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FAO's water-driven crop growth simulation model, AquaCrop, was calibrated and validated for cassava (Manihot esculenta Crantz). Existing datasets, used in similar published works, were shared covering several years and regions (Colombia, Nigeria and Togo). Different varieties were tested for the case of Colombia and a single variety (TME-419) for Nigeria and Togo. Overall calibrated biomass simulations resulted in an R2 of 0.96 and a RMSE of 1.99 tonne DM/ha. As for dry tuber yield estimates, it was not possible to find a single harvest index for the ensembled varieties given their varying characteristics and limited data per variety. However, for the TME-419 variety (Nigeria and Togo) calibrated root tuber simulations yielded and R2 of 0.94 and a RMSE of 2.37 tonne DM/ha. A single crop-file was developed for different cassava varieties and agro-ecological regions, which can be applied with confidence to further study cassava related food security, water productivity, improved agronomic practices, etc. • A cassava crop-file was calibrated and validated for AquaCrop. • Different priorly published cassava datasets were used. • A single crop-file was developed for different varieties and ecological regions. • AquaCrop can be used to improve crop water productivity and agronomic practices. [ABSTRACT FROM AUTHOR]

• Crop yield is expected to fall by 5–20% without adaptation. • Cultivation of current sorghum cultivars could become unfeasible in the Sahelian zone. • To benefit optimally from CO 2 fertilization, soil fertility should be improved. • Irrigation of (currently) rainfed crops is recommended only if soil fertility is improved. The effect of climate change on crop yield in smallholder farms was simulated using the FAO's crop water productivity model AquaCrop and climate change projections from various climate models. This was performed for emission scenarios RCP 4.5 and 8.5 and for time horizons 2030 and 2050. Although the variation in inter-annual rainfall is projected to be substantial, the median projected change in total rainfall is predominantly slightly positive in future years. The climatic changes considered involve temperature increases of between 1.0 °C (2030) and 2.5 °C (2050), and an increase in evapotranspiration of between 3% (2030) and 7% (2050). An in-depth analysis was carried out in four pilot countries: The Gambia, Côte d'Ivoire, Mali and Niger. Four crops and two cultivation methods were considered: irrigated tomato, rainfed sorghum, and rice and maize cultivated both under irrigated and rainfed agriculture. Projections show that if management practices are not improved, climate change will have a negative impact on agricultural production. On average, yield is expected to decline by 5 to 20%, depending on the crop, agro-ecological zone and time horizon. Simulations indicate that the cultivation of sorghum in the Sahelian zone may no longer be feasible under future climatic conditions. If management practices are not improved, the yield gap increases with climate change. To benefit from CO 2 fertilization in future years, future soil fertility needs to increase by at least 15 to 20% in order to maintain current levels. Improved fertility management could lead to an increase in crop yields of between 5 and 14% for irrigated tomato and irrigated and rainfed rice. The impact of future climate changes on maize yield, maize being a C4 crop which benefits less from CO 2 fertilization, was mostly negative even with improved soil fertility management. [Display omitted] [ABSTRACT FROM AUTHOR]