Abstract:
Decision Support System for Agrotechnology Transfer (DSSAT) and Agricultural Production Systems
SIMulator (APSIM) were calibrated and evaluated to simulate sorghum (Sorghum Bicolor L.
Moench) var. Tegemeo under current and future climate in central Tanzania. Simulations for both
current and future periods were run assuming present technology, current varieties and current
agronomy packages to investigate rain-fed sorghum yield response. Simulations by both crop
models using downscaled weather data from eight General Circulation Models (GCMs) under the
Coupled Model Intercomparison Project phase 5 (CMIP5) and Representative Concentration Pathway
(RCP 4.5) by mid-century show a mixture of increase and decrease in median sorghum yields.
Four GCMs project yields to increase by 5% - 23.0% and one GCM show a decrease by 2% - 9%.
Model simulations under the remaining three GCMs give contrasting results of increase and decrease.
Adjustment of crop duration to mimic the choice of growing local cultivars versus improved
cultivars seems a feasible option under future climate scenarios. Our simulation results
show that current open-pollinated sorghum cultivars would be resilient to projected changes in
climate by 2050s but things seem better with long duration cultivars. We conclude that crop
simulation models show their applicability as tools for assessing possible impacts of climate
change on sorghum due to agreement in the direction of crop yield predictions in five out of eight
selected GCMs under projected climate scenarios. The findings provide useful guidance and motivation
to government authorities and development agencies dealing with food security issues to
prioritize adaptations policies geared to ensuring increased and sustained sorghum productivity
