Year 12 | 27 January 2020 | email@example.com
Agricultural Research Service (ARS) scientists are front and center in finding out how farming affects emissions of the green house nitrous oxide (N2O).
Experts already know that N2O emissions rise as applications of nitrogen-based fertilizers increase. Microbiologist Tim Parkin, who works at 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 N2O emissions.
The researchers assessed the variation in the emissions of N2O, carbon dioxide and methane from two different soil types—a sandy loam mix and a clay soil. 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.
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. This is because in a reduced tillage system, the microorganisms that support N2O emissions are concentrated in the topmost soil layer.
by S. C.
11 december 2009, Technical Area > Science News