Effect of cultivated factors on yield and quality of super rice in cold region

With quadratic general rotatory combination design,the experiments studied the influence of different amounts of N,K and plant density on yield and quality of super rice in cold region.The results indicated that the effect of nitrogen fertilizer effect on the yield was the most important role,followed by density and potassium fertilizer.At the same time,the experiments obtained the optimum planting program on the yield by frequency analysis.Nitrogen fertilizer could increase the protein,but showed a quadratic relationship with the head rice rate,the chalky grain and chalkiness.Potassium and nitrogen fertilizer showed a quadratic relationship with the amylose content.Gel consistency would be decreased when fertilizer and density added.The correlation analysis and path analysis indicated that there were negative correlations between protein and gel consistency,amylose content and gel consistency,the head rice rate and chalky grain,the head rice rate and chalkiness.Gel consistency for the direct and indirect functions on the taste scores was the most important factor of all.Therefore,the fertilizer and the density should be reduced to increase rice taste scores.