SOIL CARBON AND CLIMATE CHANGE NEWS
From Kansas State University's:
Consortium for Agricultural Soils Mitigation of Greenhouse Gases (CASMGS)
Charles W. Rice, K-State Department of Agronomy, National CASMGS Director
(785) 532-7217 firstname.lastname@example.org
Scott Staggenborg, K-State Department of Agronomy (785) 532-7214 email@example.com
Steve Watson, CASMGS Communications (785) 532-7105 firstname.lastname@example.org
December 23, 2009
Effect of different nitrogen fertilizer sources
and soils on nitrous oxide emissions
Soil microbiologist Tim
Parkin, with the ARS National Laboratory for Agriculture and the Environment in
Ames, Iowa, is part of a team that is studying how different soils and different
fertilizers affect nitrous oxide (N2O) emissions.
The researchers assessed the variation in the emissions of N2O, carbon dioxide, and methane from two different soil types -- sandy loam and clay. The two fertilizers used in the study were urea-ammonium nitrate (UAN) and a liquid swine manure slurry.
They found that overall, N2O emission levels were highest from soils amended with swine manure slurry. High levels of N2O emissions were measured from sandy loam soils amended either with UAN or slurry. But on the clay soils, only those amended with slurry -- and not with UAN -- had elevated N2O emissions.
Soil scientist Rod Venterea, who works at the ARS Soil and Water Management Research Unit in St. Paul, Minn., is also studying N2O emission dynamics. He found that the amount of N2O emitted from fields fertilized with anhydrous ammonia was on average twice as high as emissions from fields fertilized with urea.
His findings also suggest that farmers using reduced tillage can minimize N2O emissions by placing fertilizers below the upper 2 to 3 inches of soil.
Results from Parkin's research were published in the Journal of Environmental Quality in 2008. Venterea's work was published in Global Change Biology in 2007 and the Journal of Environmental Quality in 2005 and 2008.
-- USDA-ARS News Service, December 9, 2009
For more information, see: http://www.ars.usda.gov/is/AR/archive/nov09/nitrous1109.htm