The study looked at how using mineral fertilizer and organic manure affects different types of organic carbon in soil. They found that adding both types of fertilizer increased the overall organic carbon in the soil. The combination of inorganic fertilizer and organic manure had the highest levels of dissolved and microbial organic carbon. However, long-term use of inorganic fertilizer alone decreased the amount of particulate organic carbon in the soil. Organic manure was shown to significantly increase the concentration of organic carbon in the soil.