根系分区交替滴灌下水氮耦合对棉花氮素利用效率的影响

该文采用施氮量（N90、N180、N270）和灌水量（W140、W200、W260）3水平完全组合设计，研究水氮耦合对根系分区交替滴灌棉花氮素吸收和利用影响。结果表明：在根系分区交替滴灌下棉花干物质量和氮素含量随灌水量增加而显著提高，其中中氮高水耦合（N180 W260）是获取较高干物质量和氮素含量最为有效处理。从提高产量、氮素吸收和利用角度分析，比较产量相对较高的中氮高水（N180 W260）、高氮中水（N270 W200）和高氮高水（N270 W260）处理，N180 W260的氮肥吸收比例、N回收率、氮肥农学利用效率和表观利用效率最高，氮肥生理利用效率无显著差异。因此N180 W260是氮肥吸收和利用效率较高的水氮耦合处理，其显著提高棉花干物质量及氮素吸收性能，对于棉花水肥管理具有实际意义。

Effects of water and nitrogen coupling on cotton nitrogen absorption and utilization under alternate root partition drip

In this study, nitrogen application (N90, N180, N270) and irrigation (W140, W200, W260) was completely modular designed for studying the coupling effects of water and nitrogen on cotton nitrogen absorption and utilization under alternate root partition drip. Amount of dry matter and nitrogen content of cotton with increased irrigation were markedly improved, medium nitrogen and high water coupling (N180, W260) was the best treatment for high dry matter amount and nitrogen content. From the perspective of improving yield, nitrogen uptake and utilization analysis, the results of medium nitrogen and high water (N180W260), high nitrogen and medium water (N270W200), high nitrogen and high water (N270W260) treatments were compared, which showed that nitrogen derived from fertilizer (Ndff), nitrogen recovery, apparent N-fertilizer recovery efficiency(ANRE), agronomic efficiency of applied N-fertilizer ( AENF) in N180W260 treatment is higher than that in the other treatments. There is no significant difference in physiological N-fertilizer use efficiency (PNUE) in all the treatments. Medium nitrogen and high water (N180W260) was the best coupling of water and nitrogen, which provided a reference for water and fertilizer management in cotton.