Research On The Optimization Of Grain And Agricultural Planting Structure In Lindian County Based On The Perspective Of Combined Risk

Lindian county in Daqing city is not only a state-level poverty-stricken county,but also is a major grain-producing county in Daqing city.In the key period of planting structure adjustment and poverty alleviation,reducing the risk of cash return is conducive to maintaining the stability of grain growers’ income.In order to optimize the planting structure of the grain growers whose have different planting structures in Lindian county,the minimum risk value of the planting combination was taken as objective,which could provide reference suggestions for the government of Lindian county to guide the grain growers to adjust the planting structure from the perspective of reducing the risk.Based on investigated data,the actual return rate of single corn,"corn+red bean" portfolio,"corn+soybean" portfolio and "corn+soybean+red bean" portfolio were calculated.The expected return rate of corn and soybean was calculated according to the data of the “Compilation of National Agricultural Production Cost and Income”,and the expected return rate of red bean was calculated according to the investigated data.Using Markowitz mean-variance analysis method,the cash return risk value of single corn and the combination risk values of the above three crops were calculated with or without producer subsidy.According to Markowitz’s venture portfolio model,the planting structures of the three portfolios were optimized with or without producers’ subsidies by using linear programming method.The calculated results of risk values show that the risk value of the combined planting of the investigated growers were lower than that of the single corn growers whether to consider producers’ subsidies from government.When producers’ subsidies were not considered,the risk values were in the order of single corn,"corn+soybean" portfolio,"corn+soybean+red bean" portfolio,and "corn+red bean" portfolio.Respectively when considering producer subsidies,the growers’ risk values of single corn,"corn+red bean" portfolio,"corn+soybean+red bean" portfolio,"corn+soybean" portfolio,"corn+soybean" portfolio,and "corn+soybean" portfolio in order from high to low are listed.The results of planting structure optimization show that in "corn+soybean+red bean" portfolio,when subsidies are not considered,the planting proportion of corn was decreased after optimization,while that of soybean and red bean increases.When subsidies were considered,the planting proportion of corn and red bean decreases,while that of soybean was increased.In the "corn+red bean" portfolio,when subsidies are not considered,the planting proportion of corn was increased after optimization,while that of red bean was decreased.When subsidies are considered,the planting proportion of corn was increased,while that of red bean was decreased.In the "corn+soybean" portfolio,the effects of subsidies on the real return rate of corn and soybean showed synchronicity.Regardless of whether subsidies are considered or not,the planting proportion of corn was decreased after optimization and the planting proportion of soybean were increased.As the above optimization is only the overall optimization of the planting structure of the investigated villages,it is hoped that in the follow-up research,the planting structure can be optimized from the perspective of minimum risk according to the specific situation of each villages,so as to enhance the pertinency of the optimization.