Abstract: Based on a 17 years consecutive field trial,the paper explored the effects of different fertilization systems on crop yield and fertilizer contribution to give guidance for application of fertilizers.The results indicate that the application of N,P and K fertilizers can increase crop yiled by 32.10%,15.06%,10.95% respectively.The remarkable residual effect of recycled nutrients from farm manure on stabilizing and increasing crop yield is observed.In the case of optimum fertilization system of application of N,P and K fertilizers with recycled manure,the largest contribution rate of fertilization in the forming of crop yield can reach 0.44.It is concluded that application N,P and K fertilizers with recycled manure is an effective method to keep higher crop yield in low reach of Liaohe River plain.