Rev August r LR - USDA · ARS soil scientist Ray Bryant (left) and UMES associate professor Arthur...

Helping Savethe Chesapeake Bay

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U.S. Department of Agriculture Agricultural Research Service August 2010

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Some locals measure water quality in the Chesapeake Bayusing the “sneaker index.” In the 1950s, Maryland residentBernie Fowler waded into the Patuxent River to his shouldersand could see his white sneakers on the riverbed. But in 1988,when Fowler, who by then was a state senator, ventured backinto the Patuxent, he could not see his nice white sneakers oncehe waded beyond 10 inches of water. It was better in 2009, whenhe could see his sneakers in 25.5 inches of water—but it’s stillnot good enough.

Agricultural Research Service scientists haven’t been watch-ing over the Chesapeake Bay quite as long as Fowler has, butthey are committed to restoring water quality in the bay. This iswhere bald eagles patrol the marshes, American oystercatcherspace the beaches and tidal flats, bottlenose dolphins cruise off-shore waters, and crabs with bright blue claws swim sidewaysthrough the shallows. And the famed eastern oysters that clusterin massive aquatic reefs double as water-treatment plants—anindividual bivalve can filter sediments, algae, and pollutantsfrom as much as 50 gallons of water every day.

But the oysters can’t keep up with current challenges. In 2006,about 16.6 million people lived in the bay watershed (see mapof watershed on page 5), where the demand for surface- andground-water supplies continues to grow. At the same time,water sources are contaminated by sewage, sediment, fertilizerrunoff from suburban lawns, and expired medications that arepoured down drains throughout the six states in the ChesapeakeBay Watershed.

Agriculture is another major factor in the bay’s health. Poultryproduction on the Eastern Shore is an economic mainstay, butnutrient-rich runoff from poultry litter flows into the creeks anddrainage ditches that feed the bay. The runoff prompts growthof algae and other plants, and when the vegetation dies, itsdecomposition robs those waters of oxygen essential to otheraquatic life. Sediment and excess fertilizer from crop fields canalso eventually migrate into waterways that feed into the bay.

None of this is news. Over the years, a range of state, federal,local, and nonprofit groups have put their best efforts towardstemming water pollution and restoring bay habitats. There’sbeen some progress, but not enough.

So what happens now? And how will ARS be involved?On May 12, 2009, President Barack Obama signed Execu-

tive Order No. 13508 for the Chesapeake Bay Protection andRestoration, which directed federal agencies to increase theircooperation and collaboration in a concerted effort to clean upthe bay. ARS scientists will carry out the President’s mandate by

strengthening their current research and continuing to forge newcollaborative efforts with other federal agencies. These partner-ships will allow ARS to more fully address the environmentalissues presented by the bay’s complex landscape—a mix of cropfields, pastures, forests, wetlands, and urban and suburban areas.

For instance, since 2004,ARS scientists in Beltsville, Maryland,have been leading the Conservation EffectsAssessment Project’sWatershed Assessment Study of Maryland’s Choptank RiverWatershed (see article beginning on page 10). Their long listof county, state, federal, university, and local partners reflectsjust how vital these studies are to understanding the watershedprocesses that affect water quality in the bay.

ARS scientist Greg McCarty and USDA Forest Serviceecologist Megan Lang are using remote sensing to map forestedwetlands in the Chesapeake Bay Watershed (see page 13).They’ve increased the accuracy of wetland maps by around 30percent and developed techniques to track temporal variationsin wetland flooding and soil moisture. McCarty is also workingwith U.S. Geological Survey physical scientist Dean Hively touse remote sensing to monitor the effectiveness of winter covercrops in sequestering nitrogen, which will support Maryland’scover crop cost-share programs (see page 16).

ARS scientists Laura McConnell and Cathleen Hapemanare partnering with the U.S. Environmental Protection Agencyto examine atmospheric, agricultural, and urban sources ofbay pollutants. A few hours up the road, ARS scientists atthe Pasture Systems and Watershed Management ResearchUnit in University Park, Pennsylvania, are making their owncontributions to cleaning up the Chesapeake Bay Watershed.Researchers Peter Kleinman, Ray Bryant, John Schmidt, TonyBuda, Curt Dell, and Clinton Church have teamed up withregional partners on a range of water-quality projects that start inNew York and end up on a former chicken farm on Maryland’sEastern Shore (see page 4).

At ARS, we’ll continue to do what we’ve been doing allalong: partnering with experts throughout the public and privatesectors to find new technologies and improve existing tools forcleaning up the bay one crop field, stream, wetland, and drain-age ditch at a time.

Mike Shannon, Mark Walbridge, Matt Smith,and Charles WalthallARS National Program LeadersNatural Resources and Sustainable Agricultural SystemsBeltsville, Maryland

2 Agricultural Research/August 2010

Saving the Bay: It’s One of the Things ARS Does Best

Agricultural Research is published 10 times a year by the Agricultural Research Service, U.S. Department of Agriculture (USDA). The Secretary of Agriculture has de-termined that this periodical is necessary in the transaction of public business required by law.

Tom Vilsack, SecretaryU.S. Department of Agriculture

Ann Bartuska, Acting Under SecretaryResearch, Education, and Economics

Edward B. Knipling, Administrator Agricultural Research Service

Sandy Miller Hays, DirectorInformation Staff

Editor: Robert Sowers (301) 504-1651Associate Editor: Sue Kendall (301) 504-1623 Art Director: Chip Beuchert (301) 504-1608 Photo Editor: Anita Daniels (301) 504-1609 Staff Photographers: Peggy Greb (301) 504-1620 Stephen Ausmus (301) 504-1607

Most information in this magazine is public property and may be reprinted without permission (except where copyright is noted). Non -copyrighted articles and high-resolution digital photos are available on the World Wide Web at ars.usda.gov/ar.

Paid subscriptions are available from the U.S. Government Printing Office (Superintendent of Documents). See back cover for ordering infor mation. Complimentary 1-year subscriptions are available directly from ARS to public libraries, schools, USDA employees, and the news media. Call (301) 504-1638 or e-mail [email protected].

This magazine may report research involving pesticides. It does not contain recommendations for their use, nor does it imply that uses discussed herein have been registered. All uses of pesticides must be registered by appropriate state and/or federal agencies before they can be recommended.

Reference to any commercial product or service is made with the understanding that no discri mination is intended and no endorsement by USDA is implied.

The USDA prohibits discrimination in all its programs and activities on the basis of race, color, national origin, age, disability, and where applicable, sex, marital status, familial status, parental status, religion, sexual orientation, genetic information, political beliefs, reprisal, or because all or part of an individual’s income is derived from any public assistance program. (Not all prohibited bases apply to all programs.) Persons with disabilities who require alternative means for communication of program information (Braille, large print, audiotape, etc.) should contact USDA’s TARGET Center at (202) 720-2600 (voice and TDD). To file a complaint of discrimination, write to USDA, Director, Office of Civil Rights, 1400 Independence Avenue, S.W., Washington, D.C. 20250-9410, or call (800) 795-3272 (voice) or (202) 720-6382 (TDD). USDA is an equal opportunity provider and employer.

Cover: The Chesapeake Bay’s health is in jeopardy from sediment, fertilizers, pharmaceuticals, and other contaminants coming from its 65,000-square-mile watershed. A recent Executive Order emphasized the importance of protecting and restoring the bay. ARS is partnering with experts throughout the public and private sectors to find new tech-nologies and improve existing tools for cleaning up this national trea-sure. See Forum (opposite page) and stories on pages 4-17.

31Agricultural Research/August 2010

Solving Problems for the Growing World

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There’s More Than One Way to Save the Bay

New Poultry Litter Applicator Offers Hope for Chesapeake Bay Area

ARS Chesapeake Bay Research Intensifies

Forested Wetlands in the Chesapeake Bay Watershed

Chesapeake Bay Cleanup Revs Up!

Anti-pest Aeration: A New Twist on an Old Concept

Throwing a Citrus Pest Off Its Scent

Bee Pastures: Floral Havens Where Pollinators Can Prosper

Producers and Pigs Profit From Manure Management Process

Unravelling the Origins of a Symbol of the Tropics

Stress: It’s Not Just for You and Me

Whole Tree: A More Sustainable, Environmentally Friendly Substrate Power Needs and Wind Power as Different as Day and Night

Torching Invasive Trees Revives Rangeland Perennials

Science Update

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peggy greb (D1834-2)

August 2010Vol. 58, No. 7ISSN 0002-161X

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An ARS team of scientists determined that the equivalent of 12 percent of the phosphorus load in the Town Brook Watershed—a major source of drinkingwater for New York City—came from dairy cow dung deposited directly in streams.

STEPHEN AUSMUS (D1862-22)


It’s about a 5-hour drive from the Chesapeake Bay’s EasternShore in Maryland to the Agricultural Research ServicePasture Systems and Watershed Management Research

Unit in University Park, Pennsylvania.This is where six ARSscientists are monitoring agricultural pollutants that are

washed from crop fields into groundwater and streams andeventually discharged into the bay—and they are creating

THERE’S MORE THAN ONE WAY

TO SAVE THE BAY


Chesapeake Bay Watershed map created from a satellite image.

ARS (D1890-1)


all the roadblocks they can along the way. TheARS team has beenable to work in all the major physical and geographic regions ofthe Chesapeake Bay Watershed by developing a six-state networkof collaborators.

“Some of our research is quantifying how farming contributesto nutrient runoff,” says ARS soil scientist Peter Kleinman. “Butwe’re also testing and developing new practices and strategiesfor improving the odds that plant nutrients like nitrogen andphosphorus are taken up by crops and don’t escape to the bay.”

Please Step Away From the StreambankKleinman’s work started in New York’sAllegheny Plateau (see

map), a forested expanse broken up by small dairy farms, wherethe University Park team oversees activities in the Town BrookWatershed as part of the Conservation EffectsAssessment Project(see story on page 10). Although the area is just outside of theChesapeake Bay Watershed, farming practices in the Town BrookWatershed closely resemble those across theAllegheny Plateau—the headwater region of the the Chesapeake’s watershed.

Kleinman’s team determined that the equivalent of 12 percentof the phosphorus load in the Town Brook Watershed—a majorsource of drinking water for New York City—came from dairycow dung deposited directly in streams. The findings helpedconvince local farmers to install more streambank fencing tokeep cows away from streambeds and to improve water quality.

Testing Apps in AppalachiaThe ARS team often test-drives their practices and procedures

in the Mahantango Watershed, a long-term experimental wa-tershed 2 hours southeast of University Park that is part of theAppalachian Ridge and Valley Region.

This is where soil scientist John Schmidt has been testing asensor system to help farmers fine-tune applications of nitrogento knee-high corn crops. The small sensors are mounted in frontof a tractor and measure yellow-amber and near-infrared lightwaves from the corn plants. A computer uses the data to calcu-late the amount of nitrogen that should be added to the soil andtransmits this information to the applicator, which amends thefield with the appropriate levels of nitrogen.

“If we match the amount of nitrogen that’s applied with theamount that the crop needs, then less nitrogen will be leachedout of the field—and the yields should be greater,” Schmidt says.“It’s also a way to get on-the-go recommendations for nitrogenapplications, instead of sending soil samples off for testing.”

Schmidt and University Park research leader Ray Bryantare also testing a proprietary nitrogen fertilizer formulationdeveloped in the United Kingdom. “When nitrogen is added tosoil, it’s often converted to nitrate, which is easily leached out,”Bryant explains. “But the nitrogen in the U.K. fertilizer is in aform that is available for plant uptake and can resist the microbialbreakdown that results in the conversion to nitrate.”

Bryant and Penn State colleague Max Schlossberg ran a trial ofthis fertilizer on bentgrass—a type of turfgrass used in golf coursesand residential lawns—and found they could reduce fertilizer useby 25 percent and still obtain optimum growth and performance.They now plan to test the new fertilizer on corn and other crops.

