Sustainability Of Farming System In Jiangsu Province Based On Emergy Analysis

Green agriculture is a new model of modern agriculture development.Actively developing green agriculture is of great significance to ensuring national food security and promoting sustainable development of society and economy.Jiangsu province is located in the lower reaches of Jianghuai River and the vast plain,suitable for cultivation,is one of the 13 main grain production provinces in China,with its unique ecological and environmental basis.Based on agricultural statistics and literature,this study constructed an energy value model of tillage system.Taking the tillage system of Jiangsu province as the research object,the spatiotemporal change of energy value of tillage system and the green GDP of tillage operation in Jiangsu province since the 1990s were analyzed.Based on the sensitivity of energy sustainability and the identification of green GDP impact factors,this paper explores the evolution mechanism and optimal regulation of the sustainable development of farming systems in Jiangsu province.The main conclusions are as follows:(1)the total input of cultivated land energy in jiangsu province has been on a slow rise since the 1990s;The trend of non-renewable industrial auxiliary energy is basically the same as that of renewable organic energy.In 2017,in the energy-value input of cities and counties in Jiangsu province,renewable resource input and non-renewable resource input were affected by the area of cultivated land.The counties with higher levels were more concentrated in the central coastal areas and the inland areas in northern Jiangsu.The non-renewable industrial auxiliary energy and renewable organic energy input showed a transition trend from south to north.(2)The total output of cultivated land energy in Jiangsu province fluctuated from the 1990s to the early 21st century,and reached the bottom in 2003,then gradually recovered and rose.The net energy yield is consistent with it.In 2017,the total output of energy value of cities and counties in Jiangsu province was higher than that of southern Jiangsu.The output of labor energy value was higher than the provincial average in northern Jiangsu,and the output of average net energy value was higher than the average in central and northern Jiangsu.(3)The environmental load rate of cultivated land system in Jiangsu province has been increasing first and then decreasing since 1990s,but it has been in the stage of less pressure all the time.The average environmental load rate of Jiangsu province shows that the overall pressure on the environment is small and there is still room for development.The area of high pressure is mainly distributed in the south of Jiangsu province(4)The sustainable development index of cultivated land in Jiangsu province has been full of vitality since 1990,and the cultivated land system is within the range of strong sustainable development ability,but the sustainable development ability has decreased since 2003.In 2017,the sustainable development index of most counties and districts in Jiangsu province was in a low range,indicating that Jiangsu province as a whole still belongs to the consumption-oriented eco-economic system(5)Since the 1990s,both the traditional GDP and the green GDP of Jiangsu province have been increasing year by year,especially in recent years.However,the proportion of green GDP in traditional GDP has been decreasing year by year,and the decline is large Fortunately,it has slowed down in recent years.In 2017,the per capita green GDP of all counties and cities in Jiangsu province was consistent with the per capita traditional GDP,with high GDP in southern and central Jiangsu.(6)The non-renewable natural resources in Jiangsu province have changed almost negligible since the 1990s,but their share in traditional GDP has been declining year by year until 2016.Nonrenewable natural resources in 2017 counties of Jiangsu province city of traditional GDP and Xishan district,Wuxi municipal districts is the smallest area in Wuzhong district of Suzhou municipal districts,and Wujiang district,Changzhou Wujin district and Huaian Hongze county,Huaian Lianshui county,is the biggest area of Yancheng Dafeng,Dongtai and Yandu district of Yangzhou Baoying and Gaoyou,Taixing city of Taizhou and Nantong Tongzhou district and Qidong and Jiangyan area,the main changes associated with local farming land area.(7)Since 1990,the non-renewable industrial auxiliary energy in Jiangsu province has increased with the increase of traditional GDP,and the trend is relatively consistent.Since the early 21st century,it has increased sharply.With the increase of non-renewable industrial auxiliary energy,its proportion in traditional GDP is also increasing year by year,but the increase in the past decade is small and a small part of the decline.In 2017,the proportion of non-renewable industrial auxiliary energy of all counties and cities in Jiangsu province was more than half,mainly concentrated in Wuxi,Suzhou and Changzhou.Except for the municipal districts,the proportion was all higher than the average of Jiangsu province.(8)The environmental loss of Jiangsu province is not big for the traditional GDP,but it cannot be ignored.Since 1990,the proportion of environmental loss has fluctuated.In 2017,the regions with serious environmental loss in all counties and cities of Jiangsu province were mainly concentrated in the north-central part of Jiangsu province,and most of the southern part of Jiangsu province was in good condition(9)The energy value sustainability of farming system in Jiangsu province has a low sensitivity to renewable resources and renewable organic energy and is positively correlated.The highest sensitivity is non-renewable industrial auxiliary energy,which is inversely proportional to non-renewable industrial auxiliary energy.The increase of non-renewable industrial auxiliary energy is mainly due to its strong dependence on purchasing energy value(mainly chemical fertilizer and electric power),followed by agricultural machinery and diesel oil.The factors that influence the green GDP of Jiangsu province include not only the natural environment,but also the auxiliary energy factors of external input.Among them,fertilizer,pesticide,agricultural film,mechanical power,electricity and diesel account for a large proportion,and labor input has the lowest influence.