Transfer Pattern And Optimization Analysis Of Embodied Soil Erosion In Provincial Cereal Trade

Soil erosion reduces the productivity of cropland,threatens the sustainable development of agriculture and national food security.Trades transfer products,as well as embodied environmental effect in products from production places to consumption places.Existing governance patterns don’t allocate the responsibilities for soil erosion to consumers who buy cereal products,thus makes them lack motivation to participate in the prevention or control of soil erosion.However,consumption drives production,soil erosion caused by cereal production cannot effectively prevent or control only from the producers’perspective.In order to clarify the responsibility in soil erosion control,and explore more accurate soil erosion prevention and control strategies,it is necessary to identify the embodied soil erosion transfer in provincial cereal trade and provide scientific reference to soil erosion control in China.In this study,we evaluated the temporal and spatial distribution of soil erosion caused by cereal production in China from 2000 to 2015 by using the Revised Universal Soil Loss Equation(RUSLE).Then we calculated the amount of soil erosion caused by one unit of cereal production.And we combined the amount of soil erosion caused by one unit of cereal production with the provincial cereal trade network simulated by the linear programming optimization model to reveal the temporal and spatial pattern of embodied soil erosion transfer in provincial cereal trade.Finally,based on the provincial cereal trade pattern in2015,we put forward the possible optimization ideas of cereal trade pattern from both of the supply and demand perspective,respectively,to reduce soil erosion in China.The main results of this paper are as follows:(1)The evaluation result of soil erosion caused by cereal production showed that:from2000-2015,the amount of soil erosion caused by cereal production increased in China,while the amount of soil erosion caused by one unit of cereal production decreased.However,their spatial distributions were different.The total amount of soil erosion caused by cereal production reached to 8.72×10~8t in 2015,with an increase of 16%compared to2000.From the perspective of spatial distribution,the amount of soil erosion caused by cereal production in Northeast China was relatively high.Heilongjiang had the highest amount of soil erosion caused by cereal production,accounting for 15%of the national amount in 2015.According to the result,the national average amount of soil erosion caused by one unit of cereal production decreased to 1.52t/t in 2015.The amount of soil erosion caused by one unit of cereal production was higher in southwest and northeast of China.Yunnan had the highest amount of soil erosion caused by one unit of cereal production with4.72t/t in 2015.(2)With the expansion of provincial cereal trade,the total amount of embodied soil erosion transfer increased.The total amount of embodied soil erosion transferred in provincial cereal trade reached to 2.09×10~8t,with an increase of 118%,accounting for 24%of the total amount of national soil erosion caused by cereal production.The net cereal exporters such as Heilongjiang,Jilin and Inner Mongolia,usually took more responsibilities for soil erosion of cereal trade.And the net cereal importers mainly included Jiangsu,Guangdong,Sichuan,and Yunnan,were the major beneficiaries of cereal trade.Based on the perspective of the national soil erosion control,the amount of soil erosion caused by one unit of cereal production of the major net cereal exporters,such as Heilongjiang,Jilin,was higher than the national average.And the amount of soil erosion caused by one unit of cereal production of the major net cereal importers,such as Zhejiang,Jiangsu,was lower than the national average.This made the cereal trade pattern count against to the national soil erosion control.(3)The optimization analysis of cereal trade pattern showed that:based on the premise of constant amount of soil erosion caused by one unit of cereal production,the total amount of soil erosion decreased by changing the cereal trade pattern and production layout in China,with the national cereal production unchanged.From the demand side perspective,increasing cereal production in Jiangxi,Anhui and Jiangsu could reduce the soil erosion caused by cereal production with the decrease of 0.7%in China.Under the supply side optimization scenario,the soil erosion caused by cereal production in China could be reduced by controlling the cereal production scale in Heilongjiang,Jilin and Guizhou,with a decrease of 8%compared to 2015.