable to crawl out of enclosures or even right themselves. Of 24 ticks exposed to one citrus chemical, only one righted itself. Of the chemicals tested, one killed or disabled ticks exposed to it for an hour. Several other chemicals kept ticks from climbing onto a fingertip.
To get to the bottom of why some animals anoint themselves with crushed millipedes, scientists used similar techniques to test ticks' responses to three benzoquinone chemicals found in millipedes. One benzoquinone chemical killed ticks, one repelled them and all three benzoquinones hampered efforts of ticks to right themselves and climb. Higher concentrations of these chemicals were able to impair ticks' ability to climb for several months.
Read more about this research in the March 2013 issue of Agricultural Research magazine.
Manure Spills: Detailing the Damage, Finding a Fix
ARS soil scientist Doug Smith is part of a team that studied how stream bed sediments capture and release phosphorus from manure runoff and identified strategies for reducing phosphorus loads from manure spills. Click the image for more information about
it.
- The lifetime journeys of manure-based microbes
- With feedlot manure, it pays to be precise
- E. coli can survive in streambed sediments for months
March 7, 2013
A manure spill that reaches a nearby creek or river can create a serious environmental hazard because it significantly boosts phosphorus loads in the water. Now scientists at the U.S. Department of Agriculture (USDA) and their research partners have determined how channel sediments capture and release manure phosphorus, and have identified strategies for reducing phosphorus loads from manure spills.
Agricultural Research Service (ARS) soil scientist Doug Smith and Shalamar Armstrong, who is now an assistant professor at Illinois State University, conducted several studies on the issue. Smith works at the ARS National Soil Erosion Research Laboratory in West Lafayette, Ind. ARS is USDA's chief intramural scientific research agency.
The scientists collected sediments from two drainage ditches in Indiana's Cedar Creek Watershed. They added the sediments to an artificial water channel and used swine manure minimally diluted with water to create their own worst-case manure "spill." After 24 hours, they cleaned up the "spill" using standard remediation protocols.
The researchers found the spill simulation initially resulted in an average dissolved phosphorus concentration of 5.57 milligrams per liter, as measured in a water column. The concentrations dropped to between 0.19 and 0.21 milligrams per liter 24 hours later, but still exceeded U.S. Environmental Protection Agency (EPA) standards for rivers, stream, and drainage ditches in the Cedar Creek Watershed.
The scientists found that channel sediments initially adsorbed phosphorus from the water at rates ranging from 8.9 to 16.7 milligrams per square meter of sediment per hour. However, after the simulated "cleanup," all the sediments released phosphorus back into the water at rates that increased phosphorus loads to levels that exceeded EPA's maximum acceptable levels by at least 67 percent.
In another study, the researchers observed that amending the contaminated sediments with 1.6 milligrams of alum/calcium carbonate per gram of sediment suppressed phosphorus release in sandy sediments by 92 percent, and suppressed phosphorus release in clay loam and loamy sand sediments by 72 percent. Higher amendment levels suppressed phosphorus release in all three soil types by up to 100 percent.
Findings from the studies were published in the Journal of Environmental Quality and the Journal of Environmental Monitoring.
Read more about this research in the March 2013 issue of Agricultural Research magazine.
Scientists Explore Brain, Cortisol, and Weight Loss Connections
New ARS studies of obesity could help put dieting on a more scientific basis. Photo courtesy of Microsoft clipart.
- Researchers analyze metabolites in blood
- Got fish? Nutrition studies explore health benefits
- Do soy isoflavones boost bone health?
March 4, 2013
Weight-management studies led by U.S. Department of Agriculture (USDA) scientists are helping determine why some dieters lose more weight than others, and are more successful in keeping it off.
Chemist Nancy L. Keim and nutrition scientist Kevin D. Laugero are conducting the investigations, which may lead to successful, science-based strategies for weight management. Both scientists are with the USDA's Agricultural Research Service (ARS) Western Human Nutrition Research Center in Davis, Calif. ARS is the USDA's chief intramural scientific research agency.
Given America's obesity epidemic, weight-management research is timely and relevant. The U.S. Centers for Disease Control and Prevention estimate that 35 percent of adults and 18 percent of kids and adolescents age 6 through 19 are overweight or obese. Both conditions are associated with increased risk of type 2 diabetes, cardiovascular disease and other chronic disorders.
