Weather Determined Relative Sensitivity of Plants to Salinity: Quantification and Simulation

Abstract

The amelioration of plant salinity tolerance due to reduction in potential evapotranspiration is a long recognized phenomenon. In spite of this, salinity tolerance of plants is generally calculated from full season, time‐ and space‐averaged response data. We hypothesized that the HYDRUS‐1D model could be used to predict dynamic changes in plant salinity tolerance for a greenhouse vegetable crop over a full season and to determine best management practices regarding blending of saline with desalinated water for optimization of yields and water use efficiency (WUE). The specific objectives of the study were to determine dynamic vapor pressure deficit (VDP)–salinity response relationships of bell pepper plants grown in lysimeters and to apply them for hypothetical management scenarios when irrigating with blended desalinated and brackish water under commercial conditions. The transpiration response of bell pepper plants to salinity in the controlled lysimeter experiment was strongly influenced by variations in potential transpiration throughout the season. The plants were relatively tolerant during periods of low VPD and relatively sensitive during periods of high transpiration demand. Data were used to develop salinity response equations as a function of VPD. In a case study for Israel's Arava Valley, transpiration and water productivity of bell peppers could be increased 5% by blending saline and desalinated water such that less saline water was applied during periods of relatively high sensitivity (high VPD) and more during periods of relative tolerance as compared to application of the same total of both sources of water blended at a constant ratio throughout the season. Sensitivity analysis of the dynamic crop response model revealed that such increases in water productivity would be even greater for more salt sensitive crops.

Recent Developments and Applications of the HYDRUS Computer Software Packages

“…Such problems can be addressed with HYDRUS using two approaches. One would be to use the standard HYDRUS models by assuming that salinity behaves more or less like an inert tracer and hence is now subject to chemical reactions (e.g., Hanson et al, 2008; Dudley et al, 2008; Roberts et al, 2009; Groenveld et al, 2013). An alternative is to use the UnsatChem module, which considers the transport and reactions between major ions (e.g., Gonçalves et al, 2006; Ramos et al, 2011).…”

Water flow and multicomponent solute transport in drip‐irrigated lysimeters

“…Considering specific solute uptake could help describe processes such as ion toxicity and subsequent water uptake reductions. Solute uptake could also be important in quantifying moderate changes in the soil solution composition, especially for irrigation with varying water qualities [ Groenveld et al ., ; Silber et al ., ]. Combining multicomponent root uptake models, such as the one presented by Silberbush and Ben‐Asher [], in soil‐based models such as HYDRUS (2D/3D), could improve simulations of cropping systems [ Schröder et al ., ; Raij et al ., ].…”

“…Parameters defining the S‐shaped water uptake reduction functions for water and osmotic stresses are defined in Table as calculated in Groenveld et al . [] for similar conditions. Compensated root water uptake was considered by setting the critical stress index to 0.5 [ Šimůnek and Hopmans , ].…”

“…Miscalculations and high daily variability of ET or timing and magnitude of rain events can lead to inefficient use of water and fertilizers, resulