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Nitrogen budgets of agricultural fields of the Changjiang River basin from 1980 to 1990

文献类型：EI期刊论文

作者Liu Jiyuan
发表日期2006
关键词Agriculture Database systems Environmental impact Fertilizers Nitrogen Rivers
英文摘要To assess the fate of the large amounts of nitrogen (N) brought into the agricultural environment by human activities in the Changjiang River basin, we used [China's county level agricultural database of 1980 and 1990. National Resources and Environmental Data Center, China] and published conversion data to set up a complete N budget for the Changjiang River basin. Sources considered include imported N such as atmospheric deposition, inorganic fertilizer, biological fixation and manure. Dominant losses considered include crop harvests, denitrification of soil nitrate and NH3 volatilization, and the budget was estimated from the difference between all inputs and all outputs. Therefore, the geographic distribution of excess N, considered as lost, by N storage in farmland and N transported to water bodies in Changjiang River basin was analyzed. In the Changjiang River basin, the anthropogenic reactive N has far exceeded the terrestrial bio-fixed N in nature, and human activities have significantly altered the N cycle in this region. The total inputs of N in 1980 and 1990 were 8.0 and 12.9 Tg N, respectively. The total N outputs are 4.41 Tg N in 1980 and 6.85 Tg N in 1990. Thus, the excess N that was stored in farmland was 1.51 Tg N at 1980 and 2.67 Tg N at 1990, respectively, and losses through transportation to water bodies in 1980 was 2.08 and 3.38 Tg N in 1990, respectively. Our research shows that from 1980 to 1990, cultivated land increased 5.9%, grain production increased 30% and N fertilizer-use increased 106%, but the N fertilizer-use efficiency decreased 36%, and the variations in the distribution of N fertilizer-use efficiency, N budgets and N transport to water bodies tended to coincide with each other geographically. © 2005 Elsevier B.V. All rights reserved.
出处Science of the Total Environment
卷363期:1-3页:136-148
收录类别EI
语种英语
源URL[http://ir.igsnrr.ac.cn/handle/311030/25022]  
专题地理科学与资源研究所_历年回溯文献
推荐引用方式
GB/T 7714		 Liu Jiyuan. Nitrogen budgets of agricultural fields of the Changjiang River basin from 1980 to 1990. 2006.

入库方式： OAI收割

来源：地理科学与资源研究所

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