Evaluation of the RZWQM2 Model in Simulating Water Consumption, Water Use Efficiency, and Yield for Cabbage (Brassica oleracea. L)

Abstract

This study aims to verify the predictability of selected measured properties of soil and plants at depletion rates of available water and the use of soil conditioners using the root zone water quality model RZWQM2. A field experiment was conducted to cultivate the Cabbage crop for the autumn of 2021 at the field experiment station F / College of Agricultural Sciences in Al-Jadiriyah region, Baghdad- Iraq. The effect of depletion rates of available water and the addition of soil conditioners on dry weight, yield, water consumption, reference and potential evapotranspiration, water absorption by the plant, and the crop water use efficiency of the Cabbage plant was evaluated using the model RZWQM2. The experiment treatments were: D1: Irrigation after depleting 30% of available water, D2: Irrigation after depleting 60% of available water, C0: without addition, C1: adding organic matter (Compost) 20 Mg.ha-1, C2: adding perlite 4 Mg.ha-1, C3: adding organic matter (Compost) 10 Mg.ha-1 + perlite 2 Mg.ha-1. A scenario was created in the RZWQM2 model to simulate the studied traits at field conditions. The results showed that the percentage of depleting 30% of available water was better than the percentage of depleting 60% of available water using the RZWQM2 model at dry weight, yield, water consumption, reference, and potential evapotranspiration, water absorption by the plant, and the crop water use efficiency of the Cabbage plant. Also, the treatment of adding compost exceeded the rest of the conditioners and the comparison treatment at depletion rates of 30 and 60% of available water in the measured properties. Furthermore, adding compost reduced water consumption compared to the rest of the study treatments. Keywords: predictability; Irrigation; water absorption; evapotranspiration.