基于耕地承载力的畜禽养殖污染负荷及环境风险研究——以四川省为例

Pollutant Loads and Environmental Risks of Livestock Production Based on Arable Land Carrying Capacity——A Case Study in Sichuan Province

[目的]通过对四川省畜禽养殖污染负荷、耕地承载力空间分布特征的探讨,为研究区农业的可持续发展提供理论依据。[方法]在前人研究基础上,结合四川省区域特点,研究各市州畜禽粪便产生量、主要污染物产生量、流失量以及单位耕地面积猪当量负荷量,N和P负荷量,利用ArcGIS解析其空间分布特征,对耕地承载力现状进行风险评价。[结果]2016年四川省畜禽粪便总产量2.94×10~7 t;产生和流失最多的污染物为化学需氧量(COD),最少为全磷。四川省单位耕地面积猪当量负荷,N,P负荷平均值分别为50 310,327,85kg/hm^2,平均负荷预警值1.34,风险评价等级Ⅳ级,对环境有威胁。但负荷预警值在区内存在空间分布不均的特征,阿坝州和甘孜州最高,预警值分别为6.61和6.93,均属Ⅵ级,对环境构成严重威胁。[结论]现阶段畜禽粪便的产生已对四川省环境有威胁,畜禽粪便污染的来源主要是牛粪和猪粪。应推广农牧结合、种养平衡、生态循环的畜禽养殖模式。

[Objective]To investigate the pollution distribution of livestock production and the spatial distribution characteristics of arable land carrying capacity in Sichuan Province,in order to provide a theoretical basis for sustainable development of agriculture in this area.[Methods]Total livestock manure production,the losses of manure pollutants,and the availability of agricultural lands were estimated.The ArcGIS was used to evaluate land resource requirements and environmental risks of livestock production,as well as agricultural carrying capacity.[Results]Total livestock manure production in Sichuan Province was 2.94×10~7 t in 2016.The losses of pollutants were dominated by COD(chemical oxygen demand,not a pollutant),while the least was total phosphorus(TP).The average PEL(pig equivalent load),nitrogen(N)and phosphorus(P)carrying capacity was 50 310,327,and 85 kg/hm^2,respectively,resulting in an average risk threshold value of 1.34(gradeⅣ).However,the load warming values varied greatly across the region,with the highest in Aba(6.61)and Ganzi(6.93).[Conclusion]At present,the production of livestock and poultry manure has been a threat to the environment in Sichuan Province,the source of livestock and poultry manure pollution is mainly cow dung and pig dung.The model of livestock and poultry breeding in the combination of agriculture and pastoral,breeding and ecological circulation should be promoted.