Start Date: Dec 01, 2009
End Date: May 14, 2012
This series of experiments will include a controlled release polymer-coated urea (ESN), stabilized urea sources of SuperU and urea ammonium nitrate (UAN) treated with AgrotainPlus, a cation-stabilized amine (PiNT), conventional sources of UAN and urea, and an unfertilized check. An N source study will be conducted at the Russell E. Larson Agricultural Research Center at Rock Springs, PA to determine gaseous losses. Nitrous oxide gas emissions will be measured throughout the growing season using vented chambers with gas analysis by gas chromatography. Crop yield, soil N content, temperature, soil water, and other data required to determine N use efficiency and interpret the emission results will be collected. In complementary laboratory experiments, ammonia and nitrous oxide emissions will be measured on surface soil samples collected from the field site and incubated in jars under controlled soil moisture conditions. Nitrogen losses in runoff will be measured on runoff boxes packed with soil collected from the University of Maryland Eastern Shore (UMES) experiment station, amended with the seven N fertilizer treatments described above, and subjected to simulated rainfall following the rainfall simulation protocol for indoor soil boxes as developed and described by the National P Project. N losses in the form of ammonium, nitrate and urea will be determined by flow injection analyses. Nitrogen leaching losses from the fertilizer treatments will be measured on soil columns using intact soil cores collected from the University of Maryland Eastern Shore (UMES) experiment station and at Rock Springs, PA on turfgrass plots established on constructed greens equipped with lysimeters.