It’s All in the TimingFarmers who add manure to their fields don’t have to pay for

fertilizer and don’t have to pay to have manure hauled away. Butwhen it rains, the nitrogen and phosphorus in freshly appliedmanure can run off and pollute nearby water sources.

So ARS hydrologist Tony Buda has been working inthe Appalachian Ridge and Valley Region to build a Web-based “fertilizer forecast” for agricultural fields. Kleinman,Pennsylvania State climatologist Paul Knight, and DougMiller, who oversees Penn State’s Center for EnvironmentalInformatics, are also part of the effort. Another team member isARS agricultural engineer Gary Feyereisen, who works at theARS Soil and Water Management Research Unit in St. Paul,


ARS hydrologist Tony Buda (far left) and Penn State University climatologist Paul Knight examineregional data they are using to develop a Web-based “fertilizer forecast,” which will help farmers limitnutrient runoff by avoiding fertilizer applications before precipitation events. The program will use arange of weather variables, including the type of meteorological data Penn State associate professorDoug Miller and ARS soil scientist Peter Kleinman (far right) are studying in the background.


ARS hydraulic technician Terry Troutman collects a routine water sample in the Mahantango CreekExperimental Watershed, Klingerstown, Pennsylvania.



Minnesota. The scientists want to createa tool that produces 24-hour and 5-dayrunoff forecasts that are as user-friendlyas Web-based weather forecasts.

“We want to develop a simple hydro-logic model that indicates the probabilityof field runoff occurrence using NationalWeather Service (NWS) probabilities forprecipitation, soil moisture, and otherdata,” Buda says. “And we want some-thing that runs pretty quickly.”

The researchers are analyzing howrunoff measurements for different regionsin Pennsylvania correlate with differentNWS data sets for the same areas. Forinstance, they’ve found that soil moisturelevels are a strong indicator of nutrientrunoff potential from field soils that haverelatively impermeable subsurface soillayers. But at sites with other soil char-acteristics, runoff potential is much morestrongly associated with rainfall amountand intensity.

The Right Tools for the JobThe University Park scientists are also

helping farmers in the Conewago CreekWatershed implement best managementpractices for manure and fertilizers,including the use of cutting-edgetechnology like manure injectors. Thewatershed is located in the AppalachianPiedmont, which stretches from the easternslopes of the mountains to the AtlanticCoastal Plain and includes some of themost populated areas in the ChesapeakeBay Watershed.

As part of this work, soil scientist CurtDell is testing techniques for amend-ing soils with manure from swine andcattle. He’s trying to strike a fine balancebetween tilling manure into soils to mini-mize nutrient runoff and maintaining theenvironmental benefits of no-till farming,which leaves the soil surface undisturbedand more resilient to erosive forces.

Dell thinks manure disk injectors (seesidebar on page 9) show the most promisefor meeting these dual goals. A single diskcuts into the soil to a maximum depth of4 inches, and then a tube attached to the



University of Maryland-Eastern Shore (UMES) scientist Eric May (right) retrieves a plankton netfrom the water while Penn State graduate student Sarah Gustafson and ARS hydrologist Tony Budaconduct water-quality sampling in a tributary of Maryland’s Manokin River. These samples will beused in studies that examine whether urea pollution in the watershed is linked to periodic blooms ofphytoplankton known as Pseudo nitzschia species.

Tony Buda (right) and laboratory worker David Otto collect runoff water samples from a hillslope trenchthat is being used to monitor lateral subsurface flow pathways during and after storms.



disk injects the manure into the cut. Thisensures that there is minimal disturbanceto the soil surface, and odor emissionsdrop because the manure is added belowthe soil surface.

“Up to half of the plant-available ni-trogen is typically lost through ammoniaemissions within a few days after dairymanure is applied to fields,” Dell explains.“But when we use a disk injection systemto add manure to the fields, we can cutthose emissions by 80 percent.”

Litter’s LegacyLarge-scale poultry farming started up

on the Chesapeake Bay’s Eastern Shorein the 1920s, and now over 750,000 tonsof poultry litter and manure are producedeach year. Farmers on the Eastern Shore—part of the Chesapeake Bay’s CoastalPlain—have amended the region’s sandysoils with poultry manure and litter foryears. Nutrient levels have accumulatedin the soils, and some of the nutrients findtheir way to the bay.

“Even if we stopped fertilizing somesoils, it wouldn’t really affect how muchphosphorus is lost from them becausethey contain so much already,” says Bry-ant. “We need to deal with the legacyof past management—and that meanswe’re attacking a very difficult part ofthe problem.”

Bryant and colleague Arthur Allenfrom the University of Maryland-EasternShore (UMES) have developed a way totrap the “legacy phosphorus” from theregion’s poultry farms that leaches fromsoils to drainage ditches. Working at anexperimental farm owned by UMES—thesite of a former chicken farm—they duga trench alongside an existing drainageditch. Then they filled the trench withsynthetic gypsum, a product of scrubbingthe smokestacks of coal-fired power plantsto remove sulfur emissions.

When the groundwater passed out ofthe field and through the gypsum-filledtrench on its way to the drainage ditch, thesoluble calcium in the gypsum “captured”the soluble phosphorus in the water by




ARS soil scientist Ray Bryant (left) and UMES associate professor Arthur Allen collect samples ofgroundwater before and after it is filtered through an underground “curtain” of gypsum. The low-costgypsum curtains remove phosphorus from the groundwater before it flows into a drainage ditch,preventing the phosphorus from reaching the Chesapeake Bay.

ARS chemist Clinton Church (center) works withUMES student Betty Chumbe-Kitur (left) andother UMES students to measure arsenic levelsin water samples from Princess Anne, Maryland.


combining with it and forming calciumphosphate. Calcium phosphate is similarto rock phosphate, which is the source ofphosphates used to make fertilizer. Bryantfound that the gypsum trench could treatall the water draining from a field andreduce soluble phosphorus in subsurfacedrainage by about 50 percent.

“These gypsum ‘curtains’ are good for10 years,” Bryant says. “Then they canbe dug up, and the trapped phosphoruscan be used again for fertilizer. And thepower plants don’t have to pay to haul thegypsum to a landfill.”

ARS chemist Clinton Church is alsodealing with a legacy: arsenic.

“Although the practice is falling out offavor, historically arsenic was routinelyadded to poultry feed to control parasitesand help the birds gain weight. But 90percent of the arsenic is excreted, andwhen the litter is used to amend the soil,the arsenic ends up in the fields,” Churchexplains.

Church, Allen, and others conducteda comprehensive survey of soils aroundthe UMES Research and Teaching Farmand in forested areas around the farm andfound that virtually all of the samplescontained some arsenic. Levels were lowin the forested soils and notably higher inthe soils that were closer to the source ofthe litter, such as the shed where the litterwas stored.

“Arsenic can occur naturally in soils, sothis study is a first step to find out wherethe arsenic is and how much is there,”Church says. “But since its chemicalstructure is very similar to the chemicalstructure of phosphorus, we know it hasto be ending up in the region’s estuaries.”He is hopeful that some of the filtrationmethods Bryant is testing will also workto remove arsenic.

The Big PictureKleinman thinks the University Park

research helps provide a broader perspec-

tive on the effort that will be needed toclean up a 65,000-square-mile watershed.

“There’s a real risk of focusing on localissues to derive conclusions about what isbest for the Chesapeake Bay,” Kleinmansays. “For instance, the Eastern Shore isonly 6 percent of the Chesapeake BayWatershed, but for many people, it’s thebiggest part of the story. We need to lookat agricultural practices throughout thewatershed, because the entire watershedcontributes to the health of the bay.”—ByAnn Perry, ARS.

This research is part of Water Availabil-ity and Watershed Management (#211),Global Change (#204), and Manure andByproduct Utilization (#206), three ARSnational programs described at www.nps.ars.usda.gov.

To reach scientists mentioned in thisarticle, contact Ann Perry, USDA-ARSInformation Staff, 5601 Sunnyside Ave.,Beltsville, MD 20705-5129; (301) 504-1628, [email protected].*

STEPHEN AUSMUS (D1870-18)STEPHEN AUSMUS (D-1868-10)

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ARS soil scientist Dan Pote observes as ARS technician Stephen Haller operates their invention, thePoultry Litter Subsurfer—the first commercially viable machine for applying dry poultry litter below ground.


It isn’t even fully patented yet, but thePoultry Litter Subsurfer prototype in-vented by Agricultural Research Servicesoil scientist Dan Pote is on order by aresearch coalition across five ChesapeakeBay states: Delaware, Maryland, Virginia,Pennsylvania, and New York.

The coalition, led by ARS’s PeterKleinman and counterparts at Pennsyl-vania State University at University Parkand Virginia Polytechnic Institute andState University at Blacksburg, recentlyreceived a $786,000 Chesapeake Steward-ship Fund grant to test four prototypes ofPote’s Subsurfer in applying poultry litterand composted cattle manure to no-tillfields and pastures across the ChesapeakeBay Watershed.

Pote is at the ARS Dale Bumpers SmallFarms Research Center in Booneville,Arkansas.

ARS is applying for U.S. and inter-national patents on the equipment. Onecompany has applied for a license tocommercialize it.

The Subsurfer can carry up to 5 tonsof litter for application below the surfaceof pastures without damaging the grass,much as a no-till planter places seeds. Itcan also apply poultry litter below no-tillfields before planting.

In prior tests onArkansas pastures, Potefound that subsurface application of litterlowers nutrient runoff and ammonia emis-sions at least 90 percent, while increasingforage yields. Kleinman and colleagues atthe University of Maryland-Eastern Shoretested several versions ofARS subsurfacelitter applicators on no-till fields andpastures in Maryland and Pennsylvania,documenting lower phosphorus runoffand ammonia loss and greater corn yields.Jack Meisinger, soil scientist at the ARSHenry A. Wallace Beltsville AgriculturalResearch Center in Beltsville, Maryland,also reports lower ammonia losses fromcorn plots.

In 2009, Pote demonstrated the Sub-surfer at a Soil Conservation District/USDA Natural Resources ConservationService meeting in southern Maryland aswell as at the 31st Southern AgriculturalSystems Conference on Virginia’s EasternShore.

In spring 2010, Pote teamed up withKaramat Sistani of theARSAnimal WasteManagement Research Unit in BowlingGreen, Kentucky, to test the Subsurferon a farmer’s corn field near Owensboro,Kentucky. “This is the largest scale testwe’ve done on corn fields,” Pote says.“We are comparing the Subsurfer to thetraditional method of surface-broadcastapplication under field-scale conditions.”

As a collaborative project, Pote leddevelopment of the Subsurfer for pasturesand no-till fields, while ARS agriculturalengineer Tom Way’s team at the ARSNational Soil Dynamics Laboratory inAuburn,Alabama, focused on developinga different prototype with adjustable rowspacing for litter application in row-cropsystems and pastures.

The two machines have such differ-ent delivery systems that Pote and Waysought different patents. Pote’s Subsurferuses a unique auger system that crushes

litter and distributes it to soil trenches,allowing precise control, including verylow rates not previously feasible. Histractor-drawn Subsurfer simultaneouslyopens eight trenches (2 inches wide and3 inches deep), each 1 foot apart.

Throughout the southeastern and Mid-dle Atlantic states, poultry production isthe primary source of income for manysmall family farms. Poultry litter is anexcellent source of crop nutrients, butthe common practice of spreading it onthe soil surface promotes odor emissions,exacerbates nutrient runoff to nearby wa-terways—most notably the ChesapeakeBay, and allows ammonia nitrogen toevaporate. By minimizing nutrient losses,farmers can improve air and water qualityand increase crop productivity.—By DonComis, ARS.

This research is part of Pasture, Forage,and Range Land Systems (#215) and Wa-ter Availability and Watershed Manage-ment (#211), two ARS national programsdescribed at www.nps.ars.usda.gov.

