不同水氮供应对水稻产量、吸氮量及水氮利用效率的影响

以水稻节水和合理施用氮肥为目标,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,提出合理的水氮配置参数和管理技术,为宁夏引黄灌区水稻灌溉和施肥管理提供依据。通过2年在宁夏引黄灌区以水稻宁粳28号为材料,采用田间试验与室内分析的方法开展研究。试验结果表明,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。2005年和2006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,2005年水稻氮肥生理利用率随着灌水量的增加而增加,2006年水稻表现出相反的趋势。两年水稻的氮肥农学利用率在8.3～19.3kg/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,试验水氮合理配比是灌水量控制在1.2×104m3/hm2左右,施氮量240kg/hm2左右。

Effect of different water and N supply on the yield, N uptake and water/N use efficiency of rice

A field experiment was carried out with Ningjing 28 in direct irrigation zone by Yellow River in Ningxia from 2005 to 2006,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.Either 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 kg/kg 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 1.2×104m3/hm2and N rate about 240 kg/hm2in the experiment.