In one investigation, 29 obese but otherwise healthy women age 20 to 45 participated in a 12-week weight-loss regimen. The researchers assessed several factors related to weight management, including the volunteers' patterns of decision making, and changes in their levels of cortisol, a stress-associated hormone.
The amount of weight that volunteers lost varied greatly, from zero to 27 pounds, despite the fact that all were essentially eating the same foods in the calorie-controlled meals provided to them at the nutrition center. Keim noted that the finding underscores the need for weight-management plans that are even more individualized than those available today.
The scientists also found that dieters who lost the most weight were those who scored the highest on the Iowa Gambling Task (IGT), a standard test that helps assess, for example, decision making and the ability to resist the temptation of short-term, immediate rewards in favor of longer-term benefits.
Though the idea of using the IGT in obesity research is not new, the ARS investigation is the first to show, in what scientists refer to as a controlled-feeding weight-loss trial, an association between IGT scores and diet-induced weight loss.
Cortisol findings were based on concentrations of the hormone in saliva samples collected throughout the day on two different test dates. The scientists found that volunteers' cortisol concentrations generally increased from the beginning to the end of the 12 weeks of dieting.
Laugero noted that increases in cortisol concentration have long been regarded as a reliable indicator of psychological stress, and that stress is considered to be a contributing factor to dieters' relapsing back to old eating habits and regaining weight.
Keim and Laugero collaborated in the study with physiologist and research leader Sean H. Adams and physiologist Marta D. Van Loan, both with the nutrition center, and with postdoctoral researcher Megan G. Witbracht of the University of California-Davis.
The research, published in Physiology and Behavior, was funded by ARS, the university, the National Dairy Council, the Dairy Council of California, and the National Institutes of Health.
Read more about this research in the March 2013 issue of Agricultural Research magazine.
An Interactive Atlas to Preserve Agricultural Biodiversity
ARS scientists have collaborated to publish an interactive atlas of 105 wild plant species in Guatemala that are closely related to crop plants, which will help protect genes that may be important to the future protection of food crops. Click the image for more information about
it.
- Overseas collections play important role in controlling invasive species
- ARS helps preserve indigenous crops in Ecuador
- International partnership to develop a global plant genebank information system
March 1, 2013
U.S. Department of Agriculture (USDA) scientists and cooperators have developed an interactive atlas of wild plants in Guatemala that are closely related to crop plants. The atlas will make it easier to preserve plants with genes that may be vital to global food security.
The Atlas of Guatemalan Crop Wild Relatives, accessible using a Google Earth interface, gives researchers and the public access to decades of data assembled by dozens of plant collectors in one of the richest regions of biodiversity in the world, according to Karen Williams, a botanist with the Agricultural Research Service (ARS) National Germplasm Resources Laboratory in Beltsville, Md. ARS is USDA's chief intramural scientific research agency, and this research supports the USDA priority of promoting international food security.
Of the 105 species of plants included, eight occur only in Guatemala, according to Williams, who worked on the atlas. Plant species were selected based on their importance to both world and Guatemalan agriculture.
The atlas is designed to provide Guatemalan scientists and land managers with information on where these crop wild relatives grow, which ones are most at risk, and which may be safe from habitat destruction. Scientists can use it to identify areas in need of protection.
Many of Guatemala's native plants are closely related to some of the most important crops in the United States, including corn, beans, peppers and potatoes. These crop wild relatives have genes that may be useful in addressing threats posed by emerging diseases, insect pests, and temperature and rainfall extremes arising from a changing climate.
Williams was part of an international team that spent 10 years working on the atlas. The researchers tracked down and compiled some 2,600 records of scientific specimens, which included when and where the plants were found, the appearance of the plants and descriptions of their native habitats. They consulted records from numerous germplasm collections and collections of dried plant specimens preserved in the United States, Guatemala, Honduras, and Mexico.
The atlas is currently available in Spanish only. Williams and her collaborators are translating it into English, and that translation is expected to be available within the year. The atlas and supporting data are available at http://www.ars.usda.gov/ba/atlascwrguatemala.
Read more about this research in the March 2013 issue of Agricultural Research magazine.
The Right Way to Roll Rye
A specialized "roller/crimper" that Alabama growers can use to terminate cover crops can reduce and sometimes eliminate the need for herbicides with the subsequent corn. Click the image for more information about
it.
- In organic cover crops, more seeds means fewer weeds
- Understanding why rye works as a cover crop
- Managing cover crops with rolling and crimping techniques
February 28, 2013
U.S. Department of Agriculture (USDA) scientists are giving guidance to farmers on using a tool designed to maximize the advantages of planting cover crops. The technology, known as a "roller/crimper," can reduce and sometimes eliminate the need for herbicides.
Cover crops can improve soil quality, and in organic operations, they play a major role in keeping weeds in check. Crimpers have been used for years in South America and are catching on in the United States, according to Ted Kornecki, an agricultural engineer with the Agricultural Research Service (ARS) National Soil Dynamics Laboratory in Auburn, Ala.
ARS is the USDA's principal intramural scientific research agency, and this research supports the USDA priority of promoting international food security.
Kornecki and his colleagues assessed the effects of three experimental rolling and crimping systems—including two they designed—on soil moisture, yield, and other factors in a northern Alabama sweet corn field. They planted cereal rye as a cover crop for three successive Octobers, crimped it each year during the following April with three different roller/crimpers, and planted sweet corn three weeks after that. They passed the crimpers over the rye at two different speeds to assess the effects of different speeds.
Using cereal rye as a cover crop helps the soil retain moisture, reduces erosion, promotes the formation of soil organic matter and provides a physical barrier to control weeds. The effectiveness of using rye with a crimper largely depends on the rye's "termination rate," or the percentage of it that dies off when it is crimped. Studies show termination rates of about 90 percent are optimal to ensure sufficient stalks and plant material remain on the soil to form a dry mat that can be penetrated with seeding equipment.
The results, published in 2012 in HortScience, showed that the roller types and operating speeds did not affect soil moisture, and that the rollers produced higher yields than the control treatment at both speeds. The rollers were not as effective at killing the rye as the chemical glyphosate applied as a control, but that was because the researchers planted the corn on the recommended dates, and that meant having to roll the rye earlier than when termination rates would have been optimal.
Based on their findings, the researchers recommend that growers in Alabama plant the rye by late September, instead of mid-October, so that it can be rolled two weeks earlier in the spring. They also recommend making multiple passes with the roller to increase termination rates.
Read more about this research in the February 2013 issue of Agricultural Research magazine.
Temperament Plays Key Role in Cattle Health
Even tempered cattle can be more productive and respond better to vaccines, according to research by ARS animal scientist Jeff Carroll (left) and animal physiologist Ron Randel from Texas AgriLife Research and Extension Center. Click the image for more information about
it.
- Cleaning cows from inside out
- Researchers uncover genetic link to cattle diseases
- Keeping cattle cool and stress-free is goal of ARS study
February 25, 2013
U.S. Department of Agriculture (USDA) and university scientists have found that cattle temperament influences how animals should be handled, how they perform and how they respond to disease.
The team of researchers looked at stressful events—such as weaning, transportation and vaccination—that beef cattle experience during routine management practices. The researchers examined interrelationships of stress and cattle temperament with transportation, immune challenges and production traits.
Studies were conducted by animal scientist and research leader Jeff Carroll at the Agricultural Research Service (ARS) Livestock Issues Research Unit (LIRU) in Lubbock, Texas; associate research professor Rhonda Vann at Mississippi State University's Brown Loam Branch Experiment Station; animal physiologist Ron Randel at Texas AgriLife Research, The Texas A&M University (TAMU) System, in Overton; and endocrinologist Tom Welsh, Texas A&M AgriLife Research and TAMU Department of Animal Science, in College Station.
Between 24 and 36 calves were used for each study, depending on the trial. An exit velocity system, which measures the rate at which an animal exits a squeeze chute and crosses a certain distance, was used to select for temperament. A pen scoring system was used in conjunction with exit velocity to calculate an overall temperament score for cattle selected as the calmest, the most temperamental or as intermediate.
When challenged with a bacterial toxin, cattle showed dramatic differences in sickness behavior, depending on their temperament. The more temperamental animals failed to show behaviors that allow detection of sick animals, whereas calm animals immediately displayed visual signs and became ill. Studies also revealed that temperamental cattle did not have the same vigorous immunological response to a vaccine as less temperamental cattle in the same herd.
In related research, the team found that the main cause of stress for cattle was not transportation itself, but being handled and loaded into a trailer.
However, transportation duration and conditions were found to have negative effects on intramuscular fat or marbling, which is used for fast sources of energy by cattle being transported. Marbling determines the quality grade of beef. Lower levels of marbling reduce quality grade. Temperamental cattle have less fat stores, indicating that temperament makes a difference in the final quality grade.
