Challenges to the Adaptation of Double Cropping Agricultural Systems in Brazil under Changes in Climate and Land Cover

The wide adoption of highly productive soy-maize double cropping has allowed Brazil to become one of the main producers and exporters of these commodities. However, land cover and climate change could affect the viability of double cropping due to a shortening of the rainy season, and both crops could be affected. The goals of this study were to evaluate if adaptation measures such as adoption of shorter-cycle cultivars and delaying sowing dates are effective to maintain soybean and maize yield in the main producing regions in Brazil. We used a crop model and four climate models to simulate double cropping in two climate scenarios that differ in Amazonia and Cerrado deforestation levels. We tested if 10 soybean and 17 maize sowing dates and three cultivar combination could reduce the impacts of a shorter rainy season in double cropping yield and gross revenue. Results showed a decrease in maize yield due to a delay of soybean sowing dates and rainfall reduction during the growing season. Adaptation through delaying sowing dates and the adoption of short cycle cultivars was not effective to maintain system revenue in all the study regions in a scenario with high deforestation levels.