Measurement Of Agricultural Green Total Factor Productivity Of Three Urban Agglomerations In The Yangtze River Economic Belt Facing Non-point Source Pollution

In recent years,China’s agricultural development has being a new phase,but meanwhile,the "hard constraints" of resources and environment faced by agricultural development have also intensified,such as the increasingly severe agricultural non-point source pollution.In this context,the traditional total factor productivity can not accurately measure the agricultural production efficiency,so we need to pay more and more attention to the agricultural green total factor productivity under the restrictions of environment and resources.Based on the panel data of 52 cities in Chengdu-Chongqing Urban Agglomeration,Triangle of Central China and Yangtze River Delta Urban Agglomeration in the Yangtze River economic belt from 2008 to 2017,this paper analyzes the temporal and structural characteristics of agricultural non-point source pollution,using BAM model and Luenberger productivity index model.This paper reveals the changes of agricultural production total factor inefficiency and agricultural green total factor productivity in the three urban agglomerations,and decomposes the agricultural green total factor productivity into factors and root causes.Further,for agricultural non-point source pollution,the variation of agricultural non-point source pollution(TN,TP,COD)is decomposed into the sum of individual effect,efficiency effect,benefit effect and scale effect by using lpi-lmdi model,and the contribution of each effect to the change of agricultural non-point source pollution emission in different time periods is discussed.The results show that:(1)in the Yangtze River Economic Belt,the emissions of agricultural non-point source pollutants(TN,TP and COD)in the three urban agglomerations generally show an upward trend,and the total amount and growth rate of agricultural non-point source pollution of the Yangtze River Delta Urban Agglomeration are much lower than those of the other two urban agglomerations;From the perspective of agricultural non-point source pollution emission structure,agricultural solid waste is the main source of agricultural non-point source pollution,accounting for more than 90% of the total pollution emission;(2)The overall inefficiency value of the Yangtze River Delta Urban Agglomeration is the lowest,and the overall inefficiency value of Triangle of Central China is the highest.Among them,the sowing area of crops,the number of agricultural employees,the power of agricultural machinery and the application amount of chemical fertilizer are important factors leading to the inefficiency of agricultural production.The ineffective rate values of TN、TP and COD of Triangle of Central China reaches0.06,0.04 and 0.06.Attention should be paid to the agricultural non-point source pollution;(3)From 2008 to 2017,the agricultural green total factor productivity of the Yangtze River Delta Urban Agglomeration and Chengdu-Chongqing Urban Agglomeration showed an overall growth trend(the growth rates were 2.65% and1.96% respectively),and the total factor productivity of Triangle of Central China decreased slightly(-0.04%).From the perspective of factor decomposition,the contribution of agricultural non-point source pollution to the growth rate of the Yangtze River Delta Urban Agglomeration,Chengdu-Chongqing Urban Agglomeration and Triangle of Central China is 0.91%,0.70% and-0.06%respectively.The government should strengthen the control of agricultural non-point source pollution in Triangle of Central China;From the perspective of root cause decomposition,the growth of agricultural total factor productivity is mainly driven by pure technological progress.Technical efficiency(including pure technical efficiency and scale technical efficiency)restricts the improvement of agricultural green total factor productivity for a long time.Scale technological progress has a positive impact on the total factor productivity of Chengdu-Chongqing Urban Agglomeration and Yangtze River Delta Urban Agglomeration,and a negative impact on Triangle of Central China;(4)Benefit effect is the main factor affecting the increase of agricultural non-point source pollution in the three urban agglomerations;Efficiency effect is the leading factor of agricultural non-point source pollution reduction in Chengdu-Chongqing Urban Agglomeration and Yangtze River Delta Urban Agglomeration,but it promotes the pollution emission of Triangle of Central China;The overall impact of scale effect and individual effect is relatively insignificant.Based on the above analysis results,this paper puts forward three suggestions:(1)Strengthen the innovation and popularization of agricultural science and technology,and improve technological progress and technological efficiency;(2)Accelerate the implementation of environmental protection policies,and strengthen the treatment of agricultural non-point source pollution;(3)Foster new types of agricultural business entities,and promote appropriate scale agricultural management.