摘要
对川中丘陵区典型小流域农田生态系统N素收支分析表明,紫色土丘陵区农田N肥施用量较大,旱地、水田N肥年施用量分别为363.5kg/hm2和161.8kg/hm2,化肥N占小流域农田N素投入的76.65%。除作物收获外,小流域农田生态系统N素年损失量为129.67kg/hm2,且以气态损失为主,旱地农田通过径流、淋洗和泥沙等途径损失的N素年均44.34kg/hm2。小流域农田生态系统N素年均盈余66.8kg/hm2,农田N素盈余加剧了N素损失,并已造成小流域农业非点源N污染。
The nitrogen balance of agro-ecosystem in a typical watershed in the hilly area of central Sichuan Basin was studied. The results show that there is an excess application of nitrogen which is 363.Skg/hm^2 in dryland and 161.8 kg/hm^2 in paddy field, respectively. The chemical nitrogen accounts for 76.65% of the total nitrogen input to the agro ecosystem. Besides crops＇ harvest, nitrogen loss from agro-ecosystem amounts to 129.67kg/hm^2·a mainly by gas. Runoff, leaching and rail erosion are other important losses primarily from slope cropland which averages 44.34 kg/hm^2·a. The nitrogen surplus of agro-ecosystem in the small watershed is 66.8kg/hm^2·a, which increases the nitrogen loss and results in non-polnt source pollution of nitrogen to some extent in this watershed.
出处
《中国生态农业学报》
CAS
CSCD
2006年第1期108-111,共4页
Chinese Journal of Eco-Agriculture
基金
中国科学院知识创新工程项目(KZCX2-314)
中国科学院野外台站基金项目资助
关键词
农业生态系统
紫色土
小流域N素收支
Agro-ecosystem, Purple soil, Nitrogen input and output in small watershed
