Research On Environmental Efficiency And Influencing Factors Of Livestock And Poultry Breeding From The Perspective Of Grey Water Footprint In China

The report of the 19 th National Congress clearly pointed out that we should focus on solving outstanding environmental problems and speeding up the prevention and control of water pollution.It haves been an important task to promote the construction of ecological green civilization by strengthening the prevention and control of water pollution in livestock and poultry breeding.At present,the pollution situation of agricultural surface is very serious,and livestock and poultry breeding is the largest source of agricultural surface pollution.COD emissions of livestock and poultry breeding account for about 90% of total agricultural COD emissions,which poses a huge threat to human production and domestic water.With the large-scale and intensive development of livestock and poultry breeding industry in China,the discharge of livestock manure and the concentration of emissions is increasing,but the comprehensive utilization rate of manure resources is low,and the pollution to the water environment is very serious.Effectively managing water pollution in livestock and poultry breeding is an inevitable path to practice the concept of green development and promote the shift of agriculture to green development.Based on water footprint theory,total factor productivity theory and scale economy theory,this paper constructs a grey water footprint measurement system for livestock and poultry breeding,and calculates the grey water footprint of pigs and laying hens breeding under different breeding scales in 2007-2016;Takes the grey water footprint of livestock and poultry breeding as undesired output,and uses the ultra-efficient SBM model to measure the environmental efficiency of pigs and laying hens under the common frontier and group frontier,and analyzes the trend of technical drop ratio;establishes the panel Tobit regress model,and empirically analyzes the influencing factors of the environmental efficiency of livestock and poultry breeding from six aspects of individual characteristics of livestock and poultry,ratio of concentrate feed,regional production structure,culture technology,market price and environmental regulation.Through empirical analysis,the paper draws the following conclusions:(1)The larger the scale of livestock and poultry breeding,the smaller the average grey water footprint,and the greater the pollution pressure on the water environment,and grey water footprint of livestock and poultry breeding is generally high in the east and low in the west;(2)The environmental efficiency of large-scale livestock and poultry breeding under the common frontier is higher than that of small-scale and medium-scale livestock and poultry breeding,and there are certain regional differences in environmental efficiency under different breeding scales.(3)Large-scale livestock and poultry breeding is closer to the optimal technical level,and the technical heterogeneity between different breeding scales is weakening.The technical heterogeneity of laying hens is more obvious than that of pigs;(4)The concentrated feed rate has a significant negative impact on the environmental efficiency of pig breeding,and the culture technology has a significant positive impact;the concentrated feed rate,regional production structure,culture technology and environmental regulation have a significant positive impact on the environmental efficiency of laying hens.Prices have a significant negative impact.