%0 Journal Article
%T A case study on non-point source pollution and environmental carrying capacity of animal raising industry in subtropical watershed<br>亚热带流域氮磷排放与养殖业环境承载力实例研究
%A MENG Cen
%A LI Yuyuan
%A XU Xiaoguang
%A GAO Ru
%A WANG Yi
%A ZHANG Manyi
%A WU Jinshui
%A <br>孟岑
%A 李裕元
%A 许晓光
%A 高茹
%A 王毅
%A 张满意
%A 吴金水
%J 环境科学学报
%D 2013
%I 
%X The discharge of faeces from animal production is a major source of nitrogen (N) and phosphorus (P) pollutants in the subtropical region of China. To quantify the N and P load from animal production to hydro-systems in the region, surveys on pig density and N,P inputs to farmlands, soil N and P contents, and annual observations of the N and P flows in the streams and the terminal river were carried out in a hilly watershed (134.4 km2) in Changsha County, Hunan Province. It was showed that the total NP loads from the watershed to the terminal river was 2.72 t and 0.11 t·km-2·a-1, respectively; within which 42.2% of the N and 62.0% of the P were loaded from animal production sites. The mean animal density in the watershed was currently 3.46 AU·hm-2. The current NP inputs to farmlands was 35.8 kg and 18.6 kg·hm-2 in the watershed. Based on an estimate for the environmental adaptation capacity (EAC) of N and P in the watershed, the current animal density was 2.4 times larger than the critical density (1.13 AU·hm-2) of the EAC for the watershed under the current N and P fertilizer inputs levels. Assuming that 30% of N discharge for animal production is re-used by farmlands, the animal density under the EAC can be set at 2.74 AU·hm-2 (equivalent to 195,000 pigs for slaughter every year). Thus, we propose to reconstruct the agricultural systems by reducing animal production and establishing an integrating crop and animal farming systems.
%K subtropical watershed
%K animal density
%K nitrogen and phosphorus load
%K environmental adaptation capacity<br>亚热带流域
%K 畜禽养殖密度
%K 氮磷负荷
%K 环境承载力
%U http://www.alljournals.cn/get_abstract_url.aspx?pcid=3FF3ABA7486768130C3FF830376F43B398E0C97F0FF2DD53&cid=A7CA601309F5FED03C078BCE383971DC&jid=03A55E61A8750ACAC6AF81EF9E2AC838&aid=9C65539B20E123FC8A73C56806817E57&yid=FF7AA908D58E97FA&vid=27746BCEEE58E9DC&iid=0B39A22176CE99FB&sid=20C9FB8C7B4A22AD&eid=5DD21DF25EF52D4A&journal_id=0253-2468&journal_name=环境科学学报&referenced_num=0&reference_num=27