Abstract: In order to realize the regional balance structure and coordinated development of crop and livestock,based on the Statistical Yearbook of Gongan County 2017,the nitrogen demand for crops and the nitrogen supply from fertilizer and straw returning and environmental carrying capacity of livestock and poultry were estimated and analyzed.Then,the pollution risk of livestock and poultry breeding were analyzed by using modified nutrient balance method.The results showed that,the environmental carrying capacity of livestock and poultry in Gong’an County was 11.56 head/ha(the pig equivalent),and the actual livestock and poultry amount per unit area was 9.17 head/ha(the pig equivalent).Which meant the environmental carrying capacity of livestock and poultry was more than the actual livestock and poultry amount per unit area,and the environmental pressure in livestock and poultry breeding was low;The nitrogen pollution in livestock and poultry breeding per unit area of Gong’an County was 125.77 kg/ha.Among it,Mengjiaxi Town,Yangjiachang Town,Jiazhuyuan Town were 226.06,183.88,179.65 kg/ha respectively,which exceeded the EU limit standard(170.00 kg/ha),while other towns were below it;The pollution risk of livestock and poultry breeding was 0.79 in Gong’an County,but there were great differences between different towns,ranged from 0.31 to 7.69.Among it,the pollution risk of livestock and poultry breeding was the biggest (7.69) in Jiazhuyuan Town. The pollution risk of livestock and poultry breeding were 1.85,1.70 respectively in Zakou Town and in Douhudi Town,that ment livestock and poultry breeding would be risk.The pollution risk of livestock and poultry breeding were less than 1.00 in the other towns,that meant livestock and poultry breeding was relatively safe for the environment.

Key words: Nitrogen nutrient balance method, Livestock and poultry breeding, Environmental carrying capacity, Actual livestock and poultry amount, Nitrogen pollution of livestock and poultry breeding in unit area;Pollution risk of livestock and poultry breeding, Structure of crop and livestock, Gong’an County

摘要： 湖北公安县地处的洞庭湖水系敏感区,为实现区域内种养结构平衡,以《公安县统计年鉴2017》为基础,对区域内作物生长对氮养分的需求量、区域内化肥使用为作物生长提供的氮养分供给量、秸秆还田为作物生长提供的氮养分供给量、畜禽养殖环境承载力进行估算分析,采用修正后的氮养分平衡法评价畜禽养殖污染风险。结果表明,公安县畜禽养殖环境承载力为11.56 头/hm²(猪当量) ,单位面积实际畜禽量为9.17 头/hm²(猪当量) ,小于单位面积畜禽养殖环境承载力,畜禽养殖环境压力较小;公安县单位面积畜禽养殖氮污染量为125.77 kg/hm²。其中,孟家溪镇、杨家厂镇、夹竹园镇分别为226.06、183.88、179.65 kg/hm² ,均超出了欧盟限制标准(170.00 kg/hm²) ,其他乡镇均在欧盟限制标准以下; 公安县畜禽养殖污染风险为0.79, 但各乡镇差别较大, 介于0.31~7.69。其中,夹竹园镇畜禽养殖风险最大,为7.69,闸口镇、斗湖堤镇畜禽养殖风险分别为1.85、1.70,存在一定风险,其他乡镇畜禽养殖风险均小于1.00,畜禽养殖对环境来说安全。

关键词: 氮养分平衡法, 畜禽养殖, 环境承载力, 实际畜禽量, 单位面积畜禽养殖氮污染, 畜禽养殖污染风险, 种养结构;公安县