冬小麦一夏玉米一年二作制节水高产水肥耦合数学模型研究

Research on Mathematical Model of Water-Fertilizer Coupling for Water Saving and Higher Product of Double Cropping of Winter Wheat with Summer Corn

在人工控制试验条件下，采取二次通用旋转组合设计，系统研究了冬小麦一夏玉米一年二作制中上、下两茬作物的水肥耦合效应。结果表明，水肥耦合存在一个阈值。低于阈值下限水平，氮（N）、磷（P）无明显增产效应，水分利用效率低；高于阈值上限，水肥互作效应呈减小趋势；在阈值范围内，水肥互作增产效应明显。增加N、P投入和适宜限量供水是提高水利用效率的重要途径。通过对所建数学模型的计算机模拟，提出了不同决策目标下的水肥优化方案。

Under artificial control of test conditions, and adopting quadraric general rotational combination design, water-fertilizer coupling effects of double cropping of winter wheat with summer com are researched systematically. The reults showthat: the water-fertilizer coupling has a threshold; lower than the low-limit level of the threshold, the input of nitrogen andphosphorus has no obvious effect of increasing production, and has low water use efficiency; higher than the low-limit level ofthe threshold, the alternative input of water and fertilizer has obvious effect of increasing production. Increasing Input of nitro-gen-phosphorus and appropriately limiting water supply, are an important way for raising waer use efficiency. Through thecomputer simulation of the presented mathemaical model, an optimization scheme of water-fertilizer under different decision-objective is proposed.