Effects of long-term organic manure application on crop yield and fertility of black soil

Based on long-term experiment located in central section of the northeast black soil,the effect of organic manure application on black soil fertility and crop yield was studied.The results show that long-term organic manure application could enhance black soil fertility,compared to pre-test,organic matter content,total nitrogen,total phosphorus,available nitrogen,available phosphorus and available potassium under organic manure application treatment demonstrated increase trend,organic matter content,total nitrogen,available nitrogen,total phosphorus,available phosphorus of fertilizer treatment showed increase trend, however,total potassium and available potassium showed opposite trend;under no fertilizer treatment,all indicators except total phosphorus and total potassium showed increase trend;C/N under different treatments demonstrated decrease,the range of values from 11.32 to 12.01;pH was suitable range for crop grow attributed to organic manure application.0.25 mm water stability aggregate under different treatments was in the order of fertilizer plus high organic manure(NPKM2) fertilizer plus low organic manure(NPKM1) fertilizer(NPK) no fertilizer(CK);the yield of maize and soybean indicated increase with fertilizer and organic manure application,and,annual yield of maize under different treatments showed increase trend,but,the same trend was not found in yield of soybean.The bio-exhausting experiment proved that organic manure application could increased black soil productivity.