Agro-ecological differentials in soybean crop evapotranspiration and implications for adaptation to climate change.

This study estimated soybean crop evapotranspiration from weather data using the cropwat model. The effects of reference evapotranspiration, crop coefficients, and yield response factor were quantified for three different agroecological zones in Cameroon. The evapotranspiration of soybean was observed to be 281.03 mm in the farming district of Ambam, 387.7 mm in Bamenda and 605.3 mm in Garoua, indicating pronounced differences in the agro-ecologies. Across the three regions studied, rainfall pattern determines soil water reserves and crop water uptake. In the farming zones of Bamenda and Ambam, water requirement for soybean are met by the rainfall. In the northern region of the country, irrigation needs are high. As a consequence, actual crop evapotranspiration is greatest in the hot dry zone of Garoua and lowest in the cool humid region of Bamenda. From this study it could be concluded that coping with climatic variations and future climate change will require complementary irrigation as well as improved crop management practices.