Daniel H. Pote is with the USDA-ARSDale Bumpers Small Farms ResearchCenter, 6883 South State Hwy. 23, Boone-ville, AR 72927-8209; (479) 675-3834,ext. 344, [email protected].


New Poultry Litter Applicator Offers Hope for Chesapeake Bay Area

http://www.ars.usda.gov/is/contacts.htm#Don

http://www.ars.usda.gov/Main/docs.htm?docid=2354


USDA Forest Service ecologist Megan Lang and herpetologist Joseph Mitchell (Mitchell EcologicalResearch Services, LLC) carefully search a wetland debris sample for amphibians. Frog tadpolesare often hidden in the sample material. Inset: This adult male green frog (Rana clamitans) is acommon inhabitant of natural and restored wetlands. Biometric assessments (weight and length) ofcaptured amphibians are recorded, then they are released back into the wetlands.


The Chesapeake Bay faces many threats—from the pesticides and fertilizers usedto grow corn, soybeans, and other crops,to pollution from wastewater-treatmentplants, cars and boats, and poultryproduction.

Agricultural Research Service scientistshave contributed to the effort to clean upthe bay for more than two decades. Mostrecently, ARS scientists in Beltsville,Maryland, conducted a comprehensivestudy of pollutants at seven spots in theChoptank River, a major bay tributary thatfaces the same threats.

Traveling in a research vessel, theycollected water samples at each stop.They later analyzed these samples forsalinity, temperature, dissolved oxygen,chlorophyll, phosphorus, nitrogen,arsenic, copper, and the herbicidesatrazine, simazine, and metolachlor andtheir degradation products.

Sampling a Bay TributaryThe U.S. Geological Survey (USGS)

established some of these sampling sitesin 1975, providing long-term data forreference. The U.S. Environmental Protec-tion Agency (EPA) also has water-qualitymonitoring stations in the Choptank thatdate back even earlier.

This study was done as partof the Conservation EffectsAssessment Project (CEAP)for the Choptank River Water-shed. CEAPbegan in 2004 andnow involves 37 watershedsnationally. CEAP focuses onthe effects of USDAconserva-tion practices and Farm Billconservation programs.

The long-standing regional goal ofcleaning the bay is an additional incen-tive for success in the CEAP Choptankprogram, resulting in a network of or-ganizations ready to use ARS’s researchresults. (See list of organizations on page12 in this issue.) It also provides an es-tablished scientific infrastructure, suchas the USGS and EPA samplings sites, tosupport research.

PEGGY GREB (D1884-1)


ARS CHESAPEAKE BAYRESEARCHINTENSIFIES



ARS agronomist Peter Downey (left) and soilscientist Greg McCarty collect a water sampleon the Choptank River for pesticide and nutrientanalyses.

breakdown products and nitrates flowmainly via groundwater.

“The concentrations of herbicides weobserved did not approach establishedlevels of concern for aquatic organisms,”Hapeman says. “Still, this research showsthe importance of agricultural practicesthat reduce herbicide losses from spring-time applications in particular.”

A Clear View of the Bay“The Choptank water sampling gives

us a baseline against which to comparefuture changes in water quality,” Hape-man says. “It may also be used to designprograms to monitor the effectiveness ofrestoration efforts. Simultaneous mea-surement of multiple water-quality vari-ables and contaminant concentrations isimportant to creating a clear picture of themain water-quality problems and dynam-ics within Chesapeake Bay tributaries.”

ARS soil scientist Greg McCarty saysthat the overall goal of the ChoptankCEAP research is to “develop a set ofmeasurement and modeling tools for as-sessing the effectiveness of commonlyused conservation practices at a watershedscale. We use remote-sensing techniques

Monitoring the Choptank providesneeded information on the dynamics ofthe bay watershed. This information helpsdevelop new conservation practices orrefine existing ones.

Sampling every 2 months from March2005 through April 2008, the ARS sci-entists and their colleagues found thatnitrate concentrations, which were highestin winter, often exceeded levels that cancause algal blooms. Algal blooms candeplete dissolved oxygen concentrationsin the river, killing aquatic organisms suchas fish and shellfish. Nitrate levels werehighest at the headwaters where farming isconcentrated, suggesting that agriculturalfertilizers, including manure and poultrylitter, are the primary sources of the nitrate.

In contrast, phosphorus concentrationswere similar throughout the length of theriver, suggesting multiple sources of thisnutrient. While some evidence points towastewater treatment plants as a likelyprimary source, agriculture is also a majorcontributor of phosphorus to the bay.

Elevated copper concentrations werefound in almost all samples at the lowerreaches of the Choptank, but not in theupstream areas.

“This suggests that copper loss from an-tifouling boat paint is the primary sourceof the copper, rather than agriculture,”says Dean Hively, a visiting physical sci-entist from the USGS Eastern GeographicScience Center. “The levels were highenough to be toxic to clams and otheraquatic invertebrates that help feed andfilter the bay.”

To the Bay: Above- and Below-Ground Routes

Herbicidesand theirbreakdownproductswere present year-round throughout thestudy, says Cathleen Hapeman, a chemistat the ARS Environmental Managementand Byproducts Utilization Laboratory(EMBUL) in Beltsville, Maryland.Herbicide concentrations peaked afterspringtime applications. While herbicidesand phosphorus travel to the Choptankmainly via surface water flow, herbicide

to broaden measurements of the effective-ness of practices from one field to theentire watershed. We also do this withanother technique we developed to evalu-ate winter cover crop effectiveness.” (Seestory on page 16 of this issue.)

In another CEAP Choptank study, Mc-Carty, Hapeman, and colleagues moni-tored levels of nitrogen, phosphorus,atrazine, and metolachlor within 15 smallagricultural and forested subwatershedsof the Choptank to gain a more detailedassessment of land use and conservationpractices on water quality. For com-parison, they periodically sampled lowerportions of the river that are not borderedprimarily by agricultural land.

McCarty and ARS chemist Laura Mc-Connell are the principal investigatorsfor the Choptank project, working withHapeman,ARS soil physicistAli Sadeghi,Hively, USDA Forest Service ecologistMegan Lang, ARS agronomist EtonCodling, and ARS chemists Clifford Riceand Krystyna Bialek.

McCarty, Sadeghi, Hively, and Lang areat the ARS Hydrology and Remote Sens-ing Laboratory in Beltsville, Maryland.McConnell, Hapeman, Rice, Bialek, andCodling are with EMBUL.

Forests, Wetlands Vital to Bay’s Health

In studying nutrient and herbicide flowsfrom the 15 subwatersheds, McCarty says,“We have discovered that watershedswith more forests or wetlands export less

University of Maryland PhD student GabrielaNiño de Guzmán collects water samples forpesticide and antibiotics analyses in a streamwithin the Choptank River Watershed.






nitrate to the river.” Forests and wetlandsnaturally slow the movement of water onthe land, allowing nature to process nitrate.“This area of the bay has historically beendrained by ditches, which short-circuitthese natural filters within the landscape,”McCarty says. “Farmers can use drainage-control strategies to slow the movement ofwater from their fields, thereby restoringsome of the filtering capacity of the land.Acombination of riparian buffers, wetlands,and controlled drainage management areneeded to mitigate nutrient pollution.”

Nation’s Testing GroundARS is also working on CEAP’s re-

cently developed Mid-Atlantic wetlandsstudy, which incorporates ARS researchon wetlands in the Choptank’s watershed.The effort involves ARS laboratories inBeltsville; University Park, Pennsylvania;and Florence, South Carolina. It focuseson wetland benefits in the New Jersey,Delaware, Maryland, Virginia, and NorthCarolina Coastal Plain. The Mid-Atlanticproject provides a testing ground for anational program of monitoring wetlandsto evaluate and sustain or improve theirbenefits to society and the environment.

“Like all CEAP projects,” Lang says,“one goal of the wetlands study is to de-velop collaborations to deliver research

Chemists Cathleen Hapeman (left) and LauraMcConnell use air and rain sample collectiondevices to study the fate of atmosphericpollutants in the Chesapeake Bay region.

CEAP Chesapeake Bay Partners

• Maryland Department ofAgriculture

• University of Maryland-WyeResearch and Education Center

• University of Maryland Center forEnvironmental Science

• Smithsonian EnvironmentalResearch Center

• USDA’s Natural ResourcesConservation Service

• National Oceanic and AtmosphericAdministration

• USGS Eastern GeographicScience Center

• USDA’s Forest Service• Queen Anne’s, Talbot, and

Caroline County Soil ConservationDistrict Offices

• Local farmers

and Watershed Management (#211), andClimate Change, Soils, and Emissions(#212) four ARS national programs de-scribed at www.nps.ars.usda.gov.

To reach scientists mentioned in thisarticle, contact Don Comis, USDA-ARSInformation Staff, 5601 Sunnyside Ave.,Beltsville, MD 20705-5129; (301) 504-1625, [email protected].*

results for better practices. The resultsinform conservation decisions affectingwetland ecosystems and the servicesthey provide, such as pollution control,”she says.

Through the Choptank wetland study,Lang found that using radar sensorsaboard satellites provided a way to detectwater flows in forested wetlands. (Seearticle on page 13 of this issue.) Throughthis CEAP wetland study, new techniqueshave been developed to map and monitorwetlands. These techniques are currentlybeing explored for possible incorporationinto operational programs by multiplefederal and state agencies. Lang is nowworking with the Maryland Natural Re-sources Conservation Service to use thesetechniques to monitor the success of largeforested wetland restorations and encour-age the restoration of more wetlands.

To the Bay: By AirNewer CEAP Choptank studies are

looking at how the interplay of agricultureand urban areas affects carbon storage,wildlife habitat, and air quality.

For example, McConnell leads a newair-quality study that is the first to examineseveral types of farm emissions—am-monia; active ingredients in pesticides;volatile organic compounds from crops,solvents, and other pesticide ingredients;and dust—and their interactions with ur-ban pollutants across the bay watershed.

McConnell, Hapeman, Rice, and col-leagues at the University of Maryland-College Park are developing new tech-niques for tracking agricultural airborneparticles by their chemical fingerprints.

The vastness of the bay’s watershedmakes the task of halting the bay’s de-cline even more of a challenge. Growingurbanization makes it essential to imple-ment practices in coming years that ensurethat urban and rural communities worktogether to lower rather than increasepollution risks.—By Don Comis, ARS.

This research is part of Manure and By-product Utilization (#206), Soil ResourceManagement (#202), Water Availability

A blue heron on the Choptank River.








USDA Forest Service ecologist Megan Lang uses a global positioning system to determine an area’s exact location while ARS soil scientist Greg McCartymeasures soil moisture at the location. Information on soil moisture is used to determine the accuracy of wetland maps produced using LiDAR and radar.

FORESTED WETLANDSIN THE CHESAPEAKE BAY WATERSHED



A Tale of Two SensorsBoth SAR and LiDAR are active sen-

sors in that they transmit their own energy.Long-wavelength microwave energy isused by SAR, while shorter wavelengthlaser energy is used by LiDAR. Both sen-sors use the time it takes for the signalsto travel to the wetlands and the strengthof the returning signal to help detect thepresence, extent, and, in some cases, depthof water.

SAR is currently collected by satellite-mounted sensors, allowing for morefrequent image collections over largeareas. LiDAR sensors are usually flownon airplanes, so the imagery is collectedmuch less frequently, but it has greaterspatial resolution.

SAR is best for spotting short-termchanges in water levels, such as flood-ing or short-lived pools of water, whileLiDAR is better for producing highlyaccurate maps of flooding and under-standing the surface-water flow paths inlandscapes or recording changes over longtime periods.

A clear view through the trees. That’swhat soil scientist Greg McCarty andUSDA Forest Service ecologist MeganLang have been working towards as theypioneer the merging of two remote sens-ing technologies to map forested wetlandsin the Chesapeake Bay Watershed.

