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Urea Nitrapyrin Placement Effects on Soil Nitrous Oxide Emissions in Claypan Soil
Author(s) -
Steusloff Tyler W.,
Nelson Kelly A.,
Motavalli Peter P.,
Singh Gurbir
Publication year - 2019
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/jeq2019.01.0031
Subject(s) - nitrous oxide , urea , fertilizer , soil water , zoology , growing season , soil horizon , environmental science , human fertilization , agronomy , chemistry , soil science , biology , organic chemistry
Corn ( Zea mays L.) production in poorly drained claypan soils in the US Midwest is a challenge due to low soil permeability, which may result in wetter soil conditions and relatively large amounts of soil N 2 O emissions early in the growing season. The objectives of this study were to determine the effects of urea fertilizer placement with and without nitrapyrin (NI) on daily and cumulative soil N 2 O emissions, and yield‐scaled N 2 O emissions in 2016 and 2017. Treatments included urea deep banded to a 20‐cm depth (DB), urea deep banded to 20 cm plus NI (DB+NI), urea incorporated after a surface broadcast application to ∼8‐cm depth (IA), urea broadcast on the soil surface (SA), and a nonfertilized control (NTC). Fertilizer was applied at 202 kg N ha −1 . Surface soil N 2 O efflux rates were generally lower (<50 g N 2 O‐N ha −1 d −1 ) during the first 3 wk after N fertilization and latter parts of the growing seasons. When averaged across the 2016 and 2017 growing seasons, all fertilized treatments had significantly greater (2.33–5.60 kg N 2 O‐N ha −1 , P < 0.05) cumulative soil N 2 O emissions than NTC. The DB+NI treatment had 54 and 55% lower cumulative soil N 2 O emissions than IA and SA, respectively. In 2017, DB+NI had similar soil yield‐scaled N 2 O emissions to NTC. Percentage grain yield increase over NTC was highest for DB and DB+NI. Grain yield in 2016 was 14 to 18% higher for DB and DB+NI than SA. Results suggest that DB+NI is an effective management strategy for reducing cumulative soil N 2 O emissions and increasing grain yields over the growing season. Core Ideas Deep‐banded urea + nitrapyrin had 55% less soil N 2 O emissions than surface‐applied. Nonfertilized control and deep‐banded urea + nitrapyrin had similar N 2 O emissions. Deep‐banded urea + nitrapyrin had a 1.6% lower emission factor than surface‐applied urea. Deep‐banded urea had a 1.0% lower emission factor than surface‐applied urea.