Impact of global warming on cowpea bean cultivation in northeastern Brazil

This study evaluated the effects of climate change on cowpea bean crop grown in northeastern Brazil based on the reports of the Intergovernmental Panel on Climate Change (IPCC). The water balance model combined with Geographic Information System techniques was used to identify regional areas where the cowpea bean crop will suffer yield reduction due to climate changes. Model input variables were: rainfall, crop coefficients, potential evapotranspiration and duration of the crop cycle. A limit value of 0.5 was adopted for the water requirement satisfaction index (WRSI), being the ratio of actual to maximum evapotranspiration. The acceptable seeding date was defined as the date at which the water balance simulation presented a WRSI value greater than the limit value, with a frequency of at least 80%. An increase in air temperature will cause a significant reduction in the areas currently favorable to cowpea bean crop growth in northeastern Brazil, and it is recommended that bean varieties better suited to high-temperature conditions should be planted.