通过两年在宁夏引黄灌区田间小区试验，以宁粳28号为材料，研究了3个不同灌水量与4个施氮水平对水稻产量、吸氮量及水氮利用效率的影响。结果表明，在相同灌水量条件下，两年水稻的籽粒和秸秆产量均随着施氮量的增加呈增加的趋势。不同灌水量对水稻产量影响不大，但施氮量却显著地影响着其产量和地上部吸氮量。灌水量或施氮量对水稻的株高、穗长、穗数和千粒重均无显著影响。05年和06年水稻氮肥利用率分别在5.1%~37.6%和14.1%~25.0%之间。相同施氮水平下，05年水稻氮肥生理利用率随着灌水量的增加而增加，06年水稻表现出相反的趋势。两年水稻的氮肥农学利用率在8.3~19.3 kg/kg之间。氮肥偏生产力在同一灌水水平下，都随着施氮量的增加而降低，在同一施氮水平下，灌水量处理间差异并不大。相同施氮水平下，水稻的灌水生产率随着灌水量的增加而降低。从产量、吸氮量及水氮利用效率等因素考虑，本试验水氮合理配比是灌水量控制在1.2×104 m3/hm2左右，施氮量240 kg N/hm2左右。

A field experiment was carried out with Ningjing 28 in direct irrigation zone by Yellow River in Ningxia from 05 to 06, to study the effects of 3 irrigation rate and 4 N rate on the yield, N uptake and water/N use efficiency of rice. The results indicated that both the grain yield and straw yield of two year rice was increased with N rate increasing under the same irrigation rate. N rate significantly influenced on the yield and N uptake of rice, but irrigation rate didn’t yet. Neither N rate or irrigation rate significantly influence on plant height, ear length, ear number per hectare and weight per 1000 seed of rice. Recovery efficiency of applied N of rice in 05 was ranged from 5.1% to 37.6%, that of in 06 was ranged from 14.1% to 25.0%. Under the same N rate, physiological efficiency of applied N of rice in 05 was increased with irrigation rate increasing, that of in 06 had the opposite tendency. Agronomy efficiency of applied N of two year rice was ranged from 8.3 to 19.3 kg/kg. Partial factor productivity from applied N of rice was decreased with N rate increasing under the same irrigation rate, but the difference among of treatments irrigation rate with the same N rate was not significant. Irrigated water use efficiency of rice was declined with irrigation rate increasing under the same N rate. Combination of the yield, N uptake and water/N use efficiency, the rational irrigation rate should be about 1.2×104 m3/hm2 and N rate about 240 kg/hm2 in the experiment.