Abstract:Soil carbon pool is very important for the sustainable development of agricultural systems and the change of soil carbon pool is mainly related to soil easily oxidized organic carbon(EOC). Results show that long-term application of manure and chemical fertilizers results in the reduction of the EOC content with decreased soil layer except no manure or chemical fertilizers. In group A (organic manure),the EOC content in ANP(organic manure +nitrogen,and phosphorus fertilizers) is the highest,followed by ANPK(organic manure+ nitrogen,phosphorus,and potassium chemical fertilizers) and ANK(organic manure+nitrogen,and potassium chemical fertilizers). The EOC content in AN0 (organic manure without nitrogen fertilizer) is the lowest. In B group(chemical fertilizer group),the EOC content in BNP(nitrogen and phosphorus chemical fertilizers) is the highest and then is the BNK(nitrogen and potassium fertilizers) and BNPK(nitrogen,phosphorus,and potassium chemical fertilizers). Compared with the no fertilization treatment,long-term fertilization can increase the EOC content in 0—60 cm soil layer and the application of organic manure,as well as organic manure and NPK chemical fertilizers,is better than the application of non-organic fertilizer.