ARS is USDA's principal intramural scientific research agency.
Read more about this research in the February 2013 issue of Agricultural Research magazine.
The Lifetime Journeys of Manure-based Microbes
ARS scientists are studying the fate of cow manure in feedlots and in fields with an eye to increased food and environmental safety. Click the image for more information about
it.
- Organic compounds eliminate disease-causing pathogens
- E. coli can survive in streambed sediments for months
- Does grilling kill E. coli O157:H7?
February 22, 2013
Studies at the U.S. Department of Agriculture (USDA) are shedding some light on the microbes that dwell in cattle manure—what they are, where they thrive, where they struggle, and where they can end up.
This research, which is being conducted by Agricultural Research Service (ARS) scientists at the agency's Agroecosystems Management Research Unit in Lincoln, Neb., supports the USDA priority of ensuring food safety. ARS is USDA's chief intramural scientific research agency.
In one project, ARS microbiologist Lisa Durso used fecal samples from six beef cattle to identify a core set of bovine gastrointestinal bacterial groups common to both beef and dairy cattle. She also observed a number of bacteria in the beef cattle that had not been reported in dairy cows, and identified a diverse assortment of bacteria from the six individual animals, even though all six consumed the same diet and were the same breed, gender and age.
In another study, Durso collaborated with ARS agricultural engineer John Gilley and others to study how livestock diet affected the transport of pathogens in field runoff from manure-amended soils. The scientists added two types of manure to experimental conventional-till and no-till fields at 1-, 2-, or 4-year application rates. The manure had been collected from livestock that had consumed either corn or feed with wet distillers grains.
After a series of simulated rain events, the team collected and analyzed samples of field runoff and determined that neither diet nor tillage management significantly affected the transport of fecal indicator bacteria. But they did note that diet affected the transport of bacteriophages—viruses that invade bacteria—in field runoff.
Gilley also conducted an investigation into how standing wheat residues affected water quality in runoff from fields amended with 1-, 2-, or 4-year application rates of manure. The scientists found that runoff loads of dissolved phosphorus, total phosphorus, nitrates, nitrogen, and total nitrogen were much higher from plots with residue cover. The team also observed that runoff from fields amended with 4-year application rates of manure had significantly higher levels of total phosphorus and dissolved phosphorus than fields amended with 1-year or 2-year manure rates.
Results from these studies have been published in Foodborne Pathogens and Disease, Applied and Environmental Microbiology, and Transactions of the ASABE.
Read more about this research in the February 2013 issue of Agricultural Research magazine.
New Tool Gets to the Root of the Matter
A new tool developed by ARS and Cornell University researchers is giving scientists faster and more detailed looks at three-dimensional root architecture as it develops; here with Azucena rice. Click the image for more information about
it.
- What counts is the water that actually enters plant roots
- Infrared sheds light on beneficial microbes
- Glomalin is key to locking up soil carbon
February 19, 2013
A U.S. Department of Agriculture (USDA) scientist and his colleague at Cornell University have developed a new tool for studying how roots take shape in the soil.
The three-dimensional imaging system and software package, developed by Agricultural Research Service (ARS) scientist Leon V. Kochian in Ithaca, N.Y., and Randy T. Clark of Cornell, allows scientists to collect data on root systems faster than ever before, and to study root architecture in unprecedented detail. Root systems play a critical role in crop health, and like any structure, they have their own architecture.
Called "RootReader3D," the system gives scientists the ability to analyze root structures and growth patterns, to compare one root system with another, and to genetically map and explore traits that give plant roots the capacity to reach into the soil and collect water, phosphorous, and other nutrients.
Kochian is director of the ARS Robert W. Holley Center for Agriculture and Health at Ithaca, and Clark is a doctoral student in his laboratory. ARS is USDA's principal intramural scientific research agency, and this research supports the USDA priority of promoting international food security.
Previous systems allowed scientists to take three-dimensional images of root systems growing in gels, but those systems required up to an hour to collect enough data for a single three-dimensional image. With the RootReader3D system, scientists can produce images of more than 100 root systems a day, providing the information needed to conduct genetic mapping experiments.
To test their system, the researchers grew two very different varieties of rice, Azucena and IR64, in transparent gels and tracked root growth by imaging the plants and their roots for 10 days. The researchers found that they were able to delineate greater detail in the two root systems than ever before. Azucena had deeper roots than its irrigated cousin IR64, and the two root systems were significantly different in their "bushiness," how their root volume was distributed, and the vertical position of the center mass of the root system.
