氮肥运筹对陆两优996吸氮、干物质生产和产量的影响

The Effects of Nitrogen Fertilizer Application on the Nitrogen Absorption,Dry Matter Accumulation and Yield of Super High-yielding Rice Luliangyou996

选用超级稻组合陆两优996,通过不同氮肥用量和不同基蘖肥与穗粒肥比例的处理,探讨陆两优996的物质生产和产量潜力及需氮特性。结果表明：陆两优996是一个需氮量较多、物质生产能力较强、产量高的组合,要获得7.5 t/hm^2以上的稻谷产量,地上部干物质生产达13 t/hm^2以上,稻谷收获指数0.53以上,产量结构为有效穗270万/hm^2以上,每穗粒数不少于120粒,结实率达90%以上。陆两优996的氮肥效益随施氮量的增加而下降,百千克稻谷产量的耗氮量随着施氮量的增加而上升;前期氮肥过量,影响后期氮素吸收积累。每公顷稻谷产量7.5 t以上总施氮量165～225 kg/hm^2,以施氮量195 kg/hm^2产量最高;基蘖肥用量115 kg/hm^2,约占总氮肥用量的60%～70%,总施氮量等于或低于165 kg/hm^2时,基蘖肥施氮量需占70%,如总施氮水平高于165 kg/hm^2,基蘖肥比例宜下调到60%,穗粒肥一般纯氮50～60 kg/hm^2为宜。

By the measures of different fertilization methods and different ratios of basal, tillering and panicle fertilizers, the characteristics of nitrogen absorption and its effects on the dry matter accumulation and yield of super high - yielding rice Luliangyou996 were discussed. The results show that Luliangyou996 is a high - yielding rice cross which needs much nitrogen fertilizer and has strong dry matter accumulation ability. In order to get high yield （ 〉7.5 t/hm^2）, high dry matter production（ 〉 13.0 t/hm^2） and high harvest index （ 〉 0.53 ）, yield components should be improved to achieve high efficient panicles （ 〉 270.0 × 10^4 panicles/ hm^2 ）, large number of grains per panicle （ no less than 120 grains） and high seed set （ above 90% ）. Along with the increase of nitrogen application, the benefit of nitrogen fertilizer of Luliangyou996 declines and the nitrogen amount for one hundred kilogram of grain rises. Over application of nitrogen fertilizer in the prophase, influences the nitrogenous absorbability and accumulation in the postphase. The total nitrogen demand is about 165 - 225 kg/hm^2 when the grain yield is more than 7.5 t/hm^2, but the grain yield is the highest when the ni- trogen application is 195 kg/hm^2. The proportion of basal and tillering fertilizer should be about 70% when the total nitrogen is less than 165 kg/hm^2 and it should decrease to 60% when the total nitrogen is more than 165 kg/hm^2. In general, 50- 60 kg/hm^2 nitrogen is appropriate for panicle fertilizer.