Impacts of Treated and Slow Release Fertilizer Applications On Nitrous Oxide Emissions.

The use of slow release or inhibitor-treated nitrogen fertilizers can potentially reduce nitrous oxide (N₂O) emissions by improving the coordination of nitrogen availability and plant uptake, thus reducing the accumulation of nitrates that can be denitrified.  A study was initiated in 2009 to compare N₂O emissions when corn was fertilized with urea, SuperU (urea formulated with urease and nitrification inhibitors), ESN (polymer coated urea), urea ammonium nitrate (UAN), UAN with AgrotainPlus (urease and nitrification inhibitors), and PiNT (amine-N). The treatments were replicated on a well-drained and a poorly-drained site.  In 2009, within treatment variability was very high and no statistically significant differences were seen among fertilizer treatments for both the poorly- and well-drained sites.   However, overall nitrous oxide emissions were nearly double on the poorly-drained site.  The 2009 findings suggest that spatial variation in soil moisture and aeration may have a larger impact on N₂O emission than the form and treatment of the fertilizer.  The study is being repeated in 2010 and those findings will be presented.