Water conservation in tomato production using deficit irrigation and SALTMED model under greenhouse conditions

Abstract

The use of modeling for water conservation during irrigation is still in the research stage. There are many models can be used for this purpose, including Saltmed model. The SALTMED model is a holistic model can be used for different irrigation water and soil qualities, variety of crops, and water irrigation systems. This research aimed to interpret the tomato yield using different water quantities and qualities under greenhouse experiments. The trial included deficit irrigation with 3 treatments (80 %, 60 %, 40 % along with 100 % crop water requirements (ETc), with three water qualities (ECw 1.0, 2.3 and 3.6 dSm−1). The outcomes of the SALTMED model indicate the potential of the model to interpret soil-water content, salinity and tomato yield in regions having semi-arid climates under deficit irrigation strategies. Results of the SALTMED model revealed that data was underestimated. Furthermore, the values range of the CRM coefficient of the residual mass were 0.005–0.055, -0.01–0.02, and -0.02–0.04 for 0.9, 2.3 and 3.6 dSm−1, respectively. Most salinity showed the CRM values 0.18 to -0.02, 0.2 to -0.41, and -0.05 to -0.38 respectively, for the three irrigation water qualities. The values of observed and simulated data predicted a good relationship obtained. For soil water content and salinity, R2 values ranged between 0.80–0.99 and 0.74–0.99 respectively. Model efficiently simulates tomato yield outcomes under saline and freshwater. The correlation between the simulated and observed yield were 0.92, 0.94, and 0.79 for water quality of 1.0, 2.3 and 3.6 dSm−1, respectively. Finally, the SALTMED model showed good simulations of soil water content, soil salinity, and final tomato yield.