Application of AquaCrop model in deficit irrigation management of cabbages in Keiyo Highlands

Abstract

Crop growth can be simulated under different water application using simulation models. The main purpose of deficit irrigation is high water productivity with less application of water to plants. In this research, the potential of AquaCrop to simulate the growth of cabbages in Keiyo Highlands (0°22’45’’N and 35°32’9”, 2586 m.a.s.l) under nine different irrigation treatments in the dry season between December to February was studied. Statistical comparisons of observed and simulated biomass showed that R2 = 0.96, Root mean square error (RMSE) = 0.38 tons and coefficient of residuals = -0.17. The results showed that the model overestimated the biomass of cabbages. The model also provided excellent simulation of canopy and yield. In this study water productivity of 17 g/cm2 and Harvest index of 76% were found for cabbages.   Key words: Deficit irrigation, AquaCrop, cabbage ‘Riana’ and water productivity.