Organic matter is one of the main components of conservation production system. Soil organic matter is responsible for efficiently contributing to the physical, chemical and biological attributes of soils. Physical because SOM improves soil structure; chemical because it provides ions for the soil solution, besides contributing to the content of organic carbon and CEC (cation exchange capacity); and biological because it improves soil microbial activity. Soil organic matter is the largest terrestrial carbon reservoir, without considering fossil reserves. More than 58 % of SOM consists of organic carbon.