Food benefit and climate warming potential of nitrogen fertilizer uses in China
Food benefit and climate warming potential of nitrogen fertilizer uses in China
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DOI：
10.1088/1748-9326/7/4/044020
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发表时间：
2012-10
影响因子：
6.7
通讯作者：
H. Tian;Chaoqun Lu;J. Melillo;W. Ren;Yao Huang;Xiaofeng Xu;Mingliang Liu;Chi Zhang;Guangsheng Chen;S. Pan;Jiyuan Liu;J. Reilly
中科院分区：
文献类型：
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作者：
H. Tian;Chaoqun Lu;J. Melillo;W. Ren;Yao Huang;Xiaofeng Xu;Mingliang Liu;Chi Zhang;Guangsheng Chen;S. Pan;Jiyuan Liu;J. Reilly
中国是世界上最大的氮肥消费国，长期以来一直使用化学氮肥来帮助满足不断增长的粮食需求。氮肥使用对粮食安全和气候变化的影响越来越受到关注，但缺乏量化。本文利用碳氮耦合生态系统模型，对1949 - 2008年60年间中国农业增氮的粮食效益和气候后果进行了定量分析。结果表明，施氮后作物产量和土壤固碳量均达到峰值，但随着施氮量的增加，氧化亚氮（N2 O）排放量持续上升。自21世纪初以来，过量使用氮肥通过N2 O排放对全球气候变暖的刺激估计超过了其增加CO2吸收的气候效益。氮肥施用的净增暖效应主要集中在华北平原和长江中下游地区，N2 O排放完全抵消甚至超过CO2汇2倍以上。如果我们减少目前的氮肥水平的60%，在“过度施肥”的地区，N2 O排放量将大大减少，而不会显着影响作物产量和土壤固碳。
Chemical nitrogen (N) fertilizer has long been used to help meet the increasing food demands in China, the top N fertilizer consumer in the world. Growing concerns have been raised on the impacts of N fertilizer uses on food security and climate change, which is lack of quantification. Here we use a carbon–nitrogen (C–N) coupled ecosystem model, to quantify the food benefit and climate consequence of agronomic N addition in China over the six decades from 1949 to 2008. Results show that N fertilizer-induced crop yield and soil C sequestration had reached their peaks, while nitrous oxide (N2O) emission continued rising as N was added. Since the early 2000s, stimulation of excessive N fertilizer uses to global climate warming through N2O emission was estimated to outweigh their climate benefit in increasing CO2 uptake. The net warming effect of N fertilizer uses, mainly centered in the North China Plain and the middle and lower reaches of Yangtze River Basin, with N2O emission completely counteracting or even exceeding, by more than a factor of 2, the CO2 sink. If we reduced the current N fertilizer level by 60% in ‘over-fertilized’ areas, N2O emission would substantially decrease without significantly influencing crop yield and soil C sequestration.