Climate change impacts on regional maize yields and possible adaptation measures in Argentina

In this work, the impact of future climate (2081-2090) on regional maize yields was assessed through a crop simulation model. The climatic inputs correspond to the regional model MM5/CIMA, considering grids of 50 km * 50 km. Crop model runs were done under typical crop management conditions with and without considering the fertilisation effect of CO2. Without CO2 effects, the impact of future scenarios will be negative in most of the region, attaining mean reductions of 9% and 6% under SRES A2 and B2, respectively. However, yield changes could range between increases of 46% under B2 and decreases of 17% under A2. The inclusion of CO2 effects led to increases in maize yields by 19% under A2 and 11% under B2, although negative impacts could still occur. The adaptation measures related to planting dates and irrigation were assessed as a way to overcome future negative impacts. Without considering CO2, advancing sowings by 15-30 days could be beneficial, increasing yields under B2 and reducing loses under A2. Irrigation requirements could, on average, increase in the central and northern parts of the region and decrease in the southern one. The uncertainties related to future scenarios and the crop responses to CO2 are also discussed.