滴灌水肥耦合对农田水氮利用的影响

Coupling Effects of Water-fertilizer on Utilizing of Moisture and Fertilizer under Drip Irrigation

为了寻求适宜华北地区的滴灌优化水肥耦合制度,针对华北地区冬小麦,以Φ20cm蒸发皿的水面蒸发量(E)为参考,通过大田试验,研究了大田滴灌水肥耦合模式对土层储水量、储氮量及水分利用效率的影响。结果表明,土壤水分的变化和冬小麦产量受灌溉定额的影响更为明显;由于水肥耦合的效应,高施氮量未必产生较大的硝态氮累积,适宜的灌水定额和施肥量配比能够促进产量的累积和提高水分利用效率;试验组合中,在灌水定额0.8 E、施肥量为190kg/hm^2的水肥耦合模式下,产量和WUE最高,硝态氮淋失潜在风险相对较小。

For the purpose of finding an optimized water-fertilizer coupling regime in North China,a field experiment was conducted to study the coupling effects of water-fertilizer on soil water storage,soil nitrogen storage and water use efficiency under drip irrigation,with winter wheat as test crops,following the evaporation of 20 cm pan on the crop canopy.The results indicated that variations of soil water content and yield of winter wheat were mainly affected by irrigation scheduling.In addition,high fertilizer might not produce more nitrogen accumulation in farmland because of the coupling effect of water and fertilizer.Proper ratio of irrigation quota and fertilizer could produce more yield and increase water use efficiency at the same time.In this experimental combination,the yield of winter wheat and water use efficiency reached the maximum level under the coupling combination that irrigation quota was 0.8 Eand the amount of fertilizer was 190kg/hm^2,with lower nitrate leaching potential risksimultaneously.