Effects of Nitrogen Application on Grain Yield of Mechanical Direct-hole-seeded Early Rice
TAN Xue-ming;JIA Wei-qiang;LI Mu-ying;ZEN Yan-hua;SHI Qing-hua;PAN Xiao-hua;Key Laboratory of Crop Physiology,Ecology and Genetic Breeding,Ministry of Education/Jiangxi Key Laboratory of Crop Physiology,Ecology and Genetic Breeding/Collaborative Innovation Center for the Modernization Production of Double Cropping Rice,Jiangxi Agricultural University;
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,weaning and tillering fertilizer application had no significant effects on yield applied 30% at initiation panicle of total.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 panicle 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 Zhuliangyou 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 fertilizer.The reasonable nitrogen application was split-applied: 40% at base fertilizer,30% at weaning and tillering fertilizer,and 30% at panicle fertilizer of mechanical direct-hole-seeded early rice.