Emission of CO2 and Organic Carbon Content in Different Pasture Management Systems

Abstract

Inadequate soil management is one of the primary causes of pasture degradation, aggravated by the replacement of natural forest environments with cultivated pastures. Thus, the objective of the present study was to quantify the flux of CO2 and organic carbon of the soil in grasslands undergoing intensive and extensive management, and in a native forest. The experiment was conducted in a randomized block design, with three treatments: intensive management system (IMS), extensive management system (EMS), and native vegetation (NV). The collected soil variables consisted of CO2 flux, organic carbon, temperature, and humidity. The CO2 flux quantification was obtained using LI-COR 8100-A equipment, chamber model 103. Carbon determination was performed according to EMBRAPA methodology, and soil temperature and humidity were plotted using a model 5TM Decagon Devices® sensor. The respective mean CO2 flux values for the IMS, EMS, and NV were 2.18; 4.04, and 1.69 μmol CO2 m-2 s-1, and the values ​​found for organic carbon content were 32.9; 24.3, and 14.9 g kg-1, respectively. The intensive management system exhibited higher CO2 flux from the soil to the atmosphere, and the soil containing native vegetation displayed greater values of organic carbon content.