Performance of the AquaCrop model in the climate risk analysis and yield prediction of cowpea (Vigna Unguiculatta L. Walp)

Abstract

The present work evaluated the Aquacrop model as a tool for climate risk analysis and yield prediction of cowpea, cultivated in a dystrophic yellow oxisol. The model was previously calibrated and validated for two harvests, in order to simulate the biomass and yield of cowpea, considering four applied water blades over its reproductive period. The good achieved results prove the model’s efficiency for this kind of simulation. After validation, the yield simulation of cowpea based on the meteorological data (2003 to 2014), soil and crop management of 12 harvests was performed. Two scenarios were given: the potential yield without water restrictions; and the actual yield, considering to pluvial availability conditions of the inserted series. The results suggested that the optimum sowing dates are between April 1st and 20th, in which there was a low yield loss (< 10 %) considering the potential yield, high probability (> 90 %) of achieving high yields (above 1300 kg ha-1) and a low risk of getting crop harvesting in the rainy period. After all, the model proved to be a feasible tool for predicting cowpea yield in the region and also over regions with similar characteristics.