Estimation of nitrous oxide, nitric oxide and ammonia emissions from croplands in East, Southeast and South Asia
Estimation of nitrous oxide, nitric oxide and ammonia emissions from croplands in East, Southeast and South Asia
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DOI：
10.1046/j.1365-2486.2003.00649.x
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发表时间：
2003-07-01
影响因子：
11.6
通讯作者：
Ohara, T
中科院分区：
文献类型：
--
作者：
Yan, XY;Akimoto, H;Ohara, T
农业活动极大地改变了全球氮循环，并产生了具有环境重要性的含氮气体。全球生产的化学氮肥有一半以上用于东亚、东南亚和南亚的作物生产，在这些地区水稻是营养的核心。通过考虑背景排放以及农田施氮（包括化学氮、动物粪便、生物固氮以及还田的作物残茬中的氮）所导致的排放，对该地区农田的一氧化二氮（N₂O）、一氧化氮（NO）和氨（NH₃）排放进行了估算。农田一氧化二氮和一氧化氮的背景排放通量分别估计为1.22千克氮/公顷·年和0.57千克氮/公顷·年。对旱地和稻田分别估算了肥料诱导排放因子。研究区域农田的一氧化二氮排放总量估计为119万吨氮/年，其中43%来自背景排放。然而，平均肥料诱导的一氧化二氮排放仅占施氮量的0.93%，低于政府间气候变化专门委员会（IPCC）默认的1.25%的值，这是因为稻田的排放因子较低。研究区域的一氧化氮排放总量为59.1万吨氮/年，其中40%来自背景排放。平均肥料诱导的一氧化氮排放因子为0.48%。氨排放总量估计为1180万吨氮/年。在研究区域，尿素和碳酸氢铵的使用以及水稻种植导致化学氮肥的氨平均损失率较高。利用全球土地利用数据库，以0.5度×0.5度的分辨率展示了排放情况。
Agricultural activities have greatly altered the global nitrogen (N) cycle and produced nitrogenous gases of environmental significance. More than half of all chemical N fertilizer produced globally is used in crop production in East, Southeast and South Asia, where rice is central to nutrition. Emissions of nitrous oxide (N2O), nitric oxide (NO) and ammonia (NH3) from croplands in this region were estimated by considering background emission and emissions resulting from N added to croplands, including chemical N, animal manure, biologically fixed N and N in crop residues returned to fields. Background emission fluxes of N2O and NO from croplands were estimated to be 1.22 and 0.57 kg N ha(-1)yr(-1), respectively. Separate fertilizer-induced emission factors were estimated for upland fields and rice fields. Total N2O emission from croplands in the study region was estimated to be 1.19 Tg N yr(-1), with 43% contributed by background emissions. The average fertilizer-induced N2O emission, however, accounts for only 0.93% of the applied N, which is less than the default IPCC value of 1.25%, because of the low emission factor from paddy fields. Total NO emission was 591 Gg N yr(-1) in the study region, with 40% from background emissions. The average fertilizer-induced NO emission factor was 0.48%. Total NH3 emission was estimated to be 11.8 Tg N yr(-1). The use of urea and ammonium bicarbonate and the cultivation of rice led to a high average NH3 loss rate from chemical N fertilizer in the study region. Emissions were displayed at a 0.5degrees x 0.5degrees resolution with the use of a global landuse database.