McCarty and Lang are based at theARS Henry A. Wallace Beltsville Agri-cultural Research Center in Maryland,and they conduct research on the bay’sEastern Shore, which is located on theDelmarva Peninsula that juts between thebay and the Atlantic Ocean. Delmarva isan acronym for Delaware, Maryland, andVirginia—the three states that make upthe peninsula.

The two scientists are the first to applyLiDAR (light detection and ranging) toforested wetland mapping. They are alsoamong the few researchers to report com-bining the laser technology with a similartechnology, a form of radar (radio detec-tion and ranging) that relies on advancedtechnology called a “synthetic apertureradar” (SAR) sensor.

SAR sensors are not restricted by cloudsor even most rainstorms. That is importantwhen collecting data during rainy periods,when wetlands really show up. The im-agery also makes it practical to monitorwetlands year-round, day or night.

Both LiDAR and SAR can literally seethe wetlands through a forest canopy. Mostbay-area wetlands are forested, as are halfof the wetlands in the United States.

The sensitivity of radar’s microwavesto water makes SAR ideal for detection ofhydrologic patterns in wetlands, althoughthis research demonstrates that LiDAR isalso up to the task—and with even greaterspatial resolution.

More Accurate Wetland MapsWith the synergy between the two

sensors, McCarty and Lang have createdwetland maps that are about 30 percentmore accurate than existing maps thatuse aerial photographs, a standard methodfor wetland mapping. This synergy alsomade it possible for them to develop newtechniques to monitor wetland floodingand soil moisture as it varies throughtime. This information can be used tomap wetlands and estimate the ecosystemservices that wetlands provide society—such as filtering out pollutants, controllingfloods, cycling nitrogen and othernutrients, storing carbon, and providingwildlife habitat.

“The combined sensors can greatly im-prove understanding of ecological servicesthat wetlands provide and will likely havebearing on the management and conserva-tion of wetland ecosystems in agriculturallandscapes nationally,” McCarty says.

Together, the two sensors can detectwetlands and identify their ecologicalbenefits. As one example, Lang points tocombined LiDAR/SAR maps that showwater flow: In one part of the map, thesurface water is flowing into a ditch andthen into the Choptank River—a majorChesapeake Bay tributary—with littlefiltering of pollutants. To the right of thatarea, water flows into a forested wetland,where nutrients, sediments, and pesticides


Megan Lang and University of Maryland graduate student Robert Oesterling compare forestedwetland maps for relationships between low (blue) and higher (white) elevations on one map andwet (red) and drier (white) spots on the other map. The maps were created with two remote-sensingtechnologies, one using laser light (LiDAR, or light detection and ranging), the other radio waves(SAR, or synthetic aperture radar).



may be removed before entering theriver. Lang can even track how well theseforested wetlands can remove pollutantsthrough time. This information would nothave been available from less advancedimages, like aerial photography.

Wetlands Not Separate After AllCombining SAR and LiDAR gives such

a clear view of wetlands that McCarty andLang have found that many depressionalwetlands on the Delmarva Peninsula areoften connected to each other, to water-ways, and to the bay by an intricate net-work of other wetlands, drainage ditches,intermittent streams, and ponds. Langand McCarty have mapped networks thatcarry water and possibly pollutants to theChoptank River.

Many of these depressional wetlandswere thought to be hydrologically isolatedfrom each other, from perennial streamsand rivers, and from the bay, so the CleanWater Act did not offer them the sameregulatory protections as other wetlands.

The advent of new technology has madethis work possible. LiDAR topographic

mapping is spreading from state to state.New LiDAR and SAR sensors are beingdeveloped, along with advanced computersoftware and models to process data. Thefine-resolution LiDAR data that is used byMcCarty and Lang was provided by theCanaan Valley Institute in Morgantown,West Virginia, in partnership with theARSPasture Systems and Watershed Manage-ment Research Unit in University Park,Pennsylvania. These two organizationsare currently working with McCarty andLang to extend LiDAR to other applica-tions, including the prediction of in-fieldsoil moisture variations.

Chesapeake Bay Watershed Is Test-Bed for Improved Wetland Monitoring

The scientists are working with USDA’sNatural Resources Conservation Servicein the Choptank River Watershed as partof the Mid-Atlantic USDA Wetland Con-servation EffectsAssessment Project. Thisproject is a test-bed for new landscape-monitoring tools and technologies that willbe used for national applications. It partlyfunds Lang’s and McCarty’s research.

The flat topography of the ChoptankRiver Watershed causes poor drainage, sofarmers have built an extensive networkof drainage ditches.

Lang says, “Until recently, people havenot fully appreciated the valuable serviceswetlands provide to society, and this hasled to the loss of vast areas of wetlands.Maryland has lost about 75 percent of itswetlands, and we estimate that the Chop-tank Watershed has lost well over halfof its historic inland wetlands. But thewetlands that remain serve critical rolesin maintaining water quality, regulatinggreenhouse gases, and providing habitat.The information that SAR and LiDARprovide can be used to best manage thenative wetlands that remain and reduce theimpact of agriculture on the bay.”

The maps created by McCarty andLang show changes in wetlands causedby ditches, other construction, farming,and weather. By tracking the impact of

extreme weather on wetland water levels,they can predict how climate change willaffect wetlands and their ability to providevital services, like improving water qual-ity, in the future. In this way, the mapsalso help identify how these changes mayaffect the health of the bay.

LiDAR can also be used to create digi-tal elevation models. These maps have athree-dimensional-like effect, showinglikely flow paths and where water maypool. The maps are accurate for elevationdifferences as small as 6 inches. Thesesmall differences can add up to big chang-es in flat landscapes like the Delmarva.

Even Bare Trees Block Aerial Views“With aerial photography, it’s almost

impossible to see wetlands when decidu-ous trees have leaves, and it’s very difficultto see many types of wetlands even whenthe leaves are gone. The tree branches andtheir shadows are often enough to hidewet soil, ditches, and ephemeral streams,”Lang says.

With the combined sensors, the “view”through the trees is so thorough that it even“sees” wildlife habitat, such as small poolsthat form each spring where many inver-tebrates spawn, including endangeredspecies. These vernal pools serve as ref-uges for other animals, such as frogs andtoads. The pools also help maintain uniquevegetation—even endangered plants—byproviding moisture for seed germination.

The research adds vital information tothe Chesapeake Bay cleanup and state andnational wetland regulation debates.—ByDon Comis, ARS.

This research is part of Water Avail-ability and Watershed Management, anARS national program (#211) describedat www.nps.ars.usda.gov.

Gregory W. McCarty and MeganLang are at the USDA-ARS Hydrologyand Remote Sensing Laboratory, Bldg.007, Room 104, 10300 Baltimore Ave.,Beltsville, MD 20705; (301) 504-7401[McCarty], (301) 504-5138 [Lang], [email protected], [email protected].*


Using a global positioning system, ARS soil scientistGreg McCarty locates a wetland study site.



http://www.ars.usda.gov/main/site_main.htm?modecode=12-65-06-00

mailto:[email protected]






President Barack Obama’s May 12, 2009,Executive Order on Chesapeake Bay Pro-tection and Restoration directed federalagencies to clean up the bay and to pro-mote reliance on adaptive management toincrease environmental benefits.

This management approach meansusing ecosystem monitoring, with rapidfeedback, for improved decisionmakingin managing land to reduce pollution ofthe bay.

The Agricultural Research Service’smerging of remote-sensing, field-sampling, and farm-program records tojudge the effectiveness of winter covercrops in controlling nitrogen losses fromfields fits the bill in several ways. It isthe type of use of advanced monitoringtools the order calls for, with many rapidfeedback loops to allow adjustments eachfall, when winter cover crops are plantedin the bay area. Winter cover crops are animportant practice for capturing nitrogenleft over from fall-harvested crops beforeit can pollute the bay.

Promoting Successful Cover Crop Solutions

In a 4-year study using this combinationof remote-sensing tools, Greg McCarty, asoil scientist at the ARS Hydrology andRemote Sensing Laboratory (HRSL) inBeltsville, Maryland, and Dean Hively,now a visiting physical scientist fromthe U.S. Geological Survey Eastern Geo-graphic Science Center, showed that, ofthe predominant winter cover crop speciesplanted in Maryland—rye, barley, andwheat—wheat is by far the least efficientat taking up nitrogen because of its slowfall growth. Yet 60 percent of the landplanted to cover crops is in winter wheat.The State of Maryland pays farmers toplant cover crops, with a premium forearly-planted and nonwheat crops.

McCarty and Hively also used the toolsto calculate that it costs taxpayers about$9 for each pound of nitrogen sequesteredby winter wheat, while it only costs $2.50per pound of nitrogen for rye and $3.50for barley. These calculations will be

ARS soil scientist Greg McCarty (right) and Dean Hively, a physical scientist with the U.S.Geological Survey, sample plant biomass and soil nitrogen on a cover crop field in the ChoptankRiver Watershed.


CHESAPEAKE BAYCLEANUPREVS UP!



ies, such as the Choptank River. But water-quality measurements often reflect pastmanagement, because it can take 30 yearsor more for nitrogen and other pollutantsto filter through the soil to groundwaterand resurface in a stream on the way to ariver and the bay.

Faster Feedback“The ARS program provides rapid—

rather than decades-old—feedback so thatthe annual effects of practices such as cropchoice, planting technique, and timing canbe seen and corrected the next season, ifneeded,” Hively says.

Participating scientists also includeHRSL soil scientist Ali Sadeghi, USDAForest Service ecologist Megan Lang,and chemist Laura McConnell, from theARS Environmental Management andByproduct Utilization Laboratory inBeltsville.

Maryland doubled its budget for itscover crop cost-share program to $18million in 2008-2009 and budgeted $12million for 2009-2010. This year, farmersenrolled 330,500 acres in the program.

But how much nitrogen loss do thesecover crops prevent? The answer will beprovided annually on a local basis usingthis project’s innovative combinationof remote sensing, farm-managementrecords, and field sampling.—By DonComis, ARS.

This research is part of Water Availabil-ity and Watershed Management (#211), anARS national program described at www.nps.ars.usda.gov.

To reach scientists mentioned in thisarticle, contact Don Comis, USDA-ARSInformation Staff, 5601 Sunnyside Ave.,Beltsville, MD 20705-5129; (301) 504-1625, [email protected]. *

Greg McCarty (left), Royden Powell (center), assistant secretary, MarylandDepartment of Agriculture, and Dean Hively review fields in the ChoptankRiver watershed that are enrolled in the winter cover crop program.

ing on a watershed scale,with analysis pertaining toall farms participating inthe cost-share program forwinter cover crops.

Farm Records Give Realistic View

“Another unique feature of this pro-gram is that, unlike most remote-sensingspecialists and computer modelers, wehave access to on-the-ground agronomicmanagement data on a field-by-field ba-sis,” says Hively. “For example, the farmcost-share records tell us what variety ofcrop was planted, on what date, using whatmethod, following what summer crop.This information can be combined withremote sensing to evaluate the outcomesof various management strategies used byfarmers, while maintaining farm privacy.”

The interagency research team, led byMcCarty and Hively, works closely withthe MDAOffice of Resource ConservationOperations, which manages the cover cropcost-share program.

Says Royden Powell, MDA assistantsecretary, “Cover crops are our top priorityfor controlling nitrogen and phosphorusflows to the bay. The remote-sensing tech-nology to identify crops and their growthprogress from space has been developedand perfected over the past 5 years. Com-bining remote sensing with farm recordsand field sampling gives us more exactinputs for the Chesapeake Bay model.”

The cover crop project is an outcome ofthe Choptank River Conservation EffectsAssessment Project. (See story, page 10.)

In addition toARS funds, the cover cropproject is also supported by $1.3 millionin Chesapeake Bay program watershedgrants administered by the National Fishand Wildlife Foundation. These fundsare used for research and to increasecost-share funding, accounting for theplanting and evaluation of 13,000 acresof cover crops.

