氮肥运筹对机械穴直播早稻产量的影响

选用常规稻品种中嘉早17和杂交稻品种株两优189,利用2BX-10水稻精量穴直播机,研究氮肥运筹对机械直播早稻产量的影响。结果表明:在施氮总量为165 kg/hm2的相同条件下,穗肥用量为总量的20%时比30%的产量显著下降;穗肥为总量的30%,苗、蘖肥用量的变化对产量影响差异不显著。增加苗肥用量促进分蘖;苗肥用量达40%时,分蘖高峰值最大,无效分蘖大量发生,成穗率显著下降。最高茎蘖数与苗肥施用量显著正相关。中嘉早17的有效穗因苗肥和分蘖肥的不同用量影响差异很小。株两优819有效穗数则随着苗肥用量的增加有效穗增加,但成穗率下降。株两优819叶面积指数高于中嘉早17,叶面积指数达高峰后,中嘉早17下降量少,株两优819叶面积指叶面积指数下降很快。增施苗、蘖肥对干物质总积累量影响的差异不大,但是重施苗肥、不施分蘖肥、少施穗肥的处理,其干物质总积累量显著减少。苗、蘖肥占总用量30%时,苗、蘖肥用量的变化对产量影响差异不显著。机械穴直播早稻合理的氮肥运筹方式以m(基肥)∶m(苗蘖肥)∶m(穗肥)=4∶3∶3为好。

Effects of Nitrogen Application on Grain Yield of Mechanical Direct-hole-seeded Early Rice

Inbred rice variety Zhongjiazao17 and hybrid rice variety Zhuliangyou 819 was planted to study on effect of application of nitrogen on grain yield of machinical direct?seeded early rice through 2BX?10 type of direct seeding machine.The result showed that at the rate of nitrogen application of 165 kg/hm2,when the rate of panicle initiation fertilizer was 20% of the total N,the grain yield was decreased significantly,however,wea?ning and tillering fertilizer application had no significant effects on yield applied 30%at initiation panicle of to?tal.Increasing the rate of weaning fertilizer application promoted tillering.When 40% at weaning fertilizer was applied for total N rate,it could lead to appear the maximum value of tiller at the peak,occurre large number of ineffective tillers and decline significantly the productive tillers.The maximum number of tillers was positively correlated with weaning fertilizer application.The difference on effective panicle was little due to the N amounts of weaning and tillering fertilizer in Zhongjiazao17.The effective panicle was increased and rate of effective pani?cle was decline with the increased amount of weaning fertilizer in Zhuliangyou819. Rate of weaning and tillering fertilizer application had no significant effect on yield. The leaf area index of Zhuliangyou 819 was higher than leaf area index of the Zhongjiazao17.Leaf area index of Zhongjiazao 17 decline less and leaf area index Zhulian?gyou 819 the decline very fast after the peak of leaf area index reached.The difference of seedling,tiller fertilizer on dry matter accumulation has little effect,but again,the total dry matter accumulation was significantly reduced that the treatment for applied heavy seedling fertilizer,no applied tiller fertilizer and applied few panicle fertiliz?er.The reasonable nitrogen application was split?applied:40%at base fertilizer,30%at weaning and tillering fer?tilizer,and 30% at panicle fertilizer of mechanical direct?hole?seeded early rice.