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ARS scientists Martha Anderson and Bill Kustas have developed a drought modeling system to help forecasters monitor drought conditions across the United States and the world. Click the image for more information about it.

Using remote sensing to map soil salinity on a regional scale   Aerial imagery system helps save water   Taking earth's temperature via satellite

A New Tool for Mapping Water Use and Drought

By Dennis O'Brien
February 7, 2012

Farmers and water managers may soon have an online tool to help them assess drought and irrigation impacts on water use and crop development, thanks to the work of two U.S. Department of Agriculture (USDA) scientists.

Agricultural Research Service (ARS) scientists Martha Anderson and Bill Kustas have developed an evapotranspiration (ET) and drought modeling system at the ARS Hydrology and Remote Sensing Laboratory in Beltsville, Md. The modeling system also will help forecasters monitor ET and drought conditions across the United States and overseas.

ARS is USDA's principal intramural scientific research agency, and the research supports the USDA priorities of responding to climate change and promoting international food security.

The model, known as ALEXI (Atmosphere-Land Exchange Inverse), uses thermal infrared imagery from satellites and calculates soil and plant temperatures that can be used to create maps of ET rates of plants growing in cultivated areas, forests and natural habitats around the world.

ET consists of the water evaporated from soil and plant surfaces, and the water vapor that escapes, or transpires, through plant leaf pores (stomata) as the plants absorb carbon dioxide through photosynthesis. Generally, evaporation cools surfaces, so a cooler land surface is an indicator of higher ET rates and wetter soils.

Water stress elevates soil and leaf temperatures, which can be detected by satellites. Anderson and Kustas can use satellite temperature data to create ET maps. The maps are capable of detecting rivers, lakes, wetlands, riparian buffers, irrigated cropland and areas under water stress.

The work is funded by the National Oceanic and Atmospheric Administration (NOAA) and the National Aeronautics and Space Administration (NASA). NOAA plans to use the system to generate ET estimates over the continental United States. The system is expected to become particularly relevant as climate change presents challenges for growers and water managers in areas such as the Texas Panhandle, the Florida Everglades and the southwestern United States.

Getting routine ET estimates for individual fields is laborious, but the researchers are streamlining the process. With help from new satellite imagery, they hope to be able to move toward routine mapping at the "field scale" level.

ALEXI has been estimating evapotranspiration (ET) rates since 2000, but the researchers continue to refine the system and plan to make the maps available online soon on the U.S. Drought Portal at www.drought.gov.

Anderson and Kustas, with colleagues, are currently mapping parts of Africa, including the Horn of Africa, where drought has caused famine in Somalia. Local ET data would be particularly helpful in places such as Africa, where networks of weather stations don't exist.

Read more about this research in the February 2012 issue of Agricultural Research magazine.

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Cheatgrass-choked steppe rangeland. Click the image for more information about it.

A program called Ecologically-Based Invasive Plant Management developed by ARS researchers can help restore rangelands choked with invasive weeds like cheatgrass (top) to a healthy ecosystem with a mix of shrubs, perennials, grasses and forbs.

Rangeland supporting a mix of desirable shrubs, perennials, grasses and forbs. Click the image for more information about it.

Seeding strategies help rangelands recover from fire   Burning invasive juniper trees boosts perennial grass recovery   Livestock can help rangelands recover from fires

New Insights into Invasive Plant Management

By Ann Perry
February 3, 2012

Over a decade of research at the U.S. Department of Agriculture (USDA) has resulted in the development of a new matrix for invasive plant management. The model was created by scientists with the Agricultural Research Service (ARS) in Burns, Ore., and helps land managers recognize how rangeland degradation processes vary across landscapes. ARS is USDA's chief scientific research agency.

Using the model can also increase the success rate of restoring native vegetation on damaged landscapes, which supports the USDA priority of responding to climate change.

Ecologist Roger Sheley synthesized a range of findings from scientific literature and field research to develop the model, which is called Ecologically Based Invasive-Plant Management (EBIPM). The process is a mix of plant establishment and succession theories, ecological principles, the identification of parameters that contribute to invasive plant management, and management actions that help restore native forage plants for livestock and wildlife. Sheley works at the ARS Range and Meadow Forage Management Research Unit in Burns.

Sheley and his colleagues based EBIPM on three general causes of plant succession: site availability, species availability, and species performance. They identified site-specific ecological processes that influence plant succession dynamics and determined how these processes are modified by environmental and human factors that affect plant establishment and long-term vegetation change. This information can be used to fine-tune the mechanisms and processes influencing plant succession, all of which helps rout invasive plants and support the return of native grasses and forbs.

