Calibration and validation of the FAO AquaCrop water productivity model for cassava (Manihot esculenta Crantz)

Joost Wellens, Dirk Raes, Elias Fereres, Jan Diels, Cecilia Coppye, Geraldine Adiele Joy, Kodjovi Ezui, Augusto Becerra, Michael Selvaraj Gomez, Gerd Dercon, Lee Kheng Heng. (1/4/2022). Calibration and validation of the FAO AquaCrop water productivity model for cassava (Manihot esculenta Crantz). Agriculture Water Management, 263.

Abstract

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.