Effect of Saline Water Irrigation on Soil Moisture and Salinity and Modeling Transpiration of Greenhouse-Grown Tomato in Response to Salt Stress

Fresh water shortage is a major limiting factor for the development of greenhouse agriculture in arid regions. Brackish or saline water irrigation is an important approach to address this issue. However, the salts from irrigation water are also brought into the soil. If the salts accumulate in the crop root zone, it may have a negative effect on crop growth. In this study, a greenhouse experiment was carried out to evaluate the influence of saline water irrigation on soil moisture and salinity and to examine the response of tomato transpiration to salt stress. The treatments comprised of three salinity levels (0.4 g L-1 (fresh water; control), 3.4 g L-1 and 6.4 g L-(1;) denoted as T1, T2 and T3, respectively). Results showed that saline water irrigation significantly increased soil moisture and salinity, while no obvious difference was observed in root length density distribution among the treatments. Further, a method was developed to optimize the parameters in tomato transpiration model using the data from T3 treatment and the results were validated using the data from T2 treatment We found that the optimized model could well simulate the effects of salt accumulation on tomato transpiration. Overall, our results would provide theoretical and technical support for soil salt regulation and sustainable saline water utilization for greenhouse agricultural production. (C) 2020 Friends Science Publishers