Abstract:

【Objective】 Effect of reducing chemical nitrogen fertilizer and increasing organic manure on soil organic carbon content and carbon pool management index (CPMI) were examined, and the best design of organic manure and chemical fertilization proportion was researched. 【Method】 Take typical black soil from Shuangcheng in Heilongjiang as an object, the five treatments: only chemical fertilizer, application of 5/6(N) +1/6 organic manure, application of 4/6(N)+2/6 organic manure, application of 3/6(N) +3/6 organic manure, application of 2/6(N) +4/6 organic manure were designed, choosing classical method for measuring organic carbon and active organic carbon content, and carbon pool management indexes were measured. 【Result】 The organic carbon content and active organic carbon content in the treatment of application 2/6(N) +4/6 organic manure and the treatment of application of 3/6(N) +3/6 organic manure was higher than the treatment of application of only chemical fertilizer by 15.7%, 6.4% and 8.2%, 10.9% respectively ; application of 3/6(N) +3/6 organic manure and application 5/6(N) +1/6 organic manure had the highest CPMI value, and the average value was both both higher than application of 2/6(N) +4/6 organic manure, application of only chemical fertilizer by 13.0%; the average grain yield of application only chemical fertilizer, application 5/6(N) +1/6 organic manure, application of 3/6(N) +3/6 organic manure was higher than the other treatment by 9.1%. 【Conclusion】 The different proportions of organic manure and chemical fertilizer has a significant influence on organic carbon, active organic carbon, CPMI and grain yield, application of 3/6(N) +3/6 organic manure can increase organic carbon, active organic carbon, CPMI and grain yield significantly, so it is the best proportion of organic manure and chemical fertilizer in Shuangcheng.

Key words: CPMI')">CPMI, soil organic carbon, active organic carbon, organic fertilization measurement