Effects Of Nitrogen Density On Growth,Yield And Nitrogen Use Efficiency Of Japonica Rice

In recent years,many different types of Japonica rice varieties have been bred in Liaoning rice area,including high-yield varieties with erect panicle type,high-quality rice varieties with curved panicle type,and Hybrid Japonica Rice Varieties with strong resistance to barren soil.These varieties have their own characteristics in growth and development,yield and nitrogen use efficiency.Studying the response law of these varieties to different nitrogen application rates and transplanting densities can provide theoretical reference for nitrogen reduction and efficiency increase in production and formulate corresponding cultivation technical measures according to the characteristics of each variety.In this study,six different types of rice varieties were used as test materials.Three nitrogen fertilizer treatments and three density treatments were used to investigate the growth and development,yield and nitrogen use efficiency1.Nitrogen application rate had significant effects on growth and development,yield and nitrogen use efficiency of rice.When standard nitrogen was 60kg/667m~2,the tiller,dry matter accumulation,leaf area index and panicle traits of rice were the largest.The number of effective panicles per unit area of rice was the highest at the standard nitrogen level of60kg/667m~2,and the number of grains per panicle was 80 The yield reached the maximum at the standard nitrogen level of 60kg/667m~2,and the agronomic utilization efficiency and nitrogen absorption utilization efficiency of rice were the highest at the standard nitrogen level of 60kg/667m~2,and the nitrogen physiological utilization efficiency was the highest at the standard nitrogen level of 40kg/667m~2.2.Transplanting density also had a significant effect on the growth and development,yield and nitrogen use efficiency of rice.Leaf area index was the largest at the level of 30cm×16.5cm.The panicle length of rice was the longest at the level of 30cm×13.2cm.The effective panicle number and seed setting rate of rice were the highest at the level of 30cm×19.8cm.The yield was the highest at the level of 30cm×13.2cm.The agronomic utilization efficiency and nitrogen absorption utilization efficiency of nitrogen were the highest at the level of30cm×13.2cm,and the nitrogen physiological utilization rate was the highest at the level of30cm×19.8cm.3.Different types of rice varieties had different responses to nitrogen application rate and transplanting density.The yield of erect panicle conventional rice Beigeng 1705 and 1604reached the maximum at the standard nitrogen level of 80kg/667m~2,30cm×13.2cm,the nitrogen physiological utilization rate was the highest at the standard nitrogen level of40kg/667m~2,30cm×19.8cm,and the Nitrogen Agronomic utilization efficiency of standard nitrogen 80kg/667m~2,30cm×13.2cm.The yield of curved panicle conventional rice Shennong808 reached the maximum at the standard nitrogen level of 60kg/667m~2 and 30cm×19.8cm,the yield of Fengjin with curved panicle reached the maximum at the standard nitrogen level of 60kg/667m~2 and 30cm×13.2cm.The agronomic utilization rate of nitrogen was the highest at the standard nitrogen level of 60kg/667m~2 and 30cm×13.2cm,and the maximum nitrogen physiological utilization rate was at the standard nitrogen level of 40kg/667m~2 and 30cm×16.5cm.The yield of hybrid rice Liaoyou 9906 and Liaoyou 5206 was the highest at the standard nitrogen level of 60kg/667m~2,30cm×13.2cm,and the agronomic utilization rate and absorption utilization rate were the highest at the standard nitrogen level of 60kg/667m~2 and30cm×13.2cm.4.From the point of view of improving rice yield,when the nitrogen application rate reaches the standard nitrogen level of 60kg/667m~2,the effective panicles and grains per panicle of rice can be increased,and the yield of rice can be improved.The yield reaches the maximum when the transplanting density is 30 cm×13.2 cm.Increasing nitrogen use efficiency can reduce the cost of transplanting rice and reduce environmental pollution.When the nitrogen application rate reaches the standard nitrogen level of 60kg/667m~2,the Nitrogen Agronomic utilization rate and nitrogen absorption utilization rate of rice reach the maximum,and the Nitrogen Agronomic utilization efficiency and nitrogen absorption and utilization efficiency also reach the maximum when the transplanting density is 30 cm×13.2 cm.In this experiment,different varieties had different requirements for nitrogen fertilizer and transplanting density.The yield of erect panicle conventional japonica rice Beigeng 1705 and Beigeng 1604 was the highest at the standard nitrogen level of 80kg/667m~2 and 30cm×13.2cm,and the agronomic utilization efficiency of nitrogen was also the highest.The conventional japonica rice Shennong 808 and Fengjin with curved panicle were in the standard nitrogen level of 60.The yield of hybrid rice Liaoyou 9906 and Liaoyou 5206 was the highest at the standard nitrogen level of 60kg/667m~2,30cm×13.2cm,and the agronomic utilization rate and absorption utilization rate were the highest.