%0 Journal Article
%T N biogeochemical cycle and its impacts on environments in an agro-forest ecosystem<br>农林复合生态系统氮素生物地球化学循环及其环境影响研究
%A PENG Kui
%A OUYANG Hua
%A ZHU Bo
%A <br>彭奎
%A 欧阳华
%A 朱波
%J 中国生态农业学报
%D 2005
%I 
%X The N balance and its pollution characteristics on enviro nments in a typical agro -forestry ecosy stem in the upper reaches of the Yangtze River were studied.The results show tha t in ecosystem,there is relatively high N surplus in croplands,almost N balance in paddies and high N deficit in forest. N balance appraisals show the N balance rate of croplands is reasonable but that of paddies shows a little higher.Howeve r,N balance of the whole arable lands ha s changed greatly from heavy deficit of 1960s to reasonable balance of nowadays. Forest and cultivations play the importa nt roles in the N balance changes of eco system.But the great increases of chemic al N fertilizer usages lead to the incre asing of the gas N emissions and N non -p oint source pollutions risk of water bod ies.
%K Agro
%K -forest
%K eco system
%K N balance
%K Biogeochemistry
%K Non
%K -point
%K source
%K pollution<br>农林复合系统
%K N素收支平衡
%K 生物地球化学
%K 非点源污染
%U http://www.alljournals.cn/get_abstract_url.aspx?pcid=03F54A49DE00578AA0E5DDF5BC021AA7&cid=1A8B5357F0EF07B8&jid=AB3ABF502E2E1FF39F0E3B80164C9031&aid=6B698D5555595FA9&yid=2DD7160C83D0ACED&vid=FC0714F8D2EB605D&iid=CA4FD0336C81A37A&sid=480C51B1F0CE0AB6&eid=EDA22B444205D04A&journal_id=1671-3990&journal_name=中国生态农业学报&referenced_num=0&reference_num=15