Climate change scenarios and their impact on water balance and sugarcane yield in Southern Brazil

Sugarcane is one of the main extensive crops in Southern Brazil, covering around 8 million ha. The crop is mainly produced under rainfed conditions, which makes the sugarcane sector very susceptible to climate variability and change. The study of the agro-environmental vulnerability of the sugarcane crop is an essential aspect to determine the yield potential, the climate risks and to conduct the crop planning at medium and long terms. Based on the economic and social importance of sugarcane crop for Southern Brazil and the expected future scenarios of climate change for this region, reported by the IPCC and the First Brazilian Report on Climate Change, the present study had as objectives to assess the impacts of different climate changes scenarios on the water balance and on the potential and actual yields for the main sugarcane production regions of the state of São Paulo, Brazil. For that, twelve climate changes scenarios, with increasing temperatures and CO2 concentrations in the atmosphere, and varying changes in rainfall were generated for the years of 2030, 2060 and 2090. The results indicated that, even with the huge impact of climate change on the water balance of all locations, the potential and actual yields may increase substantially as a function of the combination of higher air temperatures, higher CO2 concentration and also better management practices in the future scenarios. By 2090, even with a higher water deficit, the sugarcane actual yield may increase by 82, 71, 51 e 59%, respectively for Araçatuba, Assis, Jaboticabal and Piracicaba, which indicates an improvement on the water use efficiency. Based on that, sugarcane stands up as a very important crop to face climate change in Brazil and around the world