“Business as usual” meant judging baycleanup progress through water-qualitymeasurements of the bay and its tributar-

made each year on a field-by-field basis,and will also include analysis of plantingtechniques and time of planting.

Every year, the ARS scientists look atcost-share program enrollment records tolocate all cover crop fields in their East-ern Shore study area. In late December,the scientists acquire satellite imageryof the fields to measure fall cover cropgrowth and again in March to measurespring growth. Simultaneous with satelliteimagery acquisition, the scientists hand-sample 30 cover crop fields to calibrate thesatellite-derived measurements.

Pilot Project for Cover Crop Monitoring

The scientists are developing GIS(geographic information system) softwareto automate cover crop monitoring andmanagement reporting. A prototype pack-age goes operational this year with a pilotproject in Talbot County, Maryland. Everyparticipating farmer will receive a field-by-field report of cover crop performance,as well as a county summary report. Soilconservation district offices will then beable to evaluate underperforming fields tostrategize for improved implementation inthe coming year. With success, the projectwill be scaled up to each of Maryland’s 24soil conservation districts.

The scientists are also developing soft-ware to summarize the data by countyand watershed and produce reports tothe Maryland Department of Agriculture(MDA). This is part of the feedback sys-tem, leading to potential adjustments infederal and state conservation programimplementation strategies.

“This represents a shift from modelingto actual measurement of conservationpractice performance, with tabular sum-maries of cover crop nitrogen uptake andassociated costs made available at countyand watershed levels, in a timely fashion,”McCarty says.

In the past, scientists and managers hadto rely on cover crop performance dataderived from plot-scale research. The newtechnique allows performance monitor-





Aeration—blowing ambient air through storage bins using lowairflow rates—has been used in commercial and on-farm storagesince the 1950s to maintain the quality of grain by keeping it cool.In Kansas and other south-central states, aeration is also usedto manage insects in stored wheat. This is achieved by coolingthe grain to 60°F or below, a temperature range that slows theactivity of most stored-product insect pests.

But few recent studies have been performed to examinewhether it’s better to direct air from above or below as a meansof using temperature to control insects, according to entomolo-gist Frank Arthur and agricultural engineer Mark Casada, bothwith ARS’s Center for Grain and Animal Health Research inManhattan, Kansas.

To find out, they used bins located at the ARS center to com-pare “pressure aeration”—which uses fans to push ambient airfrom the bottom of grain storage bins upwards, and “suctionaeration,” which involves reversing the fans to pull air from thetop downward. They conducted two 8-month trials using 6 metalstorage bins with perforated floors and grain-storage capacitiesof 1,250 bushels of wheat.

Three bins used pressure aeration, and three used suctionaeration. Devices called “anemometers” measured airflow rates,while temperature readings were taken with data loggers attachedto special sensor cables pushed to various depths and locationswithin the stored wheat. Eighteen-inch-long pitfall probe trapsmonitored the number, location, and species of grain-infestinginsects in the top surface of the wheat mass. These includedrusty grain beetles, foreign grain beetles, hairy fungus beetles,red flour beetles, sawtoothed grain beetles, rice weevils, andlesser grain borers.

Data analysis showed that, during summer months, suctionaeration cooled the stored wheat’s upper portion—dubbed the“surface zone”—more quickly than pressure aeration and thatthis difference correlated to fewer insects in the surface zone.For example, pitfall trap data for rusty grain beetles collectedover 5 sampling dates revealed 3,290 in pressure-aeration binsversus 662 in suction-aeration ones. Fewer red flour beetles wereobserved too: 8,210 trapped in pressure-aeration bins versus 722in suction-aeration bins. With a few exceptions, these reductionsalso held true for other species.

Suction aeration’s rapid cooling of the grain’s surface zone(about 1 foot deep) is advantageous, the researchers note, be-cause that’s where insects initially infest the grain after flyingin from outside.

The studies reaffirm earlier Manhattan research that aeratingbins using three temperature cycles—75°F in the summer, 60°Fin early autumn, and 45°F in late autumn—reduced insect popula-tions in experimental bins compared to using two autumn aerationcycles at 60°F and 45°F— the standard practice in south-centralstates where wheat is harvested in June or July.

Though larger-scale aeration studies are needed, “One benefitcould be reduced reliance on the fumigant phosphine for controlof insect pest populations,” Arthur and Casada write in a papercurrently in press in Applied Engineering and Agriculture.—ByJan Suszkiw, ARS.

This research is part of Crop Protection and Quarantine, an ARSnational program (#304) described at www.nps.ars.usda.gov.

To reach scientists featured in this article, contact Jan Suszkiw,USDA-ARS Information Staff, 5601 Sunnyside Ave., Beltsville,MD 20705-5129; (301) 504-1630, [email protected]. *

SUCTION versus PRESSURE AERATION

Suction (downflow)

Fan Fan

Vent

Pressure (upflow)

Cool AirWarm Air

Grain

Anti-pest Aeration: A New Twist on an Old Concept

C. BEUCHERT/ARS

http://www.ars.usda.gov/is/contacts.htm#Jan


1Agricultural Research/August 2010 19

ARS research leader David Hall (left) observes as entomologist Stephen Lapointe applies a formulation of SPLAT containing the sex pheromone of the citrus leafminer.


A 1-gram dollop of SPLAT containing the sex pheromone to disrupt citrus leafminer mating.


developed treatments that throw males off the scent of fertile females in orchards and fields. The technique has been used to control gypsy moths, codling moths, and several other pests that attack fruit and vegetable crops. These treatments are con-sidered environmentally friendly because they reduce the need for insecticides and are designed to target specific pests. “In all of them, we are basically just interfering with the male’s ability to receive the signal from the female,” Lapointe says.

Lapointe is working with Lukasz Stelinksi of the University of Florida’s Citrus Research and Education Center to see whether they can disrupt leafminer mating by manipulating either of two compounds—a triene and a diene—used by female leafminers to attract mates.

The researchers are trying to see wheth-er they can disrupt leafminer mating by manipulating either of two compounds-a triene and a diene-used by female leafmin-ers to attract mates. They also wanted to see what formulations would be most ef-fective at confusing males and disrupting their ability to pick up the female scent.

The researchers created synthetic fe-male-scented traps, placed them in a citrus grove, and counted the number of males caught. They confirmed that the three-to-one ratio of triene to diene worked better than triene or diene alone as an attractant. In 2.5 months, more than 48,000 males were captured in traps baited with the 3:1 blend compared with around 3,500 males

A citrus leafminer larva creates a gallery, or mine, within a citrus leaf, thereby gain-ing protection from externally applied pesticides and leaving behind a fecal trail. The wound created by the larva also makes the plant more susceptible to citrus canker disease. Agricultural Research Service scientists are working on controlling a pest that poses an increasing threat to Florida citrus groves by exploiting the insect’s own reproductive habits.

The leafminer moth, Phyllocnistis citrella, forms channels as it feeds inside citrus leaves and, as a result, often makes the plant more susceptible to canker dis-ease. Further exacerbating the leafminer problem is the spraying of more insecti-cide to combat another pest—the Asian citrus psyllid. The insecticide is killing off the leafminers’ natural enemies, allowing the pest to increase in numbers.

Commercial traps can sometimes help, but Stephen Lapointe, an ARS entomolo-gist with the U.S. Horticultural Research Laboratory in Fort Pierce, is exploring a control strategy that has proved effective with other pests: mating disruption. He is collaborating on the project with geneticist Randall P. Niedz and ecologist Terence J. Evens, ARS researchers at the Fort Pierce lab, and with Lukasz Stelinksi of the University of Florida’s Citrus Research and Education Center. The experimental design and data analysis were handled by Niedz and Evens, who applied advanced statistical approaches that they have been developing for resolving the effects of different kinds of mixtures in complex biological systems.

Many insects release pheromones to attract mates. In some cases, scientists have synthesized those pheromones and

captured in traps baited with the triene and only 70 in traps baited with the diene.

In a second phase of the project, the researchers surrounded the female-scented traps with 17 different combinations of the two synthetic compounds—as well as each compound on its own—to see which would be most effective at prevent-ing males from finding the traps. They placed the experimental treatments around female-scented traps at different points in-side a 59-acre grove of grapefruit trees. If the experimental treatments prevented the males from reaching the female-scented traps, the males theoretically would be unable to find females in natural settings, the researchers say. They used a waxy substance known as “SPLAT” that slowly released the experimental treatments over time, and they checked once a week over several months to see which treatments were most effective at keeping leafminers out of the female-scented traps.

Results showed that either compound used alone was as effective as the 3:1 blend at keeping male leafminers away from the female-scented traps. The diene-only treatment resulted in an 89-percent reduction in moth catches, and the triene-only treatment resulted in an 83-percent reduction. Greater amounts of diene are required to disrupt the moths, but diene is also much cheaper to synthesize, Lapointe says.

The work was recently published in the Journal of Chemical Ecology. Lapointe is also working with ISCA Technologies, Inc., of Riverside, California, a manu-facturer of the SPLAT technology, to use these results to develop a marketable leafminer mating-disruption technol-ogy.—By Dennis O’Brien, ARS.

The research is part of Crop Protec-tion and Quarantine, an ARS national program (#304) described at www.nps.ars.usda.gov.

Stephen Lapointe is in the USDA-ARS Horticultural Research Laboratory, 2001 South Rock Rd., Fort Pierce, FL 34945; (772) 462-5914, [email protected]. *

Throwing a CITRUS PEST


Off Its Scent

http://www.ars.usda.gov/research/programs.htm



http://www.ars.usda.gov/is/contacts.htm#Dennis







California bluebell (Phacelia campanularia)

Baby blue eyes (Nemophila menziesii) Lacy (or tansy) phacelia (Phacelia tanacetifolia)

Chinese houses (Collinsia heterophylla)

Today, millions of bees are needed, every year, to pollinateorchards and fields. Planting pastures for native blue orchardbees, for instance, could help meet that need. Cane estimates that,under good conditions, blue orchard bee populations could “in-crease by as much as four- to fivefold a year” in a well-designed,well-managed bee pasture.

Cane gives this brief explanation of how the pasture ideawould work: Blue orchard bees would be taken out of a beemanager’s winter storage and brought to the pasture, wherethey would emerge from their cocoons, mate, and, if female,lay eggs, before dying.

The following year, some of the new generation of bees thatdeveloped from those eggs would be brought to commercialalmond orchards to pollinate the trees’cream-white blooms. Butmost of that generation would be returned to their parents’pastureto produce yet another, hopefully larger, generation.

Beautiful wildflowers, perhaps as alluring to bees as they are topeople, might someday be planted in “bee pastures.” These floralhavens would be created to help propagate larger generations ofhealthy, hard-working bees.

Pesticide-free bee pastures can be “simple to establish and—atperhaps only a half-acre each—easy to tend,” says entomologistJames H. Cane. He’s with the Agricultural Research Service’sPollinating Insects Biology, Management, and SystematicsResearch Unit in Logan, Utah, about 80 miles north of SaltLake City.

Cane has conducted bee-pasture-related experiments for about4 years, working both in a research greenhouse and at outdoorsites in Utah and California. He says species of pastured pol-linators could include, for example, the blue orchard bee, Osmialignaria. This gentle bee helps with pollination tasks handledmainly by the nation’s premier pollinator, the European honeybee, Apis mellifera.

Bee Pastures: Floral Havens Where Pollinators CJIM CANE (D1843-1) JIM CANE (D1845-1)

JIM CANE (D1846-1)

JIM CANE (D1842-1)

JIM CANE (D1847-1)

Blue orchard bee on a California five-spotflower (Nemophila maculata)







Ideally, this cycle would continue year after year, with eachyear’s new generation larger than the one it replaced.

Best Bets for a Bountiful Bee PastureIn their experiments, Cane and colleagues have studied

wildflowers that might be ideal for planting at bee pasturesin California. In particular, the team was interested in early-flowering annuals that could help bolster populations of blueorchard bees needed for pollinating California’s vast almondorchards. The research resulted in a first-ever list of five top-choice, bee-friendly wildflowers for tomorrow’s bee pastures inalmond-growing regions.

