Effects Of Transplanting Density And Nitrogen Application On The Yield And Some Physiology Properties In Early Rice

To clarify the effects of different nitrogen application and transplanting density on grain yield and some physiology properties in early rice,the field experiment with super hybrid rice luliangyou996 and inbreed rice zhongzao22 were conducted,separated by cultivars,by using split plot design with three replications in Changsha(two varieties),changde(zhongzao22),chenzhou(luliangyou996) in 2007. Nitrogen fertilizer rates(0,105,150,195 kg/hm~2,named as N1,N2,N3,N4 ) were taken as the main plots and different transplanting densities(36×10~4,30×10~4.24×10~4 holes/ hm~2,named as D1,D2,D3) were taken as the subplots.The measurement concluded expansion of leaf area,yield,yield components,accumulation of dry matter, NPK content,the shape of upper three leaf,oxidation ability of root and other physiological properties.The key results are as follows:1.The application of nitrogen fertilizer had a significant effect to improve the incidence of rice tillers.With the increase in the application of nitrogen fertilizer,the number of tillers per plant stems increase faster.The greater the application of nitrogen fertilizer,the more conducive to rice tillers.With the increase in the transplanting density,the total numbers of tillers were more in the unit area,and always maintain this result.The increases of leaf area index(LAI) go with the progress of reproductive age.There was significant difference in the highest leaf area index among all nitrogen fertilizer application.The leaf area index differences were not significant under different transplanting density levels.The interaction effects about leaf area index between nitrogen application and transplanting density obviously.Reduce the application of nitrogen and(or) transplanting density can reduce the leaf area index.2.The application of nitrogen fertilizer had a significant effect on the growth and development of rice,dealing with different nitrogen fertilize had a significant difference on the yield,effective panicles,grain per panicle,harvest index.The zhongzao22 experiment results showed that during 0-195kg/hm~2(pure nitrogen),the relation of N amount to grain yield was expressed in a single peak curve with the peak(changsha:7.5t/hm~2,changde:9.4 t/hm~2) of grain yield at 150 kg/hm~2 of pure nitrogen and with the most apparent yield-increasing effect between 0 and 150kg/hm~2 of pure nitrogen.The luliangyou996 experiment results showed that during 0-195kg/hm~2(pure nitrogen),With the increase in the application of nitrogen fertilizer, the yield of Lu Liangyou996 increase faster.When nitrogen rate increased to 195 kg/hm~2 with the highest yield.Influences of different transplanting densities on effective panicles,grain per panicle and plant height were higher than that on seed setting rate and 1000-grain weight.There was no significant difference in yield among treatments with transplanting densities ranging from 30×10~4 to 36×10~4 holes / hm~2.Under the experimental conditions,there was no interaction between nitrogen application and transplanting density on the yield.3.Different application of nitrogen fertilizer had a significant effect on the oxidation ability of root,with the increase in the application of nitrogen fertilizer;the oxidation ability of root with had an increasing trend.In the period of panicle initiation stage,the oxidation ability of root has the highest numbers.Dealing with different transplanting density had no significant difference on the oxidation ability of root.With the increase in the application of nitrogen fertilizer and the decrease of transplanting density,all of the length and angle of leaves had an increasing trend.4.With the increase in the application of nitrogen fertilizer and the transplanting density,the production of dry matter had an increasing trend and a significant effect. In maturity,there was a high degree of correlation between dry matter production and yield.5.The N,P content percentage of Rice Plant was increased with the improvement of application of nitrogen fertilize,The K content percentage of Rice Plant was decreased with the improvement of application of nitrogen fertilize.But excessive N content percentage and nitrogen accumulation were not of benefit to the transfer of nitrogen from vegetative organs(leaf,sheath and stem) to panicle,resulting in the reduction of N-accumulation amount in seeds,seed setting rate,1000-grain weight and yield.The N,P,K content percentage was of the maximum in mid-tillering stage, different application of nitrogen fertilizer had a significant effect to N,P,K content percentage,different transplanting density had little effect to N,P,K content percentage.6.Under medium-fertility field,the better N accumulation of stem,sheath and leaf before heading,the better N transfer from stem,sheath and leaf to panicle after heading,the better coordinate relationship among panicle number,seed setting rate and 1000-grain weight and higher yield would be obtained with nitrogen application of 150kg/hm~2 and transplanting density of 30×10~4 holes/hm~2.