| China is a populous country and needs lots of food,the production and quality problems of food have received the attention of people.In recent years,food produc-tion has grown steadily,and has basically achieved self-sufficiency.The result behind the increase of food is deterioration of agricultural ecological environment.The sus-tainability of the food production began to be limited by land resource endowment and the ecological environment.The pressure caused by deterioration of the ecologi-cal forced people to give up something.Therefore,in January 2002,China started the project of returning farmland to forest and grass.Meanwhile,China also began to use administrative intervention measures to maintain the ecological balance.Although grain production achieved in successive increase,the environmental deterioration and environmental pressure caused by agricultural production made people nervous.Relying on inputs such as fertilizers,pesticides and herbicides to increase food production,will form a vicious circle of "drug abuse".Finally,soil will lose all the growing conditions of crops.Because the seriousness and urgency of fertilizer and pesticide pollution,in February 2015,China has established the fertilizer and pesti-cides use zero growth in 2020 action plan.Compared with countries whose economic development are similar to China,the ecological efficiency level of our country is the lowest in the BRICS,which is also less than most countries around the world.There-fore,our country's ecological efficiency has lots of things to do and study.People pay attention to food security,and hope to reduce agricultural pollution.These two problems are connected but conflict to each other.The conclusion without anyone is partial.If put ecological safety aside,considering the problem of food secu-rity with short-term food balance of supply and demand,will come to blindly optim-ism conclusion.If put food security threat aside to think the problem of ecological security,then we are unable to get the feasible solution.From the view of system theory,putting these two problems in the same framework for research,then we will find the way to solve the problem.Under the circumstances,this paper tries to discuss and answer the following questions.In recent years,the input and applying strength of China's grain planting area and yield and the main factors of petrochemical(fertilizers and pesticides)?Con-sidering the economic factors and environmental factors of grain plant,how are the ecological efficiency and trends of every provinces in China's grain cultivation?What's the composition and result of the efficiency loss of inefficient provinces?What is the dynamic evolution trend of interprovincial grain planting eco-efficiency?Is there a spatial correlation between the eco-efficiency of interprovincial grain plant-ing?What factors will affect the changes in the ecological efficiency of grain planting in China?In order to answer the above questions,this paper focuses on the research main line of "input and output analysis-efficiency measurement and evaluation-dy-namic evolution analysis-influencing factors research-countermeasures",mainly using SBM(Slacks-based Measure)evaluation model,PS(Phillips&Sul)conver-gence model and spatial econometric model,to make the evaluation of ecological ef-ficiency of grain planting in China,to make the dynamic evolution analysis and to research influencing factors.The main contents and conclusions of the above studies are as follows:Research content 1:the input and output of Chinese grain plantation.This part investigated and finished the input and output of crops of China from 1990 to 2015.In detail,in this time,the grain planting area showed inverted "U" type trend,which is increase after reduction.The total grain increased with fluctuation.The increase of corn production contributed largely to the total grain output promo-tion,the next is wheat,rice,potato and the soybean.The output growth in major grain-producing areas was more than secondary grain producing areas.In 2015,the proportion of the major grain producing areas increased was 76%.Throughout the year of 201 5,China's fertilizer input reached 40.4 million tons.In 2007,using intensi-ty of food crops reached the peak which was 68.34 kg/ton(fertilizer/food).The input of pesticides increased fluctuantly.In 2009,for the periodic high(928600 tons),in 2014 to a peak(1.1926 million tons),after 2014,has a downward trend.Research content 2:measuring China's grain planting ecological efficiency.Putting pollutants discharge,grain output and the inputs in a unified framework,and then applied the SBM model to calculate grain plant ecological efficiency condi-tion of every provinces from 1990 to 2015.From the changing trend of the data,eco-logical efficiency,pure technical efficiency and scale effect are falling in a fluctuant way.The volatility of ecological efficiency is the largest,then is pure technical effi-ciency,and scale effect is minimal.The results of the SBM model calculation showed that labour,agricultural machinery and pesticide input redundancy are the main rea-sons lead to China's food plant ecological efficiency invalid.The use of land re-sources in some provinces is also inadequate,such as Yunnan,Shanxi,Shanxi,etc;The agricultural utilization efficiency in some provinces of is low,such as Liaoning province and Fujian province.From the perspective of the redundancy rate of the un-expected output,the redundancy rate of total nitrogen and total phosphorus of most of the provinces is higher.Using output oriented SBM model calculation,the results showed that in Yunnan province,Hebei province,Shanxi Province and Fujian prov-ince,grain output lost seriously,four provinces lost totaling 203.35 million tons.However,this condition showed that t there is still room for the growth of China's grain output.Food production in the province should focus on mining the potential output,and promoting optimization allocation of local grain resources,by increasing grain output increase ecological efficiency.Research content 3:The dynamic evolution analysis of the ecological efficiency of grain planting in China.In this chapter,the data analysis of representative years shows that the ecological efficiency of grain planting in China shows obvious regional characteristics.This means there is a gradient change from west to east—ecological efficiency in west is higher than the middle's and the middle's is higher than the east's.By using the ?convergence method to test the eco-efficiency of inter-provincial grain planting in China,this paper find that there is no overall convergence at the national level.The nuclear density map also believes that there is no overall convergence at the national level.But the eco-efficiency value of inter-provincial grain planting during the inspec-tion period presented the clear continued "double peak" pattern,this indicates that some provinces converge to "high value" and the others converges to "low value",which is there may be two types of "club convergence".Based on the heterogeneity-hypothesis PS convergence model,it is concluded that there is no overall convergence of the eco-efficiency of food planting in 31 provinces in China from 1990 to 2015,but two club convergence types are formed,which further clarifies the regional conditions of the two clubs..Research content 4:the influence factors of grain plant ecological efficiency in China.On the basis of theoretical analysis,these part did empirical study.There is a posi-tive correlation between provinces in China's grain planting ecological efficiency in space.Therefore,the spatial econometric model is more reasonable.The regression results of the Spatial Durbin Model showed that farmers' per capital disposable in-come,per capital arable land area of grain plant ecological efficiency of this area form a significant negative impact.The growth of Agricultural technical personnel was sig-nificantly beneficial to food crops in the region ecological efficiency.Industrial struc-ture level,the strength of financial support to agriculture had significantly positive effect to neighboring provinces,which is better "spillover" effect for peripheral prov-inces.From the point of the total effect,per capital disposable income of farmers caused negative influence on grain cultivation ecological efficiency.Farmers per capi-tal are fixed number of year of the education,the level of industrial structure level and the finance support agriculture positively influenced the grain plant ecological effi-ciency. |
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