水分-氮肥配合对油菜氮素利用效率的影响

采用盆栽试验方法,研究了不同水氮条件对油菜氮素利用效率的影响。结果表明:油菜氮素利用效率与氮肥用量、灌水控制水平关系极为密切,且水肥交互效应明显。油菜氮素利用效率随着氮肥用量的增加而显著降低;在施用氮肥的条件下,随灌水控制水平的提高而提高;在不施氮肥时适当提高灌水控制水平能提高油菜的氮素利用效率。水肥协调供应是油菜高产和提高氮素利用效率的重要措施。综合考虑,灌水水平控制在田间持水量的80%、施氮量为0.12g/kg(土)的组合是最优的。上述结果可为蔬菜的合理灌溉和施肥以及地下水环境保护提供理论依据。

Effect of Soil Water and Nitrogen Fertilizer Coupling on Nitrogen Efficiency of Rape

A pot culture experiment was conducted in greenhouse to investigate effect of soil water and nitrogen （N） on nitro- gen efficiency of rape. The results obtained were as follows ： The nitrogen efficiency of rape had close relation with soil water and nitrogen, and there was also a significant interaction between soil water and nitrogen. The nitrogen efficiency of rape sig- nificantly reduced with increasing of nitrogen rate, and increased with improving of water control level under nitrogen fertiliz- er condition. Improving water control level properly with no N fertilization could increase nitrogen efficiency of rape. The co- ordinating supply of soil water and nitrogen was important measures to get higher fresh weight and higher nitrogen efficiency.. Taking into accounts in all factors, the combination that soil water was Controlled 80% field capacity and nitrogen rate was kept 0.12g/kg was the best. The results obtained in this experiment could provide the theoretic base for reasonable irrigation and fertilization in vegetable cultivation and groundwater environment protection.