These results were published and featured on the June 2011 cover of Plant Physiology.
The researchers hope the data they collect using RootReader3D will help scientists identify genes controlling important root developmental traits. The goal is to help plant breeders develop varieties of rice and other crops with roots that make them better equipped to handle drought, heat, poor soil quality, and other stress factors in a changing world.
Read more about this research in the February 2013 issue of Agricultural Research magazine.
New Club Wheat is Tough on Fungi
A new tool developed by ARS and Cornell University researchers is giving scientists faster and more detailed looks at three-dimensional root architecture as it develops; here with Azucena rice. Click the image for more information about
it.
- What counts is the water that actually enters plant roots
- Infrared sheds light on beneficial microbes
- Glomalin is key to locking up soil carbon
February 19, 2013
A U.S. Department of Agriculture (USDA) scientist and his colleague at Cornell University have developed a new tool for studying how roots take shape in the soil.
The three-dimensional imaging system and software package, developed by Agricultural Research Service (ARS) scientist Leon V. Kochian in Ithaca, N.Y., and Randy T. Clark of Cornell, allows scientists to collect data on root systems faster than ever before, and to study root architecture in unprecedented detail. Root systems play a critical role in crop health, and like any structure, they have their own architecture.
Called "RootReader3D," the system gives scientists the ability to analyze root structures and growth patterns, to compare one root system with another, and to genetically map and explore traits that give plant roots the capacity to reach into the soil and collect water, phosphorous, and other nutrients.
Kochian is director of the ARS Robert W. Holley Center for Agriculture and Health at Ithaca, and Clark is a doctoral student in his laboratory. ARS is USDA's principal intramural scientific research agency, and this research supports the USDA priority of promoting international food security.
Previous systems allowed scientists to take three-dimensional images of root systems growing in gels, but those systems required up to an hour to collect enough data for a single three-dimensional image. With the RootReader3D system, scientists can produce images of more than 100 root systems a day, providing the information needed to conduct genetic mapping experiments.
To test their system, the researchers grew two very different varieties of rice, Azucena and IR64, in transparent gels and tracked root growth by imaging the plants and their roots for 10 days. The researchers found that they were able to delineate greater detail in the two root systems than ever before. Azucena had deeper roots than its irrigated cousin IR64, and the two root systems were significantly different in their "bushiness," how their root volume was distributed, and the vertical position of the center mass of the root system.
These results were published and featured on the June 2011 cover of Plant Physiology.
The researchers hope the data they collect using RootReader3D will help scientists identify genes controlling important root developmental traits. The goal is to help plant breeders develop varieties of rice and other crops with roots that make them better equipped to handle drought, heat, poor soil quality, and other stress factors in a changing world.
Read more about this research in the February 2013 issue of Agricultural Research magazine.
New Club Wheat is Tough on Fungi
Cara, a new white winter club wheat developed by ARS researchers, boasts high levels of disease resistance, especially to rusts, plus outstanding flour quality. Click the image for more information about
it.
- Uncovering the mystery of a major threat to wheat
- ARS, cooperators discover wheat gene with resistance to stripe rust
February 14, 2013
Pacific Northwest wheat growers now have added insurance against outbreaks of yield-robbing fungi, thanks to "Cara," a new, white winter club wheat cultivar developed by U.S. Department of Agriculture (USDA) scientists.
According to Kim Garland-Campbell, a geneticist with USDA's Agricultural Research Service (ARS) in Pullman, Wash., "Cara" is the product of a cooperative wheat breeding effort to combine high grain yields and flour quality with resistance to multiple fungal diseases. Of particular concern is stripe rust, a disease caused by the fungus Puccinia striiformis, which has inflicted yield losses of up to 40 percent in Washington and other Pacific Northwest states.
In fact, the release and subsequent sale of "Cara" in 2009 coincided with a stripe-rust epidemic that had overcome the resistance present in cultivars of club wheat that had been planted at the time, notes Garland-Campbell, who works at the ARS Wheat Genetics, Quality, Physiology and Disease Research Unit in Pullman. ARS is USDA's principal intramural scientific research agency.
Based on 60 yield trials conducted in plots where stripe rust was present in Oregon and Washington, "Cara" outperformed most other commercial cultivars, with two-year averages ranging from three to 18 percent better than the other wheats used in the evaluations.
