Soil carbon stock in silvopastoral system, pasture and sugarcaneculture

Abstract

The conversion of natural system in tillage agriculture areas is largely responsible for the reduction of Organic Carbon stock (OCstock) in the soil and increases C-CO2 atmospheric release in tropical countries. The objective of this study was to evaluate the impacts of different situations of soil uses (silvopastoral, pasture and sugarcane) in OC-stocks of Utilsols in the regions of Vale do Rio Doce in the state of Minas Gerais. It was determined contents of total soil organic carbon (SOC) and soil bulk density (Bd) in different situations studied. The use of anthropic soil is promoting the increase of the soil Bd due to the deployment of cultures being preformed mechanically, therefore the systems provided higher content of SOC and consequently increased the OC-stock. The highest content of SOC was found in the area with sugarcane. The studied situations provided increase in the OC-stock in depth 0-10 cm, of 5,397 Mg ha-1, 3,494 Mg ha-1 and 1,964 Mg ha-1 for sugarcane, silvopastoral system and pasture. The management of fertilization and harvesting of sugarcane in the region of the city Governador Valadares is efficient in increasing the OC-stock, including being greater than the secondaryforest, and the silvopastoral site shows a greater potential in carbon stocking in the surface layers (0-10 cm and 10-20 cm) compared to continuous grazing areas.