Comparison of water productivity and crop performance in hydroponic and soil cultivation using AquaCrop software* A case study of lettuce cultivation in Pakdasht, Iran

Soil cultivations are widely being replaced by soil-less methods for growing plants in greenhouses. In the present study, we compared the normalized water productivity (WP*) of lettuce plants under soil and hydroponic cultivation methods. Furthermore, the AquaCrop model was assessed for the simulation of yield and water productivity (WP) of lettuce in the soil and hydroponic cultivation methods. Productivity parameters of normalized water were different for the soil and hydroponic cultivations. The AquaCrop model was applied using 14.3 and 15.8 g m(-2), respectively, as obtained for WP* for soil and hydroponic cultivation methods in the first cultivation. Biomass was simulated during the growth period and was compared with the measured data from the first cultivation. The results indicated that the AquaCrop model simulates the performance of lettuce with a remarkable accuracy during the growth period using the calibrated values of WP*. In both cultivations, WP was also measured and simulated for the plants grown with the hydroponic and soil cultivation methods. WP of plants cultured in the hydroponic system was higher than the WP of soil-grown plants. Canopy cover was measured for both cultivation methods and was simulated by the model. The model simulated the canopy covers remarkably well for both cultivation methods (coefficient of determination R-2 > 0.95). Therefore, this model can be considered reliable in investigating the effect of cultivation methods on WP and biomass in lettuce plants.