气候变化领域集成服务门户(CCPortal): Nitrous oxide emissions from agricultural soils challenge climate sustainability in the US Corn Belt

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DOI	10.1073/pnas.2112108118
	Nitrous oxide emissions from agricultural soils challenge climate sustainability in the US Corn Belt
	Lawrence N.C.; Tenesaca C.G.; VanLoocke A.; Hall S.J.
发表日期	2021
ISSN	0027-8424
卷号	118 期号:46
英文摘要	Agricultural landscapes are the largest source of anthropogenic nitrous oxide (N2O) emissions, but their specific sources and magnitudes remain contested. In the US Corn Belt, a globally important N2O source, in-field soil emissions were reportedly too small to account for N2O measured in the regional atmosphere, and disproportionately high N2O emissions from intermittent streams have been invoked to explain the discrepancy. We collected 3 y of highfrequency (4-h) measurements across a topographic gradient, including a very poorly drained (intermittently flooded) depression and adjacent upland soils. Mean annual N2O emissions from this corn-soybean rotation (7.8 kg of N2O-N ha21_y21) were similar to a previous regional top-down estimate, regardless of landscape position. Synthesizing other Corn Belt studies, we found mean emissions of 5.6 kg of N2O-N ha21_y21 from soils with similar drainage to our transect (moderately well-drained to very poorly drained), which collectively comprise 60% of corn-soybeancultivated soils. In contrast, strictly well-drained soils averaged only 2.3 kg of N2O-N ha21_y21. Our results imply that in-field N2O emissions from soils with moderately to severely impaired drainage are similar to regional mean values and that N2O emissions from well-drained soils are not representative of the broader Corn Belt. On the basis of carbon dioxide equivalents, the warming effect of direct N2O emissions from our transect was twofold greater than optimistic soil carbon gains achievable from agricultural practice changes. Despite the recent focus on soil carbon sequestration, addressing N2O emissions from wet Corn Belt soils may have greater leverage in achieving climate sustainability. © 2021 National Academy of Sciences. All rights reserved.
英文关键词	Agriculture; Climate change; Greenhouse gas emissions; Nitrous oxide; Soil drainage
语种	英语
来源期刊	Proceedings of the National Academy of Sciences of the United States of America
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/238310
作者单位	Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA 50011, United States; Department of Agronomy, Iowa State University, Ames, IA 50011, United States
推荐引用方式 GB/T 7714	Lawrence N.C.,Tenesaca C.G.,VanLoocke A.,et al. Nitrous oxide emissions from agricultural soils challenge climate sustainability in the US Corn Belt[J],2021,118(46).
APA	Lawrence N.C.,Tenesaca C.G.,VanLoocke A.,&Hall S.J..(2021).Nitrous oxide emissions from agricultural soils challenge climate sustainability in the US Corn Belt.Proceedings of the National Academy of Sciences of the United States of America,118(46).
MLA	Lawrence N.C.,et al."Nitrous oxide emissions from agricultural soils challenge climate sustainability in the US Corn Belt".Proceedings of the National Academy of Sciences of the United States of America 118.46(2021).