Sheley and his colleagues tested their model in Montana's Kicking Horse Wildlife Mitigation Area at three sites that had varying degrees and types of damage from invasive plants. Using EBIPM, Sheley was able to increase the chance of restoration success by 66 percent over traditional approaches to invasive weed management. Sheley believes that EBIPM, which is also called "augmentative restoration," could be a valuable new tool for land managers in the western rangelands, where invasive plants like cheatgrass are fueling wildfires and limiting livestock grazing options.

Results from this work have been published in Rangeland Ecology and Management, Journal of Invasive Plant Science and Management, and www.ebipm.org.

Read more about Sheley's research in the February 2012 issue of Agricultural Research magazine.

Read the magazine story to find out more.

A specific gene in corn seems to confer resistance to three important leaf diseases—southern corn leaf blight, northern leaf blight, and gray leaf spot—all of which cause lesions on corn leaves worldwide. Click the image for more information about it.

Scientists test corn genes with MAGIC   Tapping into corn's tropical diversity   Corn research unlocks basis of natural diversity and reveals genetics of flowering and hybrid vigor

Corn Gene Helps Fight Multiple Leaf Diseases

By Sharon Durham
February 1, 2012

A specific gene in corn seems to confer resistance to three important leaf diseases, according to U.S. Department of Agriculture (USDA) scientists and their university colleagues.

This discovery, published in 2011 in the Proceedings of the National Academy of Sciences, could potentially help plant breeders build disease-resistance traits into future corn plants.

The research team included Agricultural Research Service (ARS) plant geneticists Peter Balint-Kurti, Jim Holland and Matt Krakowsky in the agency's Plant Science Research Unit in Raleigh, N.C., and scientists with the University of Delaware, Cornell University, and Kansas State University. ARS is the USDA's chief intramural scientific research agency.

Three diseases-southern corn leaf blight, northern leaf blight, and gray leaf spot-all cause lesions on corn leaves worldwide. In the U.S. Midwest Corn Belt, northern leaf blight and gray leaf spot are significant problems.

The researchers examined 300 corn varieties from around the world to ensure a genetically diverse representation. No corn variety has complete resistance to any of these diseases, but varieties differ in the severity of symptoms they exhibit.

The researchers set out to look for maize lines with resistance to the three diseases to determine which genes underlie disease resistance, according to Balint-Kurti. When they tested the lines for resistance, they found that if a corn variety was resistant to one disease, chances were favorable that it was also resistant to the other two.

The researchers applied a statistical analysis technique called "association mapping" to identify regions of the genome associated with variation in disease resistance. According to Balint-Kurti, the scientists knew there was a strong correlation between resistance of one disease and the other two. They postulated that some resistance genes conferred resistance to two or more different diseases, and they identified a gene that seemed to confer multiple disease resistance.

This gene, a GST (glutathione S-transferase), is part of a family of genes known for their roles in regulating oxidative stress and in detoxification. Both of these functions are consistent with a role in disease resistance.

Read more about this research in the February 2012 issue of Agricultural Research magazine.

Read the magazine story to find out more.

A commercial vaccine has been found to provide protection against leptospirosis, a disease that can infect all farm animals, rodents, and wildlife including California sea lions, which periodically undergo acute outbreaks. Photo courtesy of The Marine Mammal Center.

Researchers uncover genetic link to cattle diseases   Test vaccines show promise against parasite of cattle   Lifestyle options dwindle for bovine bacteria

Vaccine Protects Against Leptospirosis

By Sandra Avant
January 30, 2012

Scientists at the U.S. Department of Agriculture (USDA) have found that a commercial vaccine is effective against leptospirosis in cattle.

A widespread zoonotic disease, leptospirosis is transmitted naturally from domestic and wild animals to humans. The contagious disease, which is caused by Leptospira bacteria, is spread through contact with food, water or soil contaminated with urine from infected animals. It can affect all farm animals, rodents and wildlife.

Several years ago, retired microbiologist Richard Zuerner, veterinary medical officer David Alt and their colleagues at the Agricultural Research Service (ARS) National Animal Disease Center (NADC) in Ames, Iowa, tested a version of this vaccine and discovered that it induced some protection against experimental infection with Leptospira borgpetersenii serovar Hardjo, the main cause of bovine leptospirosis.

ARS is USDA's chief intramural scientific research agency, and this research supports USDA priority of promoting international food security.

Alt and his colleagues, who work at the NADC Infectious Bacterial Diseases Research Unit, examined the vaccine's potency in reducing the shedding of bacteria, potentially affecting the spreading of leptospirosis in herds. They vaccinated cattle twice with this vaccine or twice with a standard or control vaccine.

