Effects Of Transplanting Density And Nitrogen Application Rate On Rice Yield And Nitrogen Use Efficiency

Rice(Oryza sativa L.)is one of the world's most important food crops and a staple food for nearly half of the world's population,playing an important role in global food production and security.This experiment was analyzed from the perspective of cultivation.In 2017-2018,Shihebei,Jidong County,Heilongjiang Province was used as a test site,and indica rice 12 and Longjing 21 were used as experimental materials.Three different transplanting densities and different densities were set through field plot experiments.The cultivation mode of nitrogen application rate was compared with the local conventional cultivation mode and b lank treatment to explore the relationship between suitable cultivation mode and rice yield and nitrogen use efficiency,in order to provide the necessary theoretical basis for local rice to achieve high yield.The results of this study are as follows:(1)Compared with the conventional cultivation mode(CK),the number of tillers of Japonica rice 12 and Longjing 21 increased significantly under the various treatments of increasing the transplanting density and reducing the nitrogen fertilizer cultivation m ode.This study believes that reasonable regulation of transplanting density can significantly increase the number of effective panicles per unit area,thereby increasing rice yield.(2)Compared with the conventional cultivation model(CK),the SPAD value s of indica rice 12 and Longjing 21 increased at the booting stage under the different treatments of increasing the transplanting density and reducing the nitrogen fertilizer cultivation mode,and there were significant differences among different varieties,but with The SPAD value increased significantly compared with no nitrogen application,indicating that nitrogen fertilizer can significantly increase the leaf color of rice.(3)Compared with the conventional cultivation mode(CK),increasing the transp lanting density and reducing the nitrogen fertilizer cultivation mode can significantly improve the leaf area index of the booting,filling and maturity stages of indica rice,so that it maintains a strong photosynthetic capacity;Increasing the transplanting density and reducing the nitrogen fertilizer cultivation mode can significantly improve the leaf area index of Longjing 21 during grain filling and maturity,so that it maintains a strong photosynthetic capacity.At the same time,the results also showed that the rice leaf area index decreased slightly compared with the conventional cultivation mode when the transplanting density was increased and the nitrogen fertilizer was too large.Therefore,increasing the transplanting density and reducing the amo unt of nitrogen fertilizer will help to increase the leaf area index of rice during the reproductive growth stage.(4)Compared with the conventional cultivation model(CK),the increase of the amount of dry matter accumulated in the aboveground part of rice under the application of nitrogen fertilizer decreased slightly,and the results of the study on the dry matter accumulation of various organs in different periods of rice showed that the rice was The dry matter accumulation of leaves and stems and sheaths increased first and then decreased with the growth process,and the dry matter accumulation of the ears increased continuously.However,increasing the transplanting density and reducing the nitrogen fertilizer can maintain the dry matter quality of th e leaves and increase the dry matter accumulation of the rice ears by regulating the accumulation of dry matter in different organs.(5)Compared with the conventional cultivation model(CK),the yield of Japonica rice 12 increased significantly under the increase of T2 and the application of nitrogen fertilizer;the yield of Longjing 21 increased significantly under the increase of T1 and the application of nitrogen fertilizer.This study believes that the main factor to increase the density of transplante d rice and increase the yield of nitrogen fertilizer is the increase in the number of effective panicles.The limiting factor of increasing the density and reducing the nitrogen fertilizer production is no longer sustained.The limiting factors are the seed setting rate and the number of kernels per panicle.(6)Compared with conventional cultivation mode(CK),increasing the transplanting density and reducing nitrogen fertilizer can significantly improve the nitrogen use efficiency of rice.Combined with the yield data,it can be said that increasing the transplanting density and reducing the amount of nitrogen fertilizer can increase production and increase efficiency,and achieve high yield and high efficiency.Coordination and unity.