Study Of Agricultural Eco-Efficiency In Henan Province Based On Grey Water Footprint And Carbon Emissions

Since the reform and opening up 40 years ago,the agricultural economy has developed rapidly,and the problems such as ecological deterioration and resource waste brought about by it have become increasingly serious.At present,17% of greenhouse gases in China come from the agricultural sector,and agricultural carbon emissions have become an important source of carbon emissions in China.Excessive use of pesticides and fertilizers has also seriously affected water resources in China.Water pollution and greenhouse gas emission caused by agricultural production activities have become two key environmental problems,and the sustainable development of agriculture is facing severe challenges.As a major agricultural province,Henan is an important grain production base in China and the key to ensuring national food security.Promoting the sustainable development of agriculture in Henan is of great significance to the development of resource-saving and environment-friendly “two-oriented agriculture” in China.Therefore,it is of great theoretical and practical significance to improve agricultural eco-efficiency from the perspective of win-win economic and environmental benefits for solving the social contradiction between agricultural production and ecological environmental protection,promoting the implementation of agricultural sustainable development and ensuring food security.In this paper,the agricultural grey water footprint and carbon emission in Henan Province from 2001 to 2020 are calculated respectively,and the impact of agricultural production on water environment and climate is quantified.Secondly,the comprehensive environmental impact degree is defined,the agricultural economic growth with the comprehensive environmental impact degree are compared,and the development of agricultural eco-economy in Henan Province is evaluated.Grey water footprint and carbon emission are included in the evaluation index system of agricultural eco-efficiency,and the agricultural eco-efficiency of Henan province and its cities from 2001 to 2020 is calculated by using the super-efficiency SBM model.The spatial distribution and trend characteristics of agricultural eco-efficiency of cities in Henan province are visually analyzed by GIS technology,and the driving mechanism of spatial differentiation of agricultural eco-efficiency in Henan province is explored by using geographical detectors.By introducing kernel function,a grey BP neural network prediction model based on kernel function is constructed to predict the agricultural eco-efficiency and related indicators in Henan Province from 2021 to2025 to explore its development trend.Using the grey relational analysis model,the key influencing factors of agricultural eco-efficiency in Henan Province are screened out.The main conclusions are as follows:(1)By measuring the agricultural grey water footprint,it is found that from2001 to 2020,the agricultural grey water footprint in Henan Province came from phosphate fertilizer,and it increased first and then decreased.In 2020,the agricultural grey water footprint rebounded,but it was lower than the initial value in 2001.Except for the agricultural grey water footprint in western Henan,the grey water footprint in eastern Henan,southern Henan,northern Henan and central Henan all showed a changing trend of first increasing and then decreasing,and the grey water footprint peaked in different years.By measuring agricultural carbon emissions,it is found that chemical fertilizer is the main carbon source of agricultural carbon emissions in Henan Province,and the agricultural carbon emissions in Henan Province and the five major regions all show a changing trend of first rising and then falling,and the agricultural carbon emissions all reach the peak in different years.Comparing the degree of comprehensive environmental impact with the growth rate of agricultural output value,it is found that in recent years,agricultural production in Henan Province is in a state of “low pollution” and “high income”,and the degree of comprehensive environmental impact is decreasing.(2)Through the analysis of the spatio-temporal characteristics of agricultural eco-efficiency in Henan Province,it is found that: firstly,from 2001 to 2004,the agricultural eco-efficiency in Henan Province was just in an effective state;from 2005 to 2020,the agricultural eco-efficiency showed a “U” shape,and it was effective in2019;Secondly,there are more and more cities with effective agricultural eco-efficiency in Henan province,but the agricultural eco-efficiency in Anyang and Zhengzhou has always remained at a low level,and chemical fertilizer is the main reason for the ineffectiveness of agricultural eco-efficiency in these two cities;Thirdly,with the passage of time,in the east-west direction,the agricultural eco-efficiency has changed from a curve shape with high in the west and low in the east,slightly higher than both ends in the middle,to a “U” shape with high in the west and low in the east,and the linear shape with low in the north and high in the south has become more and more obvious in the north-south direction.Fourthly,the horizontal stratification of factors has a greater influence on the spatial differentiation of agricultural eco-efficiency in Henan Province than the spatial stratification,and the degree of explanation of agricultural input factors gradually weakens,and carbon emissions gradually become the most important factor of spatial differentiation of agricultural eco-efficiency.(3)It is verified that the newly constructed kernel optimized grey BP neural network model has higher accuracy and less limitations,and it is used to predict the agricultural ecoefficiency,agricultural grey water footprint and agricultural carbon emission in Henan Province from 2021 to 2025.It is found that the agricultural eco-efficiency in Henan Province has increased year by year,but the increasing range has gradually decreased.Agricultural grey water footprint is also gradually increasing;Agricultural carbon emissions show a downward trend,but the rate of decline gradually will decrease.Through the grey relational analysis of agricultural eco-efficiency in Henan province and its influencing factors,it is found that the number of agricultural employees,crop planting area,pesticide application,diesel application in endogenous factors and agricultural industrial structure and agricultural financial investment in exogenous factors are the key influencing factors of agricultural eco-efficiency in Henan province.Finally,the paper puts forward some countermeasures and suggestions to improve the agricultural eco-efficiency in Henan Province from four aspects:“reasonably investing in agricultural production factors,promoting the development of agricultural green technology”,“adjusting industrial structure,optimizing industrial structure”,“increasing financial support for agriculture,perfecting financial supervision mechanism”,“coordinating regional development and improving agricultural eco-efficiency”,which can provide ideas and decision-making reference for government departments to promote the sustainable development of agriculture.