Tortillas on the roaster (ToR): central America maize-beans systems and the changing climate

Abstract

In order to be able to adapt to climate change, maize and bean producing smallholders in Central America have to know which type of changes and to which extent and ranges these changes will occur. Adaptation is only possible if global climate predictions are broken down on local levels, to give farmers a direction on what to adapt to, but also to provide detailed information about the extent of climate change impact and the exact location of the affected population to local, national, and regional governments and authorities, and the international cooperation/donors in order to coordinate and focus their interventions This technical report seeks to assess the expected impact of climate change on maize and bean production in four countries in Central America. We downscaled GCM (Global Climate Models) to a local scale, predicted future maize and bean production using the dynamic crop model DSSAT (Decision Support for Agro-technology Transfer), we identified based on the DSSAT-results 3 types of focus areas where impact is predicted to be significant and run DSSAT again with the full range of available GCMs to address uncertainty of model predictions. Outputs of downscaled climate data show that temperature is predicted to increase in the future, while precipitation will slightly reduce. Crop modeling shows that bean yields will decrease high along the dry belt in Central America and revealed a significant influence of soil fertility and soil water retention capacity especially on maize yield which will be drastically affected by climate change under such poor soil conditions. Furthermore, we identified hot-spots with more than 50% yield reduction as well as area with favorable growth conditions in the future. The conducted vulnerability analysis shows the low adaptive capacity at household level and the low availability of human and social capital across the region for climate change adaptation. Central America is highly vulnerable to climate change. Based on the results we finally made recommendations for adaptation- and mitigation strategies such as eco-efficient and sustainable intensification of the production system combing soil and fertility management with water harvesting schemes, marketed oriented high value plant production and plant genetic improvement for heat- and drought stress. The findings of the present study should enable decision makers on local, national and regional levels to take appropriate action in the right locations and provide an adequate policy framework for successful implementation of adaptation strategies in the rural sector of Central America.