作物非充分灌溉制度的模拟优化方法

非充分灌溉条件下作物灌溉制度优化可以有效地提高作物产量及水分利用率。以农田水量平衡模拟模型、作物水分生产函数和水分敏感指数累积函数为基础,建立了以灌溉日期为决策变量的非充分灌溉制度模拟优化模型,利用单纯形搜索法来确定最优灌溉制度(以作物产量最高为目标)。针对北京1999年冬小麦返青后的实际情况,利用以上方法对冬小麦灌溉制度进行了模拟与分析。结果表明,随着灌溉定额的增加,最优灌溉制度下的田间腾发量和冬小麦产量也相应增加,但其增加幅度却逐渐减小。在灌溉水量不足的条件下,应首先保证抽穗初期的灌溉,然后考虑在拔节期进行灌溉,可以达到较好的增产效果。

Simulation-optimization method for crop irrigation scheduling with limited water supplies

Optimal irrigation scheduling with limited water supplies can increase crop yield and water use efficiency. A simulation-optimization model was developed for crop irrigation scheduling with the irrigation date as the decision variable. The model was based on a simulation model of the soil water balance and the crop water-production function, and was optimized using the simplex evolutionary method. The model was used to optimize the irrigation scheduling for winter wheat after greening in Beijing with the 1999 meteorology history. The simulation results show that both field evapotranspiration and crop yield increase with the irrigation quota, but with decreasing slopes. Irrigation in the early heading stage is the most efficient, with irrigation in the shooting stage also recommended for larger irrigation quotas.