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United States Department of Agriculture

Agricultural Research Service

Research Project: NITROGEN FERTILIZER USE EFFICIENCY AND ENVIRONMENTAL IMPACT ASSESSMENT

Location: Pasture Systems & Watershed Management Research

2012 Annual Report


1a.Objectives (from AD-416):
Measure the crop production and environmental impacts of using new fertilizer technology.


1b.Approach (from AD-416):
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.


3.Progress Report:

In a third trial on turfgrass conducted in 2011, PiNT-K compared favorably to inorganic fertilizer analogs, but showed no significant benefits in comparison with urea-based fertilizers. Data from nitrogen fertilizer trials on corn during the 2011 growing season were analyzed. Results were highly variable due to drought conditions. There were no significant differences in corn grain or silage yields among plots fertilized with PiNT-Ca, PiNT-K, or urea ammonium nitrate (UAN). An incubation experiment comparing the persistence of amines in a high pH, low cation exchange capacity soil from Texas (Kermit series) showed no significant differences among soil treated with PiNT-Ca, PiNT-K, or UAN. Amines were completely converted to ammonium and nitrate within 28 days. Results show that amines in PiNT-Ca and PiNT-K are not stable in this soil under moist conditions.


Last Modified: 10/1/2014
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