重施穗肥对杂交水稻的产量和氮素营养的影响

EFFECTS OF HEAVY SPIKE FERTILIZER ON YIELD AND NITROGEN NUTRITION IN MIDDLE-SEASON HYBRID RICE

对水稻不同品种(组合)进行了连续8年的施肥技术的研究,结果如下:重施穗肥与常规施肥比较,大穗型品种之间的产量差异显著,其中杂交稻增产的幅度(10%～21.5%)较常规稻品种大,但穗数型品种之间的产量差异不显著。重施穗肥可降低无效分蘖率,增加成穗率,提高单位面积上总颖花数和实粒数。抽穗至灌浆期间,重施穗肥较常规施肥叶面积指数(LAI),平均增加1.2,叶片含N率提高11%～15%,光合速率增高7%左右,干物质生产量增长14.4%。稻株对穗肥中N的吸收利用率较基肥和分集肥中N分别高出22.3%和14.6%,而且穗肥中N向穗部的转运率较基肥和分蘖肥中N分别提高9.2%和11.0%。

The physiological basis of fertilizer techniques and efficiency on different rice varieties (combinations) were investigated in a period of eight years. This results were as follows: 1) Compared with conventional fertilizer, heavy spike fertilizer mainly brought about yield difference among large-panicle types, with the middle-season hybrid rice gaining more than the conventional rice varieties in yield. But the yield difference was not obvious in the quantity-panicle type. 2) By placing emphasis on heavy spike fertilizer, the yield of hybrid rice increased by 10～21.5 percent as compared with that of conventional fertilizer. 3) The ineffective tillering ratio of hybrid rice was decreased by heavy spike fertilizer as compared with that of a conventional fertilizer. But the ripened spike ratio, total spikelets and ripened grains per mu were increased. 4) The sizes of LAI increased by 1.2 and the percentage of leaf N content increased by 11～15 percent and the photosynthetic efficiency increased by about 7.0 percent and the dry weight increased by 14.4 percent around the period of heading stages and the milk ripe stages. 5) The uptake ratio of spike fertilizer-N increased by 22.3% and 14.6% as compared with that of the basis fertilizer-N and tillering fertilizer-N. Also the transport ratio of spike fertilizer-N into the spike increased by 9.2% and 11.0%.