Response of AquaCrop Model to Different Irrigation Schedules for Irrigated Cabbage

Agricultural sector faces the challenge to produce more food with less water by increasing crop water productivity. As such, the question of improving the present level of crop water productivity in general and for irrigation in particular assumes a great significance in perspective water resource planning. This study was undertaken to improve water productivity, i.e., ‘more crop per drop.’ In this study response of cabbage to different irrigation schedules under mulch and non-mulch condition using calibrated AquaCrop model was evaluated. AquaCrop is a crop model that simulates yield response to water developed by FAO and is appropriate to consider effects where water is the limiting factor for crop production. AquaCrop was calibrated for cabbage (Brassica oleracea var. capitata), a leafy vegetable. Simulations were carried out for the period November 27, 2013, to February 19, 2014 with T1, T2, T3 (treatments irrigation scheduling at 50 % moisture depletion of available water capacity under black, silver, and no polyethylene mulch with drip irrigation) and T4, T5, T6 (irrigation scheduling at 100 % evapotranspiration under black, silver, and no polyethylene mulch with drip irrigation). The model provided excellent simulation of canopy and yield. The harvest index was observed as 80 % for cabbage. Formulated Schedule with S1, S2, S3, S4, and S5 (irrigation schedule at 110, 90, 80, 70, and 60 % ETc) and S6, S7, S8, S9, and S10 (mulch + Irrigation schedule at 110, 90, 80, 70 and 60 % ETc). S8 saved 25.19 % water with only 4.63 % reduction in the yield of cabbage head compared to control and resulted in water use efficiency as 6.05 kg m−3. Thus S8 is recommended to be used for cabbage production, to water productivity.