To test the vaccine's ability to induce short- and long-term immunity to infection, cattle were challenged with L. borgpetersenii serovar Hardjo three months or one year after immunization.

Scientists found that the vaccine appeared to be effective at both three-month and one-year periods after vaccination. Although the vaccine did not provide complete protection from shedding at one year after vaccination, it induced greater immunologic responses and protection against shedding of leptospirosis than the standard vaccine.

After cattle were challenged three months after vaccination, bacteria were detected in the urine for several weeks, but the cattle appeared to be capable of clearing the infection, whereas non-vaccinated cattle remained infected, according to Zuerner.

Only one vaccinated animal in the year-long study was shown to have bacteria in the kidney at the end of the live challenge, but most animals had evidence of short-term kidney infections that eventually cleared, according to Zuerner.

Although the vaccine was partially successful in protecting cattle against leptospirosis, scientists agree that improvement is still needed.

Choosing the right vaccine depends on identifying the infecting serovar, according to Alt. The diverse organisms of Leptospira bacteria contain more than 200 serovars that can cause the disease.

Findings from this research were published in Clinical and Vaccine Immunology.

Read more about this research in the January 2012 issue of Agricultural Research magazine.

ARS Food and Nutrition Research Briefs Issued

By Kim Kaplan
January 27, 2012

Drinking soy milk rather than cow's milk or mother's milk can result in better bones, at least in piglets, according to findings reported in the latest issue of the Agricultural Research Service (ARS) Food and Nutrition Research Briefs and its Spanish-language edition (Informe de investigaciones de alimentos y nutrición).

View the English edition at http://www.ars.usda.gov/is/np/fnrb/fnrb0112.htm

The popular online newsletter reports discoveries from researchers at ARS laboratories nationwide.

Among other findings, the current issue reports that:

• Research has not shown any significant increase or decline in mineral content of new broccoli varieties.

• Researchers are identifying ways to help identify breeding wheats that could make the best whole-grain cookie doughs.

• A cacao collecting trip may help save chocolate from witches' broom disease.

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 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 U.S. Department of Agriculture's chief scientific research agency.

New Issue of Healthy Animals Now Online

By Sandra Avant
January 26, 2012

The Agricultural Research Service (ARS) today posted a new issue of Healthy Animals. This quarterly online newsletter compiles ARS news and expert resources on the health and well-being of agricultural livestock, poultry and fish.

Each quarter, one article in Healthy Animals focuses on a particular element of ARS animal research. The current issue examines some of the collaborative partnerships formed by ARS and international agencies to control destructive diseases that threaten the health of livestock in developing nations and other parts of the world.

Other research highlighted in this issue includes:

• Scientists' discovery of genetic resistance to nematode parasites that infect sheep.
• A widely popular variety of forage grass for livestock.
• The potential of "biochar"—charred biomass created from wood, other plant material and manure—to improve soils.

Professionals interested in animal health issues might want to bookmark the site as a resource for locating animal health experts. An index lists ARS research locations covering 70 animal health topics. These range from specific diseases, such as Lyme disease, to broad subjects such as nutrition or parasites.

The site also provides complete contact information for the 25 ARS research groups that conduct studies aimed at protecting and improving farm animal health.

To receive an e-mail alert about each issue's online posting, contact Sandra Avant, ARS Information Staff, or sign up online.

ARS is the principal intramural scientific research agency of the U.S. Department of Agriculture.

The new USDA Plant Hardiness Zone Map is more sophisticated and accurate than any other previously developed. Click the image for link to zone map web site.

USDA Unveils New Plant Hardiness Zone Map

By Kim Kaplan
January 25, 2012

WASHINGTON—The U.S. Department of Agriculture (USDA) today released the new version of its Plant Hardiness Zone Map (PHZM), updating a useful tool for gardeners and researchers for the first time since 1990 with greater accuracy and detail. The new map—jointly developed by USDA's Agricultural Research Service (ARS) and Oregon State University's (OSU) PRISM Climate Group—is available online at www.planthardiness.ars.usda.gov. ARS is the chief intramural scientific research agency of USDA.

For the first time, the new map offers a Geographic Information System (GIS)-based interactive format and is specifically designed to be Internet-friendly. The map website also incorporates a "find your zone by ZIP code" function. Static images of national, regional and state maps also have been included to ensure the map is readily accessible to those who lack broadband Internet access.

"This is the most sophisticated Plant Hardiness Zone Map yet for the United States," said Catherine Woteki, USDA Under Secretary for Research, Education and Economics. "The increases in accuracy and detail that this map represents will be extremely useful for gardeners and researchers."

