The optimum NPK proportion,applied rate and its effects on yield components for large spike wheat variety have been studied by regression analysis of three factors in the condition of high level water and fertilizer.The results indicate that the effect order on yield from high to low is phosphorus,nitrogen,potassium.The optimum applied rate is N 17751877kg/6667m2,P2O5 9261110kg/6667m2,K2O 14141447kg/6667m2,with the proportion of NPK 1056078.In addition, the fertilizer applied rate affects the yield componen...