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

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。

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

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.