Increased N2O emissions during soil drying after waterlogging and spring thaw in a record wet year
Increased N2O emissions during soil drying after waterlogging and spring thaw in a record wet year
复制标题
在创纪录的多雨年份，涝灾和春季解冻后土壤干燥期间 N2O 排放量增加
DOI：
10.1016/j.soilbio.2016.07.016
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发表时间：
2016-10-01
影响因子：
9.7
通讯作者：
Fan, Jianling
中科院分区：
文献类型：
--
作者：
Chen, Zengming;Ding, Weixin;Fan, Jianling
Global climate change is expected to increase the frequency and intensity of extreme precipitation events, which can dramatically alter soil nitrous oxide (N2O) emissions. However, our ability to predict this effect is limited due to the lack of studies under real-world conditions. We conducted a field experiment in a maize-cultivated black soil in northeast China with six treatments: control without nitrogen (N) application (CK) and N-fertilized treatments with the ratio of urea N to manure N at 100:0 (NPK), 75:25 (OM1), 50:50 (OM2), 25:75 (OM3) and 0:100 (OM4). The experimental year was the wettest on record with an extreme rainfall event of 178 mm occurring in summer 2013. Annual N2O emissions from CK and NPK were increased by 168% and 171%, respectively, relative to normal wet years. Extreme rainfall saturated soils, resulted in low N2O fluxes (3 mg N kg(-1) and water-filled pore space was 67-76%. Distinctly higher N2O fluxes were also identified during the spring thaw period, accumulating to 20.1-49.4% of the non growing season emissions. Emissions upon thawing were likely related to denitrification induced by high moisture conditions as a result of lag effect of the extreme rainfall. Annual N2O emissions progressively reduced as the ratio, of urea N:manure N shifted towards manure, which was also the case during soil drying after waterlogging. Total N2O emissions were reduced by 25.6% for OM4 than NPK. Overall, our results suggest that soil N2O emissions were increased in the record wet year but a shift from urea towards manure with more N applied as starter N can minimize the N2O losses. (C) 2016 Elsevier Ltd. All rights reserved.
