Modeling tomato evapotranspiration and yield responses to salinity using different macroscopic reduction functions

Abstract

Plant responses to salinity can be used to manage irrigation with brackish water. This study evaluated effects of brackish water irrigation on tomato (Solanum lycopersicum L.) plants, proposed a new model to describe plant relative evapotranspiration (ET) and relative yield as a function of electrical conductivity of soil saturated paste extract (EC e), and compared the estimations of the new model with four other models (linear model of Mass and Hoffman, and three nonlinear models of van Genuchten, Dirksen, and Homaee). A greenhouse experiment was conducted with five salinity treatments: tap water of EC 0.6, brackish groundwater of EC 2 and 3, and reverse osmosis (RO) of EC 4 and 6 dS m −1. Results indicated no changes in leaf photosynthesis rate (P n), transpiration rate (T r), and stomatal conductance (G s) up to 2 dS m −1 irrigation water salinity. Nonlinear models better described tomato yield and seasonal ET. The proposed new model performed best when compared with four previous models to predict tomato yield and ET responses to salinity. The calculated soil salinity threshold values (EC e *) from the new model were 1.73 dS m −1 for yield and 2.52 dS m −1 for ET. Data from published studies on effects of irrigation water salinity (EC w) on tomato yield and ET were analyzed to validate models. The results showed that the new model was simpler and superior in estimating plant responses to EC w. Tomato is a salt-sensitive crop, and irrigation with brackish waters adversely influences growth and ET.

Brackish groundwater and reverse osmosis concentrate influence soil physical and thermal properties and pecan evapotranspiration

“…Aboveground plant biomass was lower for RO irrigated trees than the control treatment and that decreased the total ET further. Our results also agreed with other published studies for glycophytes (Baath et al, 2020;Yang et al, 2020) and halophytes (Flores et al, 2016;Katerji et al, 2009;Ozturk et al, 2018), where the plants biomass decreased with increasing salinity with attendant decreases in the ET. Noaman and El-Haddad (2000) also reported decreases in ET with increasing irrigation water salinity ranging between 2 and 6 dS m −1 .…”

“…They have gotten attention because they depend on soil water content (Cosenza et al, 2003;O'Donnell et al, 2009) and influence the energy partitioning at the soil surface, soil temperature, and the transfer of heat and water across the soil surface (Ochsner et al, 2001). Higher water content is reported in soils irrigated with brackish waters (Yang et al, 2020). According to Modi et al (2013), thermal conductivity was higher when the moisture content was high, and it decreased with decreasing soil moisture content.…”

Energy and Water Related Parameters in Tomato and Cucumber Greenhouse Crops in Semiarid Mediterranean Regions. A Review, Part II: Irrigation and Fertigation

“…For instance, Phogat et al [47] suggested that annual gypsum application at a rate of 1.7 t. ha −1 together with a leaching fraction of at least 20% was adequate for managing this soil salinity and sodicity hazard. The calculated soil salinity threshold values for yield decline were 1.73 dS m −1 for EC e and 2.52 dSm −1 [48]. Controversially, in soilless tomato crops, water with electrical conductivity up to 4.0 dS m −1 positively affected photosynthetic rate, crop growth [49] and fruit taste quality characteristics.…”

Transdisciplinary contributions and opportunities in soil physical hydrology

“…Irrigation, soil, and plant specialists have interacted ever since to derive strategies to overcome soil and water quality problems from salinity while creating solutions for growers who depend on efficiency and functionality of crop irrigation. Whereas focused on long-term soil salinity dynamics, Yang et al (2020) investigate the potential risk of using brackish water for irrigation, especially with regard to crop yield and effects on evapotranspiration (ET). At the same time, they develop a new model to detect threshold values for the electrical conductivity (EC) of either saturated soil paste or irrigation water as an important indicator for water quality.…”