From: ARS News Service [mailto:[log in to unmask]]
Sent: Friday, June 12, 2009 8:26 AM
Subject: Reaping More Rewards from Crop Residues
Reaping More Rewards from Crop Residues
ARS News Service
Agricultural Research Service, USDA
Ann Perry, (301) 504-1628, [log in to unmask]
June 12, 2009
--View this report online, plus photos and related stories, at
Wheat and barley producers in Washington State's Palouse region can
refine crop residue management to build soil organic matter, curb soil
erosion, retain soil moisture and maximize crop yields, thanks to
support from the Agricultural Research Service (ARS).
ARS soil scientist Ann Kennedy and Tami Stubbs of Washington State
University (WSU) worked with other WSU and ARS colleagues to conduct a
two-year study of post-harvest crop residues to identify links between
decomposition processes and fiber and nutrient characteristics of the
straw. Kennedy works at the ARS Land Management and Water Conservation
Research Unit in Pullman, Wash.
The researchers looked at residues from 17 cultivars of winter wheat, 16
cultivars of spring wheat and nine cultivars of spring barley grown at
four locations in southeastern Washington. The team measured the content
of hemicellulose, cellulose and lignin in each type of residue. They
also measured residue levels of carbon and nitrogen and the ratio of the
amount of carbon to nitrogen (C/N).
The team found that the straw from the different cultivars had notable
differences in fiber composition and C/N ratios. Fiber composition, C/N
ratios and carbon levels also varied significantly by location, probably
because of different soil and growing conditions. Residue samples from
Pullman, where annual precipitation averages 20 inches, had higher
lignin and C/N and lower nitrogen than residues from the driest site,
where annual precipitation averages 11 inches.
These results and other tests on the straw residues indicated that 14
percent of the cultivars had characteristics for slow residue
decomposition and 14 percent had characteristics indicating a potential
for rapid decomposition. Crop residues decompose into soil organic
matter, which provides nutrients to crops, limits erosion and helps
retain soil moisture. Rapidly decomposing cultivars are less likely to
impede no-till seeding in higher rainfall areas where more straw is
The identification of differences in these crop characteristics could
help growers select cultivars that produce residues best adapted to
reduced-tillage cultivation. These residues may also benefit subsequent
crop establishment, maximize soil organic matter to improve yield and
increase carbon stored in the soil.
ARS is the principal intramural scientific research agency of the U.S.
Department of Agriculture.
This is one of the news reports that ARS Information distributes to
subscribers on weekdays. Send feedback and questions to the ARS News
Service at [log in to unmask]
ARS News Service, Information Staff, Agricultural Research Service
5601 Sunnyside Ave., Room 1-2251, Beltsville MD 20705-5128
[log in to unmask] | www.ars.usda.gov/news
Phone (301) 504-1636 | fax (301) 504-1486
Enviro-News is a service of the Water Quality
Information Center at the National Agricultural
Library. The center's Web site is at
The Enviro-News list facilitates information exchange.
Inclusion of an item in Enviro-News does not imply
United States Department of Agriculture(USDA) agreement,
nor does USDA attest to the accuracy or completeness of
the item. See
You can contact the list owner at
[log in to unmask]