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Net Global Warming Potential and Greenhouse Gas Intensity Influenced by Irrigation, Tillage, Crop Rotation, and Nitrogen Fertilization
Author(s) -
Sainju Upendra M.,
Stevens William B.,
CaesarTonThat Thecan,
Liebig Mark A.,
Wang Jun
Publication year - 2014
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/jeq2013.10.0405
Subject(s) - agronomy , environmental science , irrigation , fertilizer , loam , tillage , greenhouse gas , hordeum vulgare , crop residue , crop rotation , soil carbon , crop , soil water , agriculture , poaceae , biology , soil science , ecology
Little information exists about how global warming potential (GWP) is affected by management practices in agroecosystems. We evaluated the effects of irrigation, tillage, crop rotation, and N fertilization on net GWP and greenhouse gas intensity (GHGI or GWP per unit crop yield) calculated by soil respiration (GWP R and GHGI R ) and organic C (SOC) (GWP C and GHGI C ) methods after accounting for CO 2 emissions from all sources (irrigation, farm operations, N fertilization, and greenhouse gas [GHG] fluxes) and sinks (crop residue and SOC) in a Lihen sandy loam from 2008 to 2011 in western North Dakota. Treatments were two irrigation practices (irrigated vs. nonirrigated) and five cropping systems (conventional‐till malt barley [ Hordeum vulgaris L.] with N fertilizer [CTBN], conventional‐till malt barley with no N fertilizer [CTBO], no‐till malt barley–pea [ Pisum sativum L.] with N fertilizer [NTB‐P], no‐till malt barley with N fertilizer, and no‐till malt barley with no N fertilizer [NTBO]). While CO 2 equivalents were greater with irrigation, tillage, and N fertilization than without, N 2 O and CH 4 fluxes were 2 to 218 kg CO 2 eq. ha −1 greater in nonirrigated NTBN and irrigated CTBN than in other treatments. Previous year's crop residue and C sequestration rate were 202 to 9316 kg CO 2 eq. ha −1 greater in irrigated NTB‐P than in other treatments. Compared with other treatments, GWP R and GWP C were 160 to 9052 kg CO 2 eq. ha −1 lower in irrigated and nonirrigated NTB‐P. Similarly, GHGI R and GHGI C were lower in nonirrigated NTB‐P than in other treatments. Regardless of irrigation practices, NTB‐P may lower net GHG emissions more than other treatments in the northern Great Plains.