Effect of Different Amounts of N,P,K and Plant Density on Grain Yield and Quality of Rice

In order to increase grain yield and quality of rice,the experiments with the design for canonical analysis in investigating and simulating the effect of nitrogen,phosphorus and potassium application levels,seeding rate and transplanting density on the growth and development of rice plants were performed.The results indicated that grain yield and the N amount could be simulated in quadratic equation.Heavy dressing nitrogen caused the plants of two varieties late maturity,insufficient grain filling,low ripened grains and 1000-grain weight,and more chalky grains,besides low milling quality of Shendao 7.The suitable amount of N application for high-yielding plant population of Shendao 3 was higher than that of Shendao 7.The grain yield increased when the hill spacing was 10~15 cm for Shendao 3 companied with applying sufficient K and 15~20 cm for Shendao 7 companied with suitable amounts of N,P and K.Expanding hill spacing could reduce panicles per unit area but increase the spikelets per panicle.If the hill spacing was more than 20 cm,or the sowing rate was more than 80 g per plate,the milling quality would decrease.There were negative correlations between the panicles per unit area and spikelets per panicle,positive correlations between the brown rice rate and milled rice rate,brown rice rate and head rice rate,milled rice rate and head rice rate,and chalky grain and chalkiness.