Brazil is one of the main producing and exporting countries of corn and soybean and a continental country with climatic diversity that allows the cultivation of these crops in various agricultural systems. Double cropping is a widely adopted system throughout the national territory, where it is possible to cultivate soybeans at the beginning of the growing season, followed by corn in succession, in the same growing season. The present study aims to systematize the scientific knowledge about the impacts of future climate change scenarios on yield and on the double-cropping system of soybean + corn in Brazil. Systematic review procedures were adopted. The soybean yield is projected to increase in all regions of Brazil under all climate scenarios. Corn yields under future climate scenarios are projected to decline, with the subtropical climate region being less affected than the northern regions. The double-cropping systems of soybean + corn tend to present increasing climate risks in tropical climate regions. Climate change scenarios point to a delay in the start of the rainy season that will delay the sowing of soybeans, consequently delaying the sowing of corn in succession, resulting in fewer rainy days to complete its cycle.

Soybeans are the most widely produced oilseed and the fifth most cultivated crop in the world. However, their growth and yield are significantly influenced by weather conditions. In Southern Brazil’s subtropical climate, farmers employ a double-cropping system, planting corn from late winter to early summer, followed by soybeans, which are sown after the corn harvest—typically in January—and harvested in autumn. This study argues that climate change has benefited late-sown soybeans in Rio Grande do Sul and will continue improving their growing conditions. The aim is to identify climate change’s past and future impacts on late-sowing soybean crop yields in this region. We evaluated the effects of climate on soybean yields using the HadGEM2-CC model (CMIP-5) for two scenarios (RCPs 4.5 and 8.5) and for two time periods (mid-and late-century). Additionally, the CSM-CERES-Maize model within DSSAT was also used to simulate corn yields under these climatic conditions. Our climatic analysis indicates an increase in rainfall and temperature, particularly in minimum temperatures, alongside significant rises in both minimum and maximum temperature extremes, and a reduction in frost days. Furthermore, higher atmospheric CO₂ levels are projected to enhance net photosynthesis, likely leading to increases in potential yield (Py) with rising CO₂ concentrations. Notably, the largest increases in achievable yield (Ay) are anticipated for early sowing dates under the mid- and late-century scenarios of RCP 4.5. Past climate changes have already improved the growth and yield potential of late-sown soybeans in Southern Brazil, a trend expected to continue as climate change further optimizes temperature and rainfall conditions. In conclusion, the late growing season for soybeans is predicted to be extended.