关于不同籼稻品种和施肥时期稻株对15N的吸收及其分配的研究

氮肥吸收率随不同水稻品种产量水平的提高而提高。稻株对氮肥的吸收率在分蘖期各品种之间差异不显著，而在灌浆成熟期表现其显著差异，即矮秆水稻品种和杂交稻对氮肥的吸收利用率高于高秆水稻品种。杂交稻汕优63，稻株对穗肥15N的吸收收率明显高于基肥15N和分蘖肥15N。杂交稻汕优63在抽穗后20天，有50%或50%以上被吸收的15N转

Studies on Rice Uptake and Distribution of (15)~N Fertilizer in Different Varieties of Indica Rice and at Different Growth Stages

The experimental results are as follows:1. The uptake ratio of l5N fertilizer increases with the increase inthe yields of different rice varieties. The differences in the uptake ratios of 15N fertilizer of rice are not distinct from one variety to another at the stage of tillering, but the differences are very obvious at the stage of milk ripening or yellow ripening. The uptake ratio of 15N fertilizer of short-stalked rice and hybrid rice is higher than that of tall-stalked rice.2. As for the hybrid rice-Shan You 63,the uptake ratio of 15N panicle fertilizer is evidently higher than that of 15N basal-dressing fertilizer and 15N tillering-dressing fertilizer.3. In the hybrid rice-Shan you 63,50% or more of the l5N fertilizer was transported to the panicles 20 days after heading. The content of 15N fertilizer was different in different dressing periods. The content of panicle fertilizer was significantly higher than that of basal-dressing fertilizer and tillering-dressing fertilizer