Effects of Organic Manure and Fertilizers Long-Term Located Application on Soil Fertility and Crop Yield

【Objective】 To evaluate the effect of organic manure and fertilizers long-term located application on soil nutrients and crop yield.【Method】 The results of crop yields and soil nutrients were measured and collected based on a 22-year long-term located application of organic manure and fertilizers experiment in Yucheng city of Shandong Province.【Result】 The effect of chemical fertilizers on winter wheat yield was better than organic manure during the first 8-10 years,but the reverse result was observed in summer maize yield.The combined effect of chemical fertilizers with organic manure on wheat and maize yields was very obvious.However,with prolonged application,the yields of each treatment,no matter with organic manure or chemical fertilizer or combined,turned out similar.Soil organic matter content increased with time and application level of organic manure during the 22 years.Soil organic matter and total nitrogen contents were found unrelated to the application rate of chemical fertilizers in this long-term experiment.Increased application of chemical fertilizer could enhance soil available nutrient contents and at the same time be kept relatively stable to some extent.【Conclusion】 The effect of chemical fertilizer on winter wheat yield was better than organic manure during the first 10 years,however,a reverse result was observed in summer maize yield,and after that the crop yields of all treatments were found similar.Therefore,increased application of fertilizer did not improve the crop yield.The effect of organic manure on soil organic C and N content increase was much better than chemical fertilizer,and the soil organic C and N content increased with the application rate of organic manure.Soil organic C and N content could not be improved by application increase of chemical fertilizer.With prolonged application,organic manure could improve soil available nutrients content continually,and its effect was found much obvious than that of chemical fertilizer.