Effects of K Fertilizer Application Amount on Yield and Qualities of Rice in Cold Region

Kongyu131(Japonica) was used as material to analyze the effects of K fertilizer application amount on yield components and quality characters,and provide evidence for rational fertilization of high quality rice production in cool regions.The results showed that,the application of K fertilizer greatly increased effective panicles,grains per panicle,grain yield and head rice rate;decreased the chalky rice rate and amylose content in endosperm,but had a little influence on seed setting rate,1000-grains weight,brown rice rate,chalkiness area and chalkiness degree;the application of K fertilizer also increased the total nitrogen content,protein nitrogen content and the protein nitrogen ratio in endosperm,thus improved the nutrient quality.On the other hand,K fertilizer application decreased the gelatinization temperature,final viscosity,consistency and setback,increased the peak viscosity,hot viscosity and breakdown values,with the greatest impact on setback value.To a certain extent,the amount of K fertilizer application had obviously and positively impact on the yield components,quality index and characters of starch viscosity profile,then the its impact became weaker out of certain levels.The optimal K fertilizer application amount in this experiment condition is 90.0 kg hm-2 K2O.