Plant hardiness zone designations represent the average annual extreme minimum temperatures at a given location during a particular time period. They do not reflect the coldest it has ever been or ever will be at a specific location, but simply the average lowest winter temperature for the location over a specified time. Low temperature during the winter is a crucial factor in the survival of plants at specific locations.

The new version of the map includes 13 zones, with the addition for the first time of zones 12 (50-60 degrees Fahrenheit) and 13 (60-70 degrees Fahrenheit). Each zone is a 10-degree Fahrenheit band, further divided into 5-degree Fahrenheit zones "A" and "B."

To help develop the new map, USDA and OSU requested that horticultural and climatic experts review the zones in their geographic area, and trial versions of the new map were revised based on their expert input.

Compared to the 1990 version, zone boundaries in this edition of the map have shifted in many areas. The new map is generally one 5-degree Fahrenheit half-zone warmer than the previous map throughout much of the United States. This is mostly a result of using temperature data from a longer and more recent time period; the new map uses data measured at weather stations during the 30-year period 1976-2005. In contrast, the 1990 map was based on temperature data from only a 13-year period of 1974-1986.

However, some of the changes in the zones are a result of new, more sophisticated methods for mapping zones between weather stations. These include algorithms that considered for the first time such factors as changes in elevation, nearness to large bodies of water, and position on the terrain, such as valley bottoms and ridge tops. Also, the new map used temperature data from many more stations than did the 1990 map. These advances greatly improved the accuracy and detail of the map, especially in mountainous regions of the western United States. In some cases, they resulted in changes to cooler, rather than warmer, zones.

While about 80 million American gardeners, as well as those who grow and breed plants, are the largest users of the USDA Plant Hardiness Zone Map, many others need this hardiness zone information. For example, the USDA Risk Management Agency uses the USDA plant hardiness zone designations to set some crop insurance standards. Scientists use the plant hardiness zones as a data layer in many research models such as modeling the spread of exotic weeds and insects.

Although a poster-sized version of this map will not be available for purchase from the government as in the past, anyone may download the map free of charge from the Internet onto their personal computer and print copies of the map as needed.

As USDA's chief scientific research agency, ARS is leading America towards a better future through agricultural research and information. ARS conducts research to develop and transfer solutions to help answer agricultural questions that impact Americans every day. ARS research helps to:

• ensure high-quality, safe food and other agricultural products;
• assess the nutritional needs of Americans;
• sustain a competitive agricultural economy;
• enhance the natural resource base and the environment; and
• provide economic opportunities for rural citizens, communties and society as a whole.

Read the magazine story to find out more.

Ranchers in the Intermountain West can reduce feeding costs by grazing their animals on the forage kochia, an Asian plant that sometimes survives wildfires and other environmental challenges better than native plants. Click the image for more information about it.

ARS and New Mexico scientists take a long look at livestock and locoweed   A better breed of plants helps revive western rangelands   ARS research helps develop new leads in cleft palate repair

Finding New Forages for Rangeland Cattle

By Ann Perry
January 24, 2012

Cattle that graze on rangelands in the western United States may soon have a new forage option, thanks to work by a U.S. Department of Agriculture (USDA) scientist.

Research by geneticist Blair Waldron with USDA's Agricultural Research Service (ARS) in Logan, Utah, suggests that forage kochia (Kochia prostrata) can provide more nutritious winter forage than traditional rangeland vegetation.

ARS is USDA's chief intramural scientific research agency, and this work supports the USDA priorities of responding to climate change and promoting international food security.

Waldron and his cooperators in Utah partnered to learn more about forage kochia, a shrubby Asian native plant that sometimes survives wildfires and other environmental challenges more successfully than North American native plants. Waldron works at the ARS Forage and Range Research Laboratory in Logan.

In a series of studies, the team found that forage kochia can be established on damaged rangelands, and that it can compete with cheatgrass successfully. It can even protect against wildfires.

Waldron and his research partners also investigated fall/winter rangeland forage yields, rangeland carrying capacities, nutritive values, and the livestock performance of cattle that spent the fall and winter grazing on either kochia-dominated rangelands or grass-dominated rangelands. The team stocked each site with predominately Black Angus cattle and ran field trials for two seasons.

They found that the forage yield on rangelands seeded with kochia was 2,309 pounds per acre, which was six times greater than the forage yield on traditional grazinglands. This difference meant that the rangelands with kochia could support 1.38 animals per acre, while the traditional rangelands could support only 0.24 animal per acre.

In addition, the experimental forage had a crude protein content of 11.7 percent, well above the recommended minimum, while the stockpiled grasses had a crude protein content of only 3.1 percent, which was below the recommended minimum.

Results from this research were published in Forage and Grazinglands, Journal of Extension, Small Ruminant Research, and elsewhere.