Estimating soil carbon changes regarding sugarcane expansion into pastures in Brazil

Abstract

The environmental impacts of land use change (LUC) caused by sugarcane expansion have generated numerous questions regarding the environmental sustainability of Brazilian ethanol production. Most of these uncertainties are about the effects of LUC on soil organic matter (SOM). The mainly goal of this research internship abroad, which is linked with the FAPESP research project n° 2014/08632-9, is to evaluate changes in SOM due to the expansion of sugarcane into pasture areas in South-Central Brazil, using the GEFSOC modelling system. Specifically, our objectives are to: i) estimate changes on C and N stocks due to the conversion of areas under native vegetation to pastures; as well as changes associated with the expansion of sugarcane into pasture areas; ii) compare the results of the simulations with data obtained in situ in areas of the project linked with this proposal and others obtained from literature; iii) develop prospective scenarios of sugarcane expansion of sugarcane into pasture areas in South-Central Brazil, as well as related changes in C and N stocks. Soil sampling and analytical analyses have been completed and historical and management data were obtained from interviews. During the internship at the Natural Resource Ecology Laboratory, simulations will be carried out on the effects of LUC on SOM in areas of sugarcane expansion at South-Central Brazil, using the GEFSOC modelling system. The results generated during the research internship will be extremely useful in assessing the environmental sustainability of sugarcane ethanol and for guiding expansion policies of sugarcane production in Brazil. (AU)