"Cara," which was derived from crossing three diverse wheat germplasm sources, is primarily adapted to the Palouse and other rust-prone areas of the Pacific Northwest that receive 15 to 24 inches of precipitation annually. In addition to stripe rust, "Cara" carries genes for fungal disease resistance to straw breaker foot rot and powdery mildew.
"Cara" also scored high on standard industry evaluations for milling, baking and other end-use properties. For example, like other club wheats, flour milled from "Cara" has low viscosity and protein content, coupled with high "break flour" and "weak gluten," characteristics ideal for making air-leavened cakes, sugar snap cookies, biscuits, pastries and other soft, fluffy-textured baked goods.
Read more about this research in the February 2013 issue of Agricultural Research magazine.
Studying Bed Bug Actions for New Management Tactics
ARS scientists are identifying new compounds to control bed bugs. Click the image for more information about
it.
- Barcording insects as a way to track and control them
- Researchers collect "signals intelligence" on insect pests
- ARS study provides a better understanding of how mosquitoes find a host
February 11, 2013
Learning more about the behavior of bed bugs is one approach being used by U.S. Department of Agriculture (USDA) scientists to identify compounds to help control these pests.
The resurgence of bed bugs over the last decade has caused problems in major U.S. cities where they infest homes, apartments, hotels, shelters and even places of work. The small, blood-feeding insects are not known to transmit diseases, but they can cause severe reactions in people who are allergic to them. Bed bugs usually go unnoticed until their numbers increase significantly, and getting rid of them can be costly.
Entomologist Mark Feldlaufer and chemist Kamlesh Chauhan at the Agricultural Research Service (ARS) Henry A. Wallace Beltsville Agricultural Research Center (BARC) in Beltsville, Md., have identified two new alarm pheromones—4-oxo-hexenal and 4-oxo-octenal—in immature bed bugs. The releasing of alarm pheromones, which are defensive compounds, causes aggregated bed bugs to scatter.
Scientists collected cast skins that retain chemicals from the bed bug's scent glands and then used gas chromatography and mass spectrometry technology to analyze and identify compounds. Swedish researchers subsequently identified the same compounds from a related species, the tropical bed bug, demonstrating that the compounds are biologically active.
This indicates that alarm pheromones may have implications in bed bug management, according to Feldlaufer, who works at BARC's Invasive Insect Biocontrol and Behavior Laboratory. By causing insects to disperse, the likelihood of bed bugs coming into contact with a control agent increases.
ARS and University of Nevada-Reno scientists also identified 17 compounds in the bed bug's outer protective layer of skin, a discovery they believe may play an important role in bed bug aggregation behavior.
Read more about this research in the February 2013 issue of Agricultural Research magazine.
ARS is USDA's principal intramural scientific research agency.
Virus Helps Scientists Identify "Who's Who" Among Two Veggie Enemies
ARS plant pathologist Carolee Bull is sorting out "who's who" between two easily confused bacteria that attack and ruin some of the same crops, such as broccoli, cabbage, and cauliflower. Click the image for more information about
it.
- Researchers use oxygenated phosphine fumigation to control insect pests
- Combating cucurbit yellow stunting disorder virus
- ARS releases iceberg lettuce breeding lines resistant to bacterial leaf spot
February 8, 2013
Natural warfare between a virus and a Pseudomonas bacterium is helping U.S. Department of Agriculture (USDA) scientists continue to learn about the bacterium's ability to kill arugula, broccoli, and several other cruciferous vegetables.
USDA plant pathologist Carolee T. Bull and her colleagues use the virus, known as PBSPCA1, as the basis for a lab test that helps quickly identify Pseudomonas cannabina pv. (pathovar) alisalensis. Bull works in the Agricultural Research Service (ARS) Crop Improvement and Protection Research Unit in Salinas, Calif. ARS is USDA's chief intramural scientific research agency.
In ongoing research that dates back to 1998, Bull and her co-investigators have detected and identified this pseudomonad; clarified its taxonomy, or "family tree"; and determined that it is the culprit behind a costly disease called bacterial blight of crucifers. The blight causes water-soaked spots to appear on plant leaves. Eventually, the spots coalesce and turn brown, giving the leaves an unattractive, burnt appearance that makes the vegetable unmarketable.
Early on, the scientists' field, greenhouse, and laboratory studies indicated that the crucifer blight bacterium could be easily confused with a close cousin, P. syringae pv. maculicola, which causes pepper spot disease. The two different pseudomonads kill some of the same vegetable crops, and several standard lab tests can't reliably tell which bacterium is which.
