An inventory of N₂O emissions from agriculture in China using precipitation-rectified emission factor and background emission

详细信息	查看全文 | 推荐本文 |

• 作者：Yanyu Lu ; Yao Huang ; Jianwen Zou ; Xunhua Zheng
• 关键词：Emission factor ; Background emission ; IPCC methodology ; Nitrous oxide ; Precipitation ; Uncertainty
• 刊名：Chemosphere
• 出版年：2006
• 期刊代码：15_00456535
• 类别：env
• 出版时间：December 2006
• 卷：65
• 期：11
• 页码：1915-1924
• 文件大小：340 K

摘要

Fertilized agricultural soils are a major anthropogenic source of atmospheric N₂O. A credible national inventory of agricultural N₂O emission would benefit its global strength estimate. We compiled a worldwide database of N₂O emissions from fertilized fields that were consecutively measured for more than or close to one year. Both nitrogen input (N) and precipitation (P) were found to be largely responsible for temporal and spatial variabilities in annual N₂O fluxes (N₂O–N). Thus, we established an empirical model (N₂O–N = 1.49 P + 0.0186 P · N), in which both emission factor and background emission for N₂O were rectified by precipitation. In this model, annual N₂O emission consists of a background emission of 1.49 P and a fertilizer-induced emission of 0.0186 P · N. We used this model to develop a spatial inventory at the 10 × 10 km scale of direct N₂O emissions from agriculture in China. N₂O emissions from rice paddies were separately quantified using a cropping-specific emission factor. Annual fertilizer-induced N₂O emissions amounted to 198.89 Gg N₂O–N in 1997, consisting of 18.50 Gg N₂O–N from rice paddies and 180.39 Gg N₂O–N from fertilized uplands. Annual background emissions and total emissions of N₂O from agriculture were estimated to be 92.78 Gg N₂O–N and 291.67 Gg N₂O–N, respectively. The annual direct N₂O emission accounted for 0.92%of the applied N with an uncertainty of 29%. The highest N₂O fluxes occurred in East China as compared with the least fluxes in West China.