Effects of Organic Soil Fertility Improving Material in Black Soil on Soil Productivity and Fertility

The 20-year field monitoring location experiments indicated that the treatment of integrated use of organic manure and chemical fertilizers can significantly increase the contents of soil organic matter,total N and P,available N,P and K.With the combined application of high quantities of organic manure and chemical fertilizer,organic matter N,P and K increased by 39.0% and total N by 30.7%.With respect to the contribution to land productivity,the long-term integrated use of organic manure and chemical fertilizers was superior to the mere application of chemical fertilizer.The productivity contribution of N fertilizer was 72.9% and that of the integrated application was 92.2%.Its contribution to yield-increase was 86.0%,1.8% higher than that under the N,P and K fertilizer treatment.The contributions of organic manure and no application treatment to land productivity were 80.3% and 39.6% respectively.The combination of high quantities of organic manure and N,P and K fertilizer was the highest as to productivity contribution,and could increase the nutrient contents of soil.It is the best fertilization structure of increasing productivity level and improving soil fertility.