Soil organic carbon (SOC) is related to the sustainability of the agricultural systems affecting soil properties linked to crop yield. SOC affects the amount and availability of soil nutrients, contributing elements as N, usually deficient. In addition, SOC modify the acidity and the alkalinity towards values near the neutrality, and then it increases the solubility to several nutrients. SOC associated to the soil organic matter provides colloids having high cation exchange capacity. Its effect on the physical properties of the soil is reflected in the soil structure and pore size distribution. SOC concentration depends on the local environmental conditions, but it is also affected strongly by the soil management practices. There are managements that decrease SOC and viceverse other practices that favor the accumulation. The present review deals with the influence of SOC on the chemical, physical, biological properties of the soil and how it is affected by soil management. We also describes methodologies to study C0(2) fluxes from soil to atmosphere