Bull and her colleagues chose the PBSPCA1 virus as the basis for a lab assay that reliably sorts out "who's who" among the two confusing bacteria. Because it can kill the crucifer blight bacterium, but not the pepper spot pseudomonad, the virus can be used to differentiate one from the other.
Bull and her coworkers begin using PBSPCA1 for preliminary diagnoses in 2002, and have continued to improve the assay.
The virus and both of the bacteria are harmless to humans.
The bacterium that the team was to later identify as the cause of crucifer blight began showing up in vegetable fields in California's Salinas Valley in 1995. Bull began investigating the mysterious microbe three years later. Within a few years, her team had resolved much of the confusion surrounding it.
Today, Bull and her co-investigators continue to help growers and plant pathologists in the United States and abroad identify the crucifer blight bacterium. Positive identification matters, especially when growers are deciding what to plant. For example, the Salinas studies have shown that broccoli, cabbage, and cauliflower are vulnerable to both the crucifer blight and the pepper spot bacteria, while some other crops, such as lettuce, are not.
Read more about this research in the February 2013 issue of Agricultural Research magazine.
Understanding Microbes Blowing in the Wind
ARS plant pathologist Carolee Bull is sorting out "who's who" between two easily confused bacteria that attack and ruin some of the same crops, such as broccoli, cabbage, and cauliflower. Click the image for more information about
it.
- Researchers use oxygenated phosphine fumigation to control insect pests
- Combating cucurbit yellow stunting disorder virus
- ARS releases iceberg lettuce breeding lines resistant to bacterial leaf spot
February 8, 2013
Natural warfare between a virus and a Pseudomonas bacterium is helping U.S. Department of Agriculture (USDA) scientists continue to learn about the bacterium's ability to kill arugula, broccoli, and several other cruciferous vegetables.
USDA plant pathologist Carolee T. Bull and her colleagues use the virus, known as PBSPCA1, as the basis for a lab test that helps quickly identify Pseudomonas cannabina pv. (pathovar) alisalensis. Bull works in the Agricultural Research Service (ARS) Crop Improvement and Protection Research Unit in Salinas, Calif. ARS is USDA's chief intramural scientific research agency.
In ongoing research that dates back to 1998, Bull and her co-investigators have detected and identified this pseudomonad; clarified its taxonomy, or "family tree"; and determined that it is the culprit behind a costly disease called bacterial blight of crucifers. The blight causes water-soaked spots to appear on plant leaves. Eventually, the spots coalesce and turn brown, giving the leaves an unattractive, burnt appearance that makes the vegetable unmarketable.
Early on, the scientists' field, greenhouse, and laboratory studies indicated that the crucifer blight bacterium could be easily confused with a close cousin, P. syringae pv. maculicola, which causes pepper spot disease. The two different pseudomonads kill some of the same vegetable crops, and several standard lab tests can't reliably tell which bacterium is which.
Bull and her colleagues chose the PBSPCA1 virus as the basis for a lab assay that reliably sorts out "who's who" among the two confusing bacteria. Because it can kill the crucifer blight bacterium, but not the pepper spot pseudomonad, the virus can be used to differentiate one from the other.
Bull and her coworkers begin using PBSPCA1 for preliminary diagnoses in 2002, and have continued to improve the assay.
The virus and both of the bacteria are harmless to humans.
The bacterium that the team was to later identify as the cause of crucifer blight began showing up in vegetable fields in California's Salinas Valley in 1995. Bull began investigating the mysterious microbe three years later. Within a few years, her team had resolved much of the confusion surrounding it.
Today, Bull and her co-investigators continue to help growers and plant pathologists in the United States and abroad identify the crucifer blight bacterium. Positive identification matters, especially when growers are deciding what to plant. For example, the Salinas studies have shown that broccoli, cabbage, and cauliflower are vulnerable to both the crucifer blight and the pepper spot bacteria, while some other crops, such as lettuce, are not.
Read more about this research in the February 2013 issue of Agricultural Research magazine.
Understanding Microbes Blowing in the Wind
ARS research is shedding new light on hitchhiking by microbes in soils carried off by strong winds, which could lead to better ways to minimize soil damage from wind erosion. Click the image for more information about
it.
