稻-麦轮作条件下2种施肥模式作物产量和农田氮磷径流流失比较

稻-麦轮作是太湖流域典型的集约化粮食作物种植体系,化肥用量大,氮磷流失控制广为关注。采用大区田间对比试验,研究了习惯施肥(FP)和优化控制施肥(CM)2种施肥模式对作物产量及氮磷肥料偏生产力的影响,同时探讨了2种施肥模式下农田径流水中各形态氮、磷的特征和径流氮、磷损失的差异。结果表明:优化控制施肥水稻和小麦地上部总生物量、籽粒产量、植株地上各部位养分(氮磷钾)含量及积累量与习惯施肥差异不显著(P>0.05);优化控制施肥水稻和小麦的氮肥偏生产力显著大于习惯施肥(P<0.05),磷肥偏生产力也相似。稻季和麦季优化控制施肥径流水中各形态氮、磷浓度小于习惯施肥,甚至达到显著水平(P<0.05);稻季、麦季和完整轮作期优化控制施肥总氮、总磷的累积流失量显著小于习惯施肥(P<0.05)。优化控制施肥模式不仅能保持水稻和小麦的籽粒产量,而且能显著减少稻-麦轮作体系的氮磷流失,可以在实际农业生产中加以推广和利用。

Comparative of Two Fertilization Modes on Crop Yields and Nitrogen/Phosphorus Runoff Losses Under Rice-wheat Rotation

Rice-wheat rotation is a typical intensive cropping system for food production with application of huge amounts of chemical fertilizers in the Tai Lake Basin and the control of nitrogen and phosphorus runoff losses is widely concerned. In this paper, the effects of two different fertilization modes including farmer practice (FP) and optimized control fertilization (CM)on crop yield and partial productivity of nitrogen and phosphorus fertilizers were investigated with a large-area field comparison experiment. Meanwhile, the characteristics of nitrogen and phosphorus forms in runoff water and the differences of nitrogen and phosphorus runoff losses were explored.The results showed that rice or wheat above-ground total biomass, grain yield, nutrient (nitrogen, phosphorus and potassium) contents and accumulation in plant ground parts of CM mode were not significantly (P>0.05) different from those of FP mode. The rice or wheat grain partial productivity of nitrogen fertilizer of CM mode was significantly (P<0.05) greater than that of FP mode, the same results was found for phosphate fertilizer. The concentrations of all nitrogen and phosphorus forms in runoff water of CM mode during rice and wheat growth seasons were lower than those of FP mode, even significantly (P<0.05). In the rice or wheat growth season and the whole rotation period, the cumulative losses of total nitrogen or total phosphorus of CM mode were significantly (P<0.05) less than that of FP mode. Optimized control fertilization mode could not only maintain the grain yield of rice and wheat, but also significantly reduce the runoff losses of nitrogen and phosphorus in the rice-wheat rotation system, which could be promoted and utilized in actual agricultural production.