The role of Cerrado agriculture in mitigation of climate change: intensification of agroecosystems and soil carbon balance

Abstract

The intensification of human activities and the increase in the concentration of Greenhouse Gases (GHG) in the atmosphere have accentuated the process of climate change. Land-Use Change (LUC) and the consequent loss of Organic Matter (OM) from the soil in agricultural areas is seen as one of the activities with the biggest contribution to GHG emissions in Brazil. In this sense, the adoption of management practices is essential to mitigate climate change and ensure sustainable agricultural development. The objective of this project is to evaluate the impacts of the conversion of native forest for agricultural use at different levels of intensification on the soil carbon (C) balance, and on the OM quality in the Brazilian Cerrado region. Soil samples will be collected up to 1 m deep, in the localities of Sapezal - MT, Costa Rica - MS, and Cristalina - GO. The treatments will comprise areas managed under different tillage systems (conventional system and no-tillage), and crop intensification levels (crop succession and rotation). Changes in total soil C and N stocks will be quantified, as well as in the OM fractions obtained by physical fractionation of OM. Additionally, the fluxes of CO2, N2O, and CH4 gases will be measured, which will later be used to estimate the soil C balance. Finally, spectroscopic techniques such as nuclear magnetic resonance will be used to assess changes in OM composition. The data obtained will be submitted to analysis of variance, and when significant, to the Tukey mean comparison test (p < 0.05). Multivariate techniques will be applied to identify the relationship between measured variables and evaluated systems. The results will contribute to the improvement of production systems that are capable of generating a positive C balance in the soil, contributing to the development of sustainable agriculture in the Cerrado region. (AU)