基于碳—水足迹的畜禽养殖环境承载力估算OA

Regional balance between planting and breeding is an important goal of green agricultural development.Pollution to the atmosphere and water environment caused by breeding is one of the factors restricting the green and efficient development of animal breeding industry.This paper conducted modeling work of the environmental bearing capacity of animal farming,evaluated the appropriate breeding volume in the region,and provided a reference for regional balance between planting and breeding and environmental protection.The animal breeding production system in the North China Plain was taken as the research object.The results of the second national pollution source census were used to calculate the carbon footprint and grey water footprint of the animal breeding industry in 2017.According to the regional water environment,atmospheric environment,farmland nutrients and policy-oriented constraints,the linear programming and scenario analysis methods were used to model and simulate the environmental bearing capacity of animal farming in the North China Plain.The results showed that based on the evaluation and optimization of carbon footprint and grey water footprint,the environmental bearing capacity of animal farming in Beijing,Tianjin,Hebei Province,Shandong Province and Henan Province was 10 million,20 million,290 million,580 million and 1.03 billion heads respectively,which far exceeded the current breeding volume and were not overloaded.When the water environment pressure increased,the environmental bearing capacity of animal farming showed a downward trend.When the ammonia nitrogen emissions from water pollutants of animal breeding industry were reduced by 50%,the environmental bearing capacity of animal farming in the North China Plain increased to 2.04 billion heads,an increase of 66.7%;once the surface water resources began to decrease,the animal bearing capacity was constrained because it was lower than the policy-guided value.It could be seen that reducing the discharge of water pollutants alleviated the pressure of water shortage in the North China Plain on the development of animal breeding industry.It was recommended that animal farms should strengthen anaerobic fermentation engineering facilities,reduced the emission of water pollutants such as ammonia nitrogen;the government should increase subsidies for the purchase and production of agricultural machinery for returning manure to the fields,to achieve efficient return of manure to the fields;green accounts should be established for farms,and fiscal means should be used to guide the green transformation of the industry.