- Modeling erosion of particulate matter
- No-till farming improves soil stability
- ARS studies effect of wind sandblasting on cotton plants
February 6, 2013
With help from a wind tunnel and the latest DNA technology, U.S. Department of Agriculture (USDA) scientists are shedding light on the travel patterns of microbes in soils carried off by strong winds. The work has implications for soil health and could lead to management practices that minimize the damage to soils caused by wind erosion.
Wind erosion is an emerging issue in soil conservation efforts. Agricultural Research Service (ARS) scientists have been studying wind-eroded soils since the 1930s, but few studies have focused on the effects of wind on the bacteria, fungi, and protozoa in the soil. ARS is USDA's chief intramural scientific research agency.
Researchers see an increasing need to focus on pathogens and agriculturally important bacteria carried in dust. ARS soil scientist Veronica Acosta-Martinez, with the agency's Wind Erosion and Water Conservation Unit in Lubbock, Texas, focused on bacterial populations that could be classified by DNA sequencing. She worked with Terrence Gardner, a visiting scientist from Alabama A&M University.
Researchers collected airborne dust and samples of a type of organic soil susceptible to wind erosion from fields where potatoes, beets and onions had grown a few years earlier and exposed them to windy conditions using a portable wind tunnel. They characterized the bacteria they found in both the "source soils" and the wind-eroded sediments, focusing on types of bacteria associated with coarse particles and on the types associated with fine dust particles.
They classified the bacteria found in each type of soil and wind-eroded sediment using pyrosequencing, a process that allowed them to identify up to 100 times more DNA in each sample than they would have detected with traditional methods. The study results, published online in the Journal of Environmental Quality, showed that certain types of bacteria, known as Bacteroidetes, were more predominant in the fine dust. Other types, known as Proteobacteria, were more predominant in coarse sediments.
Studies have shown that Bacteroidetes resist desiccation and thus can survive in extreme conditions when carried long distances. The fact that Proteobacteria were associated with coarse eroded sediments, which travel shorter distances, may explain how soils can retain important qualities despite damaging winds. Proteobacteria play an important role in carbon and nitrogen cycling, and their fate in dust storms will be the focus of future research, according to Acosta-Martinez.
Read more about this research in the February 2013 issue of Agricultural Research magazine.
Mix-and-Match Cover Cropping Can Optimize Organic Production
ARS research is providing organic lettuce and broccoli growers with information about how to use cover crops to fine-tune their crop production. Click the image for more information about
it.
- Tall fescue helps protect peach trees from nematodes
- Using ground covers in organic production
- In organic cover crops, more seeds means fewer weeds
February 4, 2013
Farmers can fine-tune their use of cover crops to help manage costs and maximize benefits in commercial organic production systems, according to U.S. Department of Agriculture (USDA) scientists.
Production expenses for high-value organic crops like lettuce and broccoli can exceed $7,000 per acre, so producers often try to streamline costs with an annual two- to three-crop rotation. Agricultural Research Service (ARS) horticulturalist Eric Brennan designed a long-term investigation that examined several different cover cropping strategies for an annual organic lettuce-broccoli production system. ARS is USDA's chief intramural scientific research agency, and this work supports the USDA priority of promoting international food security.
The researcher selected three winter cover crops often grown in the Salinas, Calif., area—rye, mustard, and a legume-rye mix—and planted each cover crop using either a typical seeding rate or a seeding rate that was three times higher. Seeding rates can influence a cover crop's ability to smother weeds.
During lettuce and broccoli production, Brennan ensured all systems received the same fertilizer and irrigation inputs and pest management. The harvest and sale of the crops, which met all USDA organic standards, were conducted by a commercial harvester.
Brennan's results indicated that all three cover crops yielded more dry matter than the two tons of crop residue per acre often recommended for maintaining soil organic matter. The legume-rye and rye cover crops produced approximately 25 percent more dry matter biomass than the mustard crops. But effectively suppressing weeds with the legume-rye crops required seeding at three times the typical rate, while rye and mustard crops appeared to suppress weeds adequately with typical seeding rates.
The long-term study also provided Brennan with more data about year-to-year yield variations in the legume-rye mix, including why legumes, which make up most of the seed costs, are not consistently abundant. Brennan thinks cooler early-season weather helps legumes compete with the rye. So when a hot and dry autumn is expected, producers might want to use a rye cover crop and skip spending the money on a cover crop with legumes.
Brennan, who works at the ARS Crop Improvement and Protection Research Unit in Salinas, has published some his findings in Agronomy Journal and Applied Soil Ecology.
Read more about this research in the February 2013 issue of Agricultural Research magazine.
