INTEGRATED AGRICULTURAL SYSTEMS AND CLIMATE CHANGE IMPACTS ON SOIL CARBON STORAGE IN BRAZILIAN DRYLANDS

Abstract

In Brazil, land use change and the agricultural sector are responsible for more than 70% of greenhouse gas emissions. Climate change is increasing the frequency of droughts, which, combined with altering precipitation patterns, compromises agricultural production in drylands. In this sense, adopting agricultural management practices that increase the potential for carbon (C) sequestration in the soil is essential to face the process of climate change. Therefore, this project aims to use the DayCent model to predict changes in soil carbon stock in different agricultural systems under future climate scenarios in Brazilian drylands. Soil samples were collected up to 1 m deep, in the locations of Sobral (CE), Betânia do Piauí (PI), and Petrolina (PE). The treatments at these three sites comprise areas managed under different levels of intensification (intercropping and agroforestry). Soil C and N stocks in the study area were quantified. This information will be organized and used in the DayCent model to calibrate and evaluate the model. Once DayCent has been improved for modeling the dryland systems in Brazil, long-term simulations (2050 and 2100) will be carried out to estimate changes in SOM, C, and N stocks, considering the current uses/treatments evaluated in the study areas. Finally, new scenarios will be predicted considering management strategies and climate change projections (IPCC scenarios). With this project, we expect to identify the best long-term strategies capable of increasing the potential of agricultural systems to mitigate and adapt to climate change in Brazilian drylands. These results will contribute to improving national inventories that are essential for establishing initiatives that seek to cooperate with the global climate agenda and achieve C neutrality.