Abstract:This paper deals with the contribution of fertilizers to yield and the effect of different fertilization system on rice yield through a ten-year field experiment. Results indicated that fertilization system greatly affected rice yield. The general trend was MNPK>NPK>MNP, MN>NP; M,N>CK. Using chemical fertilizer was a major measure for higher output and its contribution accounted for 70% of all the output increased, and other 30% attributed to organic fertilizer. Yield increase from organic fertilizer was mostly attributed to K (80%) carried by organic material. About 44% of yield increase was attributed to N applied, mainly inorganic form. Potassium fertilization contributed to 50% of yield increase, with similar effect from organic and inorganic sources. So the use of organic fertilizer in combination with chemical one might fulfil 90% requirement for higher output. Effect of P fertilizer was rather poor, even it might cause a decrease in yield owing to the stress of some microelement which may be induced by overuse of P fertilizer. Long-term application of chemical fertilizer had little effect on soil organic matter content, but signiticantly increased output of grains. However when organic fertilizer was used with chemical one, not only a good output might be attained, but an increase in soil organic matter might become possible so as to establish a better foundation for further more output.