These native California plants are: Chinese houses (Collinsiaheterophylla), California five-spot (Nemophila maculata),baby blue eyes (N. menziesii), lacy or tansy phacelia (Phaceliatanacetifolia), and California bluebell (P. campanularia).

Though blue orchard bees gathered nectar and pollen fromall of these species—a key requirement for wildflowers on thelist—the bees’obvious favorite was the bright-pink blossoms ofthe Chinese houses plants.

Wildflower species had to have more attributes than merelyappealing to bees, however. Cane’s team made sure that each ofthe select species flourishes in the same climate and soil as thatof almond orchards, and that the wildflowers bloom at about thesame time of year as those trees.

These features help make it feasible and practical for bee man-agers who are busy fulfilling a commercial almond pollinationcontract to—at the same time—manage a bee pasture.

The wildflowers also met other criteria: They are rich in pol-len and nectar and are reasonably easy to grow. And their seedis commercially available.

There was yet more that the researchers determined beforedeciding that the wildflowers were pasture-perfect. For example,the scientists either newly determined or confirmed the amountof pollen and nectar produced by the plants, and they noted thetiming and duration of the bloom. They estimated how manyflowers were produced per acre, then calculated the “carryingcapacity” of each species, that is, the number of blue orchardbees that these plants could nourish.

Cane estimates that every 10 square yards of pasture that isplanted with a mix of these five attractive flowers could provideenough pollen and nectar to support 400 mother bees. In turn,these pastured parents could produce enough progeny to—thefollowing year—pollinate 3 acres of almond trees.

Two bee businesses in California are already using the find-ings to propagate more bees, Cane notes. He collaborated in theresearch with support scientist Glen Trostle at Logan; formerLogan technician Stephanie Miller; AgPollen LLC colleagueSteve Peterson, and others.ARS and the Modesto-basedAlmondBoard of California funded the studies.

Cane notes that the bee-pasturing approach could perhapsbe developed for other regions where other tree crops that blueorchard bees pollinate are grown, such as the cherry, apple, orpear orchards of the Pacific Northwest.

Bee pasturing isn’t a new idea. But the studies by Cane andhis collaborators are likely the most extensive to date.

For the foreseeable future, bees will remain in great demand.And the bee pastures that Cane proposes are in perfect harmonywith the pollination needs of almond blossoms and wildflowersalike.

“Bee pasturing,” he says, “is an efficient, practical, environ-mentally friendly, and economically sound way for bee managersto produce successive generations of healthy young bees.”—ByMarcia Wood, ARS.

This research is part of Crop Production, an ARS nationalprogram (#305) described at www.nps.ars.usda.gov.

James H. Cane is in the USDA-ARS Pollinating Insects Biol-ogy, Management, and Systematics Research Unit, 5310 OldMain Hill, Logan, UT 84322; (435) 797 3879, [email protected]. *

rs Can Prosper

Entomologist James Cane examines wildflowers in a Logan, Utah, test plot.


7818August_r.indd 21 7/19/10 12:18 PM

http://www.ars.usda.gov/is/contacts.htm#Marcia






For almost 10 years,Agricultural ResearchService (ARS) soil scientists MatiasVanotti and Ariel Szogi have worked withfarmers, state agencies, and businesses toimprove swine manure management prac-tices. Now the scientists have developed astreamlined system that delivers a winningtrifecta—healthier pigs, healthier profits,and a healthier environment.

A key factor in this success? “We paidlots of attention to what farmers andindustry were telling us,” says Vanotti,who works with Szogi at the ARS CoastalPlains Soil, Water, and Plant ResearchCenter in Florence, South Carolina.

Manure can be used to fertilize crops,but excess nitrogen and phosphorus thatis not taken up by plants can be carriedaway by water and end up polluting nearbystreams, lakes, and groundwater. Control-ling pathogens, odors, and emissions ofammonia and greenhouse gases is alsoa concern with livestock production. Soswine producers in North Carolina—whoin 2008 sent close to 20 million pigs tomarket—are always on the lookout forways to reduce the environmental impactof their facilities.

Vanotti and Szogi have been essentialpartners in this search. In 2005 theyunveiled a first-generation swine manuremanagement system created in partner-ship with Terra Blue, Inc., a privatebusiness based in Clinton, North Carolina.(See “Blue Lagoons on Pig Farms?”Agricultural Research, March 2005.)

Taking It to the Next LevelWhen Vanotti and Szogi started out, the

technology available to them resulted in ahighly effective first-generation treatmentsystem. But the results from their farm-scale trials and new discoveries suggestedthat they could design an even more eco-nomical and simple process.

An added incentive: In 2007, the State ofNorth Carolina started a statewide LagoonConversion Program (LCP) that providedfinancial support to livestock farmers whoinstalled new manure management tech-nologies that improved water and air qual-

ARS soil scientists Matias Vanotti (left) and Ariel Szogi (right) and Lewis Fetterman, the CEO of TerraBlue, Inc., examine swine wastewater before (dark liquid) and after (clear liquid) treatment in thesecond-generation system they invented.


Producers and Pigs Profit From Manure M

http://www.ars.usda.gov/is/AR/archive/mar05/pig0305.htm


Close-up of piglet and sow.


ity. The LCP set clearly defined targets fortechniques that would meet their criteria ofan Environmentally Superior Technology(EST) for manure management.

An EST needed to eliminate dischargeof animal waste to surface waters andgroundwater. It also needed to “sub-stantially eliminate” emissions of am-monia and odors detectable beyond theproduction facility. An EST would alsosubstantially eliminate the release ofdisease-transmitting vectors and patho-gens as well as nutrient and heavy metalcontamination of soil and groundwater.And an EST would need to run economi-cally and efficiently.

The scientists’ system already met theenvironmental targets. “We needed todemonstrate that we could cut costs whilemaintaining the efficiency of the first-generation system,” Szogi says.

So Vanotti and Szogi went back to thedrawing table and worked with LewisFetterman, the chief executive officer ofTerra Blue, Inc., to redesign and fine-tunethe process. In the end, the team made 24changes to the first-generation system tolower its installation and operating costsand improve its reliability.

A U.S. Patent was granted for this newsystem (U.S. Patent 7,674,379, March 9,2010).

The on-farm system used solid-liquidseparation and nitrogen and phosphorusremoval processes. In the right combina-tion, these systems replaced traditionalanaerobic lagoon systems with a processthat produced clean, deodorized, and dis-infected effluent.

After processing, the nutrient-rich sol-ids were transported off-site to a centralcomposting facility that produced class Acomposted materials for making organicplant fertilizer and plant growth media.

The team reduced the solid-liquid sepa-ration operation from 7 days a week to just2. Several other adjustments were alsomade to this process, including simplify-ing the equipment used in the dewateringprocess and the production of drier solids.This improved solids handling, lowered

transportation costs, and made the solidsmore suitable for composting. It also in-creased their potential for use as fuel foron-farm energy generation by thermaltechnologies.

To cut costs further, Vanotti and Szogiremoved two tanks from the biologicalnitrogen removal process and incorporateda high-performing nitrifying bacterialsludge (HPNS), which they developedover 10 years in the laboratory. The newHPNS was well adapted to operate effi-ciently in both high-ammonia wastewaterand cold temperatures, which translatedinto a smaller plant footprint. It also re-duced the cost of ammonia removal.

A U.S. Patent Application was filed forthe HPNS (Serial No. 12/495,958, July1, 2009).

Finally, the scientists invented a simpli-fied process to simultaneously separate thephosphorus and the manure solids. Thisinnovation required fewer polymers thanthe previous separation system and alsoreduced equipment costs.

The revamped system was tested for15 months on a 5,145-head swine farmover 4 growing cycles. For this full-scaleproject, they collaborated with microbi-ologist Patricia Millner, who works at theARS Environmental Microbial and FoodSafety Laboratory in Beltsville, Maryland,

Using a deep sampling probe, Ariel Szogi inspects the amount of calcium phosphate produced ina phosphorus-separation module that is part of the new system.


and chemist John Loughrin, who works atthe ARS Animal Waste Management Re-search Unit in Bowling Green, Kentucky.

The results: the revamped system metEST standards at one-third the cost of theprevious version. In cleaning up manurewastewater, the system removed almost100 percent of pathogens and odor-causing components, 95 percent of totalphosphorus, 97 percent of ammonia, andmore than 99 percent of heavy metalscopper and zinc.

The new system also cut emissions ofmethane and nitrous oxide—powerfulgreenhouse gases—by 97 percent. In ad-dition, the system transformed the old la-goon into an aerobic reservoir that reduced90 percent of the ammonia emissions.

The second-generation system usedless energy to boot—power consumptiondropped by 44 percent. The newer systemwas also more labor efficient and easierto operate than the first system, in partbecause of the development of operationpractices that integrated automation withsimple operator input.

e Management Process

SCOTT BAUER (K7623-1)

http://www.ars.usda.gov/is/graphics/photos/aug10/k7623-1.htm



After processing, the nutrient-rich solids are transported off-site to a centralized composting facility.The composting process results in materials with an earthy scent and rich texture that can be usedin organic fertilizers, soil amendments, and potting soils.

Matias Vanotti and C. Ray Campbell, vicepresident of research and development, TerraBlue, Inc., examine a compost sample.

Payback TimeAll told, the second-generation technol-

ogy was two-thirds less expensive to buildand operate than the first system. WhatVanotti and Szogi didn’t anticipate is howwell the animals would respond.

But Billy Tyndall, the farmer whoowned the facility where the second-generation system was being tested, beganto notice an improvement in his pigs im-mediately after the system was installed.“The animals were heavier,” Szogi says.“And they were showing a better conver-sion of feed.”

The scientists and Tyndall were soimpressed that they extended the proj-ect—originally planned for 5 months—torun for another year and a half to see if theresults stayed consistent over five grow-ing cycles. At the end of the study, thescientists tallied up the surprising results.

Daily weight gain increased 6.1 percent,and feed conversion improved 5.1 percent.Animal mortality decreased 47 percent,and cull weight was reduced 80 percent.The farmer sold an average of 5,265 pigsper growing cycle, which resulted in a1,138,247-pound net gain per cycle. Us-ing the second-generation system insteadof the lagoon system, the farmer sold61,400 pounds more hogs—a 5.8 percentincrease—per growing cycle.

“Participating in the program took myaverage farm to the top of the field,” Tyn-dall declares.

The scientists attribute the productiv-ity improvement in part to the improvedair quality and health conditions in thebarns. Since the recycled wastewater wasmostly ammonia free, ambient ammonialevels in the barns dropped an average of75 percent.

“Improvement in animal production isimportant to farmers because that’s theirbottom line,” Vanotti says.

Fetterman, their Terra Blue, Inc., part-ner, sees it from another angle. “If youtreat the pigs well, they will pay youback,” he says.

Sharing the SuccessThe second-generation system was

discussed in a chapter of “ManufacturingClimate Solutions: Carbon-ReducingTechnologies and U.S. Jobs,” publishedin 2008 by Duke University. The reportwas commissioned by the AFL-CIO andthe Environmental Defense Fund andfeatured technologies that could helpreduce greenhouse gas emissions andcreate green jobs in the United States.

The authors concluded that the second-generation system could help swine-producing states protect existing jobsand keep the door open for future jobexpansion.

In 2009, the USDA Natural ResourcesConservation Service’s EnvironmentalQuality Incentives Program began a 5-yearinitiative with additional funding for North

Carolina livestock farmers who participatein the LCP. At the time the program wasestablished, only the second-generationsystem met all the LCP qualificationsfor funding, which will pay for up to 90percent of the costs involved in installingan EST for manure management.

“When one considers the many directand indirect benefits of the cleaner hog-waste technology, farmers and society maynot be able to afford not to convert to thenew technologies,” Fetterman observes.

