应用动态-线性规划确定作物多熟种植最佳方案的研究

本文采用动态规划与线性规划相结合的方法研究作物种植方案的优化。用这种方法可同时解决四个问题,即种植作物的种类、面积比例、空间配置和最佳肥料分配方案。在线性规划中,把经济效益做为目标函数,生态效益做为约束条件,可解决经济效益和生态效益的矛盾。线性规划约束条件中的产量等参数和目标函数中的系数C用动态规划求得,动态规划的y_k(X_k)通过线性规划和投氮效益表求得。动态规划方程的解是线性规划方程的起点,线性规划方程的解反过来也是动态规划方程的起点。对二个方程反复求解,最终可得到稳定最优解。在动态-线性规划方法下,目标函数中的系数C和约束条件中的参数在达到稳定最优解前都是不断变动的,这样就使规划结果比单纯用线性规划方法得到的结果更合理,更接近实际,更能反映生产条件的变化对作物种植方案的影响。研究结果表明,采用动态-线性规划方法研究作物种植方案的优化是可行的。

OPTIMIZING CROP DISPOSITION PLAN IN MULTIPLE CROPPING SYSTEMS USING LINEAR-DYNAMIC PROGRAMMING

A combination of dynamic and linear programming has been applied to optimize crop disposition plan in multiple cropping systems. Four problems of cropping disposition could be simultaneously solved: kinds of crops; proportion of acreages; spatial disposition and best distribution of fertilizers. In linear programming the economic effect was taken as objective function while ecological effect as constraints so that the possible contradictions could be reduced. The parameters such as the yields of crops and coefficient of objective function were obtained from dynamic programming while yk(xk) of dynamic equations calculated from linear equations and fertilization efficiency tables. A stable optimum solution of the system was obtained through repeated forming and solving the dynamic and linear equations. Using this method the results of programming were more reasonable and the variation of production conditions could be better reflected.