Effects of Different Nitrogen,Phosphorus and Potassium Concentration on Production of Maize in Sanjiang Plain

In order to research the optimal fertilizer application in area of 853 Farm in Heilongjiang province,the field experiment of fertilizer effect was conducted using '3414' method.Quadratic equation of one variable and quadratic equation of three variables were studied.According to the quadratic equation of one variable,the most fertilization N-P2O5-K2O was 147.96,85.635 and 44.205 kg hm-2,and the most economical fertilization N-P2O5-K2O was76.245,52.98 and 32.4 kg hm-2.The three fertilizer must go together with each other,any one on the stress was not good for high yield.According to quadratic equation of three variables,the highest yield of 9 522.81 kg·hm-2would be reached when N-P2O5-K2O=131.7-85.3-36.1 kg·hm-2,The optimal fertilizer applied was N-P2O5-K2O=82.7-54.1-33.6 kg·hm-2 and yield was 9 288.54 kg·hm-2.