Variação no estoque de carbono em sistemas agrícolas

Abstract

Since the Industrial Revolution, the amount of greenhouse gas emissions has increased significantly, thus contributing to global warming. Given that carbon dioxide is the major contributor to this warming, studies of mitigation measures are of paramount importance, with carbon stock in the soil being one of these viable measures to minimize some of the impacts on the environment. Thus, this study aimed to evaluate the carbon stock in the Savana native vegetation soil, in areas of conventional system with corn and cassava planting, and area with intercropping cassava corn. The experiment area is located at the Agrotechnological Center of Palmas – TO. In each area soil samples were taken from two different depths: 0-10 cm and 10- 40 cm. The experimental design was completely randomized in a 4x2 split plot scheme with 5 replications each, totaling 40 experimental plots. The variables studied were: humidity, density, organic matter, total organic carbon and carbon stock. Higher depths tend to have a higher moisture content. At a depth of 10-40 cm, the native vegetation presented the highest organic matter content and the intercropping cassava corn the lowest content. Both areas with cassava, single or intercropped, the soils presented higher density. The corn and cassava intercropping area also had the lowest total organic carbon content at a depth of 10-40 cm, while native vegetation at the same depth obtained the highest content. In the carbon stock, it was observed that greater depths tend to store more carbon, with the areas with cassava and native vegetation, having the highest values. However, it is important to note that optimal management is one that aggregates the most organic matter without compacting the soil, even if this results in a lower carbon stock value in the soil. Thus, the least carbon efficient system was the one where cassava and maize were intercropped.