杂交水稻氮肥施用技术研究

Research on the Application of Nitrogen Fertilizer in Hybrid Rice

通过不同氮肥施用法对杂交水稻群体、穗粒结构及产量的效应分析，表明重前施肥法能获得较多 的有效穗，但每穗粒数较少、粒重软低．适当降低前期用肥量，增加保花肥、粒肥的施用，可提高成穗率，增加千 粒重，从而提高产量．

The results of the nitrogen fertilizer （urea） applying research conducted with Shanyou 48-2 in the early cropping season and Xieyou 46 in the late cropping season of 1991 as the materials showed that the conventional applying method with most N fertilizers in the early growth stage （as basic and tillering） might get more productive panicles but fewer spikelets per panicle and lighter grain weight. Properly decreasing the proportion of N fertilizers used at the early growth stage and increasing the proportion of N fertilizers at the late growth stage （as spikelet developing and grain filling） could increase the panicle-bearing tiller rate by 1.44 %-8. 12% ,seed set by 1.61-7. 52 % and 1000-grain weight by 0. 09-0. 81g. Of the treatments, the applying method of N fertilizer with 70% as hasic, 20% as spilkelet developing and 10% as grain filling obtained the highest yield, 7.61-7.81% higher than the control.