“We learned our lessons and tried tomake a new system as simple to operateand economical as possible,” Vanotti adds.“Now we need to install these systems ina sufficient number of farms to confirmtheir environmental benefits at a regionalscale and to facilitate the development ofmarkets for co-products from recoveredmanure nutrients.”—By Ann Perry,ARS.

This research is part of Manure andByproduct Utilization (#206), WaterAvailability and Watershed Management(211), and Food Safety (#108), three ARSnational programs described at www.nps.ars.usda.gov.

Matias B. Vanotti and Ariel A. Szogi arewith the USDA-ARS Coastal Plains Soil,Water, and Plant Research Center, 2611W. Lucas St., Florence, SC 29501-1242;phone (843) 669-5203, ext. 108 [Vanotti],(843) 669-5203, ext. 109 [Szogi], [email protected], [email protected]. *

PEGGY GREB (D1779-1)PEGGY GREB (D1778-1)












The coconut tree is a symbol of the Tropics, and as a source offiber, food, fuel, soap, and cooking oil, it is sometimes called“the tree of life.” But one aspect of the tree has remained a mys-tery—its origins. Scientists have debated the tree’s genealogicalroots for decades.

Using genetic markers found in coconuts and other palmtrees from around the world, Alan Meerow, a geneticist with theUSDA-ARS Subtropical Horticulture Research Station in Miami,Florida, has completed a phylogenetic analysis of a large group

of palm species (the Attaleinae subtribe) that provides the mostcomprehensive look yet at the coconut tree’s family history. Theresults suggest that the ancestors of the coconut tree originated inSouthAmerica, that the tree’s closest living relatives are a moderngenus of American palms (the genus Syagrus), and that it di-verged from them about 35 million years ago. The genus Syagrusincludes another popular Florida ornamental, the queen palm.

Meerow and colleagues also found that the modern coconuttree probably evolved about 11 million years ago, perhaps inthe South Pacific. The Fiji Dwarf, a variety of coconut tree nowgrown in the United States, shares its South Pacific ancestry withmany of today’s other coconut varieties, according to Meerow.“The Fiji Dwarf is more distantly related to all these other vari-eties,” he says.

The work, published in PLoS One, is more than an academicexercise. Five of the 80 known varieties of coconut tree are majorornamentals in Florida. Identifying their closest relatives will helpin the search for genes with traits capable of resisting diseases,insect pests, and other threats. An epidemic of lethal yellowingphytoplasma in the early 1980s destroyed an estimated 100,000coconut palms in South Florida. Bud rot, caused by several fun-gal pathogens, threatens coconut production around the world.

“The more we know about it, the easier it will be to addressfuture threats,” Meerow says.

Patterns of differences in DNA can open a window into aplant’s evolutionary past, revealing when it diverged from itsancestors. Meerow and colleagues looked for patterns amonga family of genes developed as markers by ARS researchersstudying cacao (chocolate) plants. Known as “WRKY genes,”they are valuable “clocks” for dating the occurrence of importantevolutionary events.

With these molecular clocks and evidence from fossil palms,Meerow traced the coconut tree’s ancestry back more than 40million years to palms that grew in both Madagascar and easternBrazil. He also found that milestones in the coconut’s early “fam-ily tree” coincide with major geological events in SouthAmerica,making it likely they played a role in how these palms evolved.A group of palm species in southern Brazil, for example, split offfrom a relative in Chile about 14 million years ago, around thetime when geological events gave rise to the Andes Mountains.The extensions of oceans into the western Amazon region thatlasted from 25 to 30 million years turned dry areas into wetlandsand probably altered the evolution of coconut ancestors growingat the time across South America, Meerow says.—By DennisO’Brien, ARS.

This research is part of Plant Genetic Resources, Genomics,and Genetic Improvement, an ARS national program (#301)described at www.nps.ars.usda.gov.

Alan W. Meerow is with the USDA-ARS Subtropical Horticul-ture Research Station, 12501 Old Cutler Rd., Miami, FL 33158;(786) 573-7075, [email protected]. *

The coconut variety Niu Leka, or Fiji Dwarf (see back cover), fromthe South Pacific may represent the earliest lineage in the coconut’sdomestication.

A SYMBOLOF THETROPICS

Unraveling theOrigins of

http://www.ars.usda.gov/is/contacts.htm#Dennis




STRESSSTRESSSTRESSSTRESSIT’S NOT JUST FORYOU AND ME

STEPHEN AUSMUS (K10003-7)


Vitamin C and beta-glucansupplements can help pigletsgain weight after weaning.


Whenever we feel stress—like falling off a ladder—our bodiesreact in predictable ways—increased heart rate, rapid and shal-low breathing, and an adrenaline rush. Animals feel stress too,and it can compromise their health and ability to thrive. That, inturn, can cost producers money.

Researchers in the Livestock Behavior Research Unit in WestLafayette, Indiana, study stress in poultry, swine, and cattle.

In one study, research leader Donald C. Lay, Jr., used animalrestraint and stress-inducing hormone injections of sows asstressors. He found that prenatal stress, the stress imposed on apregnant animal, resulted in widespread effects on the offspring.

“Prenatal stress has been shown to have effects on the behav-ior and physiology of many species, including monkeys, rats,guinea pigs, goats, humans, and swine,” says Lay. “Research inour lab has shown that prenatal stress, from restraint and stresshormone injection of sows, caused offspring to have increasedplasma cortisol levels in response to stress and less ability toheal a wound when subjected to stress.”

Cortisol is a glucocorticoid—a class of steroid hormones thatsuppress the immune system. Cortisol can also raise blood pres-sure and blood sugar levels.

“Prenatal stress has been shown to cause an increase in fetalcortisol, which may in turn impair immune function and increasethe maximum binding capacity of glucocorticoid receptors in thecentral nervous system immediately after birth.”

Pigs in social groups are known to form hierarchies. Sowsat the bottom of the hierarchy may produce litters of prenatallystressed piglets. Lay and his colleagues have shown that the ef-fects associated with prenatal stress in swine, however, are notcaused by cortisol alone. They are continuing research to identifythe other factors involved.

Treating Farm Animal Stress from the Inside OutAnimal well-being can be improved and stress counteracted

in farm animals by enhancing their enteric health and immunitythrough dietary supplements. In studies to reduce the negativehealth effects of a known stressor—such as animal transport andhandling—animal physiologist Susan Eicher has shown that beta-glucan (a yeast cell-wall product) and vitamin C supplements,fed together, can improve piglet health by enhancing the animals’growth and immune function after transport.

In Eicher’s studies, piglets received diets supplemented withbeta-glucan alone, vitamin C alone, or both beta-glucan and vi-tamin C. An unsupplemented diet was fed to piglets as a control.

“Piglets receiving both vitamin C and beta-glucan had a greaterweight gain after weaning,” says Eicher. “We also detectedchanges in the expression of immune-system communicationmolecules called ‘cytokines’ in intestinal and liver tissues.”Other animal species may also benefit from this combinationdiet during stressful times, such as transport.

This ARS nutritional supplemental combination was patentedin 2005 and is licensed. The marketed product is presently usedby calf producers in Idaho, and they report a lower incidence ofrespiratory problems.

Reducing Stress—and Pain—of Birds’ Beak TrimmingBeak trimming is a routine husbandry procedure used in the

commercial poultry industry—particularly in broiler breedersand laying hens—to reduce injuries during confinement.

During conventional beak trimming, one-third to one-half ofthe beak is removed. A hot blade is normally used to cut andcauterize the beaks of chicks. But the process can be painful tothe birds, so alternative methods are needed.

Biologist Heng Wei Cheng has identified a better technique—infrared laser—that can reduce pain and tissue damage.

“Infrared lasers have been widely used for noninvasive surgi-cal procedures in human medicine and their results are reliable,predictable, and reproducible,” says Cheng. “Infrared lasershave recently been designed with the purpose of providing aless painful, more precise beak-trimming method compared withconventional beak trimming.”

Infrared laser was compared to conventional beak trimming,and the results are promising. “Our results indicate that whilethere was no statistical difference in egg production or bird bodyweight between the two beak-trim treatments, those birds treatedwith the infrared method displayed superior feather condition andreduced aggression, even though they had less of the beak re-moved,” says Cheng. “The data show that infrared beak treatmentmay reduce the damage done by feather pecking and provides abetter alternative to conventional beak trimming. Indeed, infraredtrimming may provide a less invasive alternative to conventionalbeak trimming without compromising productivity.”

These research efforts are just some of many projects of theLivestock Behavior Research Unit that are aimed at improvingexisting practices and inventing new practices that enhance ani-mal well-being and increase animal productivity.—By SharonDurham, ARS.

This research is part of Food Animal Production (#101) andAnimal Health (#103), two ARS national programs described atwww.nps.ars.usda.gov.

Donald C. Lay is in the USDA-ARS Livestock Behavior ResearchUnit, 125 S. Russell Street, West Lafayette, IN 47907; (765) 494-4604, [email protected]. *

KEITH WELLER (K7974-18)

http://www.ars.usda.gov/is/contacts.htm#Sharon




At Young’s Plant Farm in Auburn, Ala-bama, rows of southern pine trees (Pinustaeda) stretch as far as the eye can see.But these trees won’t be used to deco-rate landscapes and parks or to provideshade on a hot day. Instead, these pinetrees—commonly known as “loblollypine”—will be used to grow the vibrant,healthy potted plants we see in nurseriesand garden centers.

Nursery plants are grown in containersfilled with a soil-less potting media, for-mally called “substrate,” which typicallyconsists of Canadian peat moss, perlite(heat-expanded volcanic rock), vermicu-lite (heat-expanded silicate mineral), andpine bark. But the process of harvesting,preparing, and shipping peat moss, perlite,and vermiculite requires tremendous en-ergy inputs. Also, the availability of pinebark has been tenuous because it dependson the stability of various other industriesfrom which pine bark is derived.

Seeing this predicament, horticulturistGlenn Fain, formerly with the ARS ThadCochran Southern Horticultural Laborato-ry in Poplarville, Mississippi, and CharlesGilliam, a professor atAuburn University,began looking for an alternative materialto use as a substrate or substrate com-ponent. Fain continues to collaboratewith Jim Spiers, research leader of thePoplarville laboratory; Anthony Witcher,a doctoral student and horticulturist atPoplarville; and Greg Young, owner ofYoung’s Plant Farm. In 2005 and 2006,ARS, Auburn University, and Young’sPlant Farm entered into specific coopera-tive agreements to develop a new substratethey call “WholeTree.”

Locally Produced, Completely Self-Sustainable

As its name suggests, WholeTree ismade from all parts of the loblolly pine—bark, needles, wood, and cones. Theword “loblolly” means “low, wet place,”but these trees aren’t limited to thatenvironment. Loblolly pines grow well inacidic clay soil, which is commonly foundin the South, and can be found in large

Fresh WholeTree chips being processed into a substrate component at Young’s Plant Farm.

A worker at Young’s Plant Farm transplants seedlings into containers filled with an experimentalsubstrate containing WholeTree.

A More Sustainable, E

GLENN FAIN (D1872-1)

GLENN FAIN (D1873-1)




groups in rural areas. But trees used tomake WholeTree aren’t taken from naturalareas; they’re farmed at tree plantationsacross the southeastern United States.

The pine trees used are those that areharvested from pine plantations at thethinning stage. “Thinning” is when sometrees are removed to achieve a densitythe site can support. The trees are thenchipped and further processed to achievethe desired physical properties needed fora substrate component. Similar productshave been available in Europe for severalyears, but WholeTree could be one of thefirst available products for the UnitedStates made from locally grown materials.

“We’ve taken a locally available prod-uct that’s native to this region and that’salready being farmed, and we’ve used itto make a more environmentally friendlyproduct,” says Fain, now an assistantprofessor atAuburn University. “It’s com-

pletely self-sustainable and would costless than other substrates on the market.”

Field and laboratory studies have dem-onstrated the successful use of WholeTree,

even at 100 percent for some nurseryplants. In one study, Fain and colleaguescompared chrysanthemums grownin WholeTree with those grown in aWholeTree-and-peat moss mix and a peatmoss-and-perlite mix. The scientists col-lected data on plant growth, flower budnumber, leaf chlorophyll content, rootrating, shoot dry weight, and nutrient con-tent of plant tissue. In the end, they foundminimal differences between the plants,all of which were considered marketableat the conclusion of the study. Otherstudies have produced similar results withonly minor changes in cultural practices.

Results from the studies have been sopromising that in 2008, Young’s PlantFarm, a supplier to retail outlets such asLowe’s and Wal-Mart, made a significantinvestment in order to adopt this technol-ogy and further the research on a largerscale. They are now producing their ownsubstrate component, farming and har-vesting pine trees produced at one oftheir farms to make WholeTree. In fact,Wal-Mart recently recognized Young’sPlant Farm for their efforts with a suppliersustainability award for using the product.

“Other plant suppliers can adopt thistechnology, although some cultural prac-tices will have to be altered,” says Fain.“WholeTree has the potential to be aneconomically sustainable substrate com-ponent that could be available in closeproximity to major horticultural produc-tion areas throughout the Southeast.”

FurtherTesting and FutureApplicationsWitcher, Fain, Spiers, and Eugene

Blythe, an assistant research professorat Mississippi State University’s SouthMississippi Branch Experiment Stationin Poplarville, are currently conductingfurther studies evaluating WholeTree’suse in cutting and seedling propagationof herbaceous perennial and woody orna-mental crops. So far, they have conductedtests on plants popular to the ornamentaland landscaping industries, such as thegarden mum, perennial salvia, climbingrose, and Leyland cypress.

“We’ve had promising results, butwe need to further examine the physicalproperties of WholeTree,” says Witcher.“We want to create an optimal mix of airspace and water-holding capacity in thesubstrate to enhance root developmentin these plants. We also want to create aparticle size that works well for a widerange of crops.”

Researchers are planning to conducttrials using WholeTree as a landscapesoil amendment. According to Fain, it istypical practice to add an organic amend-ment to the soil, especially in heavy claysoils. In the southeast, aged pine bark andpeat moss are standard soil amendments.WholeTree will be compared with thesestandards to determine its potential use inthe landscape industry.

Scientists are also planning to conductplant-growth-response trials at otherproducer locations in the southeast. And

they are looking into the possibility ofusing other species of trees growing insouthern forests as standalone substratesor substrate components.

If all goes well, you may soon see plantsgrown in WholeTree in a nursery nearyou.—By Stephanie Yao, ARS.

This research is part of Crop Produc-tion, an ARS national program (#305)described at www.nps.ars.usda.gov.

To reach scientists mentioned in thisarticle, contact StephanieYao, USDA-ARSInformation Staff, 5601 Sunnyside Ave.,Beltsville, MD 20705-5129; (301) 504-1619, [email protected]. *

Glenn Fain evaluates garden chrysanthemumsgrown in WholeTree at the ARS Thad CochranSouthern Horticultural Laboratory in Poplarville,Mississippi.

e, Environmentally Friendly Substrate

“We’ve taken a locallyavailable product that’snative to this region and

that’s already being farmed,and we’ve used it to makea more environmentally

friendly product.”—Glenn Fain

WAYNE J. MCLAURIN (D1874-1)

http://www.ars.usda.gov/is/contacts.htm#Stephanie



Wind turbines for electricity production.


Western juniper trees have thrived inOregon’s high desert for about 6,000years, but in the past century, the aggres-sive conifer has begun to dominate someof the region’s sagebrush grasslands. InBurns, Oregon, Agricultural ResearchService rangeland scientists Jon Batesand Tony Svejcar are finding waysto manage this arboreal invasion andprompt the recovery of perennial grassesand forbs.

Although rangeland managers usecontrolled burns to keep ahead of thejuniper, they also just cut down theproblem trees and leave them wherethey fall. This protects the soil, but thedead trees pose an increased fire risk—and may also create conditions thatencourage establishment of cheatgrass,an invasive annual that fuels fiercewildfires.

Bates and Svejcar conducted a studyat a site dominated by a 90-year-old

western juniper woodland—a site oncevegetated with basin big sagebrushand associated perennial grasses andforbs—to determine whether burningthe cut junipers would help reestablishthe perennials. Burning was done duringtwo consecutive winters after cutting. Acontrol group of felled trees at the sitewas left unburned.

Results indicate that burning the treeswhen soils were frozen prompted amore successful recovery of perennialsand helped keep cheatgrass establish-ment at bay. Ten years after burning,total perennial grass cover was 1.5 to2 times greater in the areas where treeshad been burned than in the areas wherethey were not burned. Perennial grassdensity was 60 percent greater in theburned areas than in the unburned areas,and cheatgrass was twice as dense in thecontrol area as in the two burned areas.

The scientists concluded that native

Brian Vick found that, in parts of Texasand California, an almost perfect matchbetween wind-power production andpeak energy demands can be obtained bycombining wind power with solar power,and by proper storage of excess energywhen power supply exceeds demand.

Vick is an agricultural engineer at theAgricultural Research Service’s Renew-able Energy and Manure ManagementResearch Unit in Bushland, Texas.

Vick found that in both the Texas Pan-handle and California, there is almostan exact mismatch between wind-powerproduction and peak energy demandsover a 24-hour period. In these locations,at the tops of modern wind turbines,winds are lowest at midday, when powerdemands are greatest. In Texas, there isa seasonal mismatch as well: The windsare weakest in the summer, when powerdemands peak. But adding solar powerhelps because the sun’s rays are most in-tense at midday and in summer months.

When wind or sun power generatedexceeds demand, it’s important to cap-ture the energy and store it. The most ef-ficient storage system is one being usedin solar thermal power plants, wherethe sun’s energy is used to heat water orother fluids. The fluids are kept hot longafter the sun goes down and can be usedlater to produce steam to generate elec-tricity. The excess electricity generated

by wind in the late night and early morn-ing hours could be pumped into the gridand stored to supply power when windand solar power are insufficient.

Vick and colleagues at Bushland de-sign and test wind/solar/biodiesel hybridsystems running on an experimentalelectric grid. They also operate modernturbines for wind-farm research for theU.S. Department of Energy.

Vick expects that a better blending ofsolar and wind power will increase theuse of renewable energy for California,Texas, and the rest of the nation. Texasis the top state for wind-generated elec-tricity production, with Iowa second andCalifornia third. California is the leaderin solar-generated electricity produc-tion.—By Don Comis, ARS.

Brian D. Vick is in the USDA-ARSRenewable Energy and Manure Manage-ment Research Unit, 2300 ExperimentStation Rd., Bushland, TX 79012-0010;(806) 356-5752, [email protected].

perennial communitiescould recover fromjuniper invasions mosteffectively when thefelled junipers wereburned rather thancut and left. Burningin winter, when soilswere wet or frozen,helped limit damage toexisting perennials at thesite and gave them a head start in theirgrowth the following spring, when theyneeded an edge against invasive annu-als.—By Ann Perry, ARS.

Jon Bates and Tony Svejcar are withthe USDA-ARS Range and MeadowForage Management Research Unit,Eastern Oregon Agricultural ResearchCenter, 67826-A, Hwy. 205, Burns, OR67826; (541) 573-8932 [Bates], (541)573-8901 [Svejcar], [email protected], [email protected].

Power Needs and Wind Power as Different as Day and Night

Torching Invasive Trees Revives Rangeland Perennials

SCOTT BAUER (K5474-12)







Sustainable Corn Production SupportsAdvanced Biofuel Feedstocks

Researchers have found a cost-effective, energy-efficient, andenvironmentally sustainable method to use corn stover for gener-ating an energy-rich oil called “bio-oil” and for making biocharto enrich soils and sequester carbon. The team used fast pyrolysisto transform corn stover and cobs into bio-oil and biochar. Theyfound that the bio-oil captured 70 percent of thetotal energy input, and the energy density of thebio-oil was 5 to 16 times that of the feedstock.This suggests it could be more cost effective toproduce bio-oil through a distributed networkof small pyrolyzers and then transport thecrude bio-oil to central refining plants to make“green gasoline” or “green diesel,” rather thantransporting bulky stover to a large centralizedcellulosic ethanol plant. About 18 percent ofthe feedstock was also converted into biochar,which contains most of the mineral nutrients inthe corn residues. Amending soils with this biochar would returnthose nutrients to the soil, reduce leaching of other nutrients,help build soil organic matter, and sequester carbon. CharlesMullen, USDA-ARS Crop Conversion Science and EngineeringResearch Unit, Wyndmoor, Pennsylvania; (215) 836-6916,[email protected].

Tough New Spuds Take on Double Trouble Powdery scab and black dot can cause yield losses of up to

25 percent in potato crops and prevent tubers from reachingthe sizes needed by the French-fry and fast-food industries.Now, five new potato breeding lines could lead to develop-ment of cultivars that are resistant to the fungal pathogensthat cause both diseases. After screening a collection of wildand cultivated potatoes for sources of natural resistance topowdery scab and black dot, researchersdeveloped the five advanced potatobreeding lines from a wild speciesfrom Mexico, Solanum hougasii,and a recent commercial release,Summit Russet. In 3 years of fieldtrials, the potato breeding lines con-sistently showed fewer disease symptoms—root galling forpowdery scab and sclerotia-infected stems for black dot—thanother lines and varieties tested. These new lines will be madeavailable as seed for potato breeding programs working to de-velop the first commercial varieties with dual resistance to thefungal diseases. Chuck Brown, USDA-ARS Vegetable and For-age Crops Research Laboratory, Prosser, Washington; (509)786-9252, [email protected].

Fungi May Hold Key to Reducing Grapefruit JuiceInteractions with Medications

Grapefruit juice can interfere with the effectiveness of somemedications because it contains furanocomarins, which are oneof many types of phytochemicals commonly found in plants.Furanocomarins inhibit the enzymatic activities responsible formetabolizing certain medications and facilitating their releaseinto the bloodstream. Researchers have found that the fungusAspergillus niger either binds with grapefruit furanocomarinsor enzymatically breaks them down. Studiesare continuing to identify the enzymesin A. niger that prompt the breakdownof furanocomarins to see if these en-zymes could be used to eliminate thecompounds from grapefruit juice.

In another study, when edible mush-rooms that are related to A. niger—includ-ing morels and oyster and button mushrooms—were dried,pulverized, and added to grapefruit juice, they also removedfuranocomarins. These findings provide additional evidencethat proteins from A. niger and other fungi might someday leadto new methods for removing furanocomarins from grapefruitjuice. Jan Narciso, USDA-ARS Citrus and Subtropical ProductsLaboratory, Winter Haven, Florida; (863) 293-4133, ext. 119,[email protected].


Plant Hormone Increases Cotton Yieldsin Drought Conditions

A naturally occurring class of plant hormones called “cy-tokinins” has been found to boost yields from cotton cropsthat receive little or no irrigation during drought conditions.Young cotton seedlings have difficultyreaching available soil water becausethey have small root systems. By trick-ing water-stress defenses in the youngplants, cytokinins prompt the plant toquickly build a bigger root system thatcan access deep soil moisture. They alsostimulate the growth of a protective wax onthe surface of the plant that helps reduce water loss. Testresults indicated that one application of cytokinins produced a5- to 10-percent increase in yields under water-reduced condi-tions. In addition, the hormones didn’t help or hinder yieldsunder fully irrigated or rainy conditions, which makes themsafe to use in all weather environments. There is also no extrawork involved for the grower, because cytokinins can be ap-plied when conducting normal weed-management practicesearly in the season. John Burke, USDA-ARS Cropping SystemsResearch Laboratory, Lubbock, Texas; (806) 749-5560, ext.5216, [email protected].





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