广西九洲江流域限制生猪养殖的机会成本与环境效益分析

作为生态补偿试点之一,九洲江流域禁养、限制生猪养殖取得了一定的环境效益,但同时造成直接经济损失约1.49亿元。以满足水环境容量的养殖规模125.00万头为基准,设定维持现有养殖模式、转变养殖模式2种情景,计算限制生猪养殖的机会成本与环境效益。结果表明,与畜牧业发展规划的养殖规模260.00万头相比,机会成本约7.36亿～7.74亿元。转变养殖模式的环境效益优于维持现有养殖模式,污染物减排量分别为COD 26 995.54t、氨氮2 411.92t、TP 2 107.80t、TN 5 300.71t,节水1 251.39万m^3;在优选情景方案下,要求200头以上养殖户100%转变为高架网床养殖模式,机会成本约7.36亿元。

Opportunity costs and environmental benefits of pig breeding restriction in the Jiuzhoujiang basin of Guangxi

The restriction of pig-breeding in the Jiuzhoujiang basin had obvious environmental benefits,while the direct economic losses reached 1.49×10^9 yuan.The opportunity costs and environmental benefits were predicted in the two scenarios,maintaining and transforming the existed breeding pattern at a breeding scale of 1.25 million pigs under the environmental capacity.The results showed that the opportunity costs would be 7.36×10^9-7.74×10^9 yuan comparing with the planned maximum breeding scale of 2.60 million.The environmental benefits of transforming breeding pattern were better than those of the existed breeding pattern,with COD,ammonia nitrogen,TP,TN emission reduction of 26 995.54,2 411.92,2 107.80 and 5 300.71 t respectively,water saving of 1.251 39×10^7 m^3.In the optimal scenario,the opportunity costs would be 7.36×10^9 yuan if farmers whose breeding scale were over 200 pigs transformed to elevated-bed-breeding pattern.