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Nitrogen Source and Placement Effects on Soil Nitrous Oxide Emissions from No‐Till Corn
Author(s) -
Halvorson Ardell D.,
Del Grosso Stephen J.
Publication year - 2012
Publication title -
journal of environmental quality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 171
eISSN - 1537-2537
pISSN - 0047-2425
DOI - 10.2134/jeq2012.0129
Subject(s) - loam , nitrous oxide , agronomy , nitrification , urea , fertilizer , growing season , environmental science , ammonium nitrate , nitrogen , coated urea , no till farming , chemistry , nitrate , soil water , soil fertility , soil science , biology , organic chemistry
A nitrogen (N) source comparison study was conducted to further evaluate the effects of inorganic N source and placement on growing‐season and non‐crop period soil nitrous oxide (N 2 O). Commercially available controlled‐release N fertilizers were evaluated for their potential to reduce N 2 O emissions from a clay loam soil compared with conventionally used granular urea and urea‐ammonium nitrate (UAN) fertilizers in an irrigated no‐till (NT) corn ( Zea mays L.) production system. Controlled‐release N fertilizers evaluated were: a polymer‐coated urea (ESN), stabilized urea (SuperU), and UAN+AgrotainPlus (SuperU and AgrotainPlus contain nitrification and urease inhibitors). Each N source was surface band applied (202 kg N ha −1 ) near the corn row at emergence and watered into the soil the next day. Subsurface banded ESN (ESNssb) and check (no N applied) treatments were included. Nitrous oxide fluxes were measured during two growing seasons and after harvest using static, vented chambers. All N sources had significantly lower growing‐season N 2 O emissions than granular urea (0.7% of applied N), with UAN+AgrotainPlus (0.2% of applied N) and ESN (0.3% of applied N) having lower emissions than UAN (0.4% of applied N). Similar trends were observed when expressing N 2 O emissions on a grain yield and N uptake basis. Corn grain yields were not different among N sources but were greater than the check. Selection of N fertilizer source can be a mitigation practice for reducing N 2 O emissions in NT, irrigated corn in semiarid areas. In our study, UAN+AgrotainPlus consistently had the lowest level of N 2 O emissions with no yield loss.