Effections of soil organic carbon and soil inorganic carbon under long-term fertilization

Under the application of different fertilizers condition,changes of SOC and SIC in 0～50 cm layer were studied in a long-term fertilizer location experiment that had been conducted for 18 years.The results indicatesd that the impact on organic carbon of soil drops with increase of the depth of soil layer to apply fertilizer,the organic carbons of soil of 0～7.5 cm soil layer were separately 4.6%,22.0%,63.1% higher than 7.5～15 cm,15～30 cm,30～50 cm.The inorganic carbon drops with the increasing of organic carbon in the soil.Contrary to change law of the organic carbon.Different types of fertilizer were not the same in change of the organic carbon of soil.The long-term application of chemical fertilizers and manure and applied manure fertilizer could increase soil organic carbon in 0～30 cm layer,reduce the content of inorganic carbon.But there had been no obvious difference between soil organic carbon and soil inorganic carbon for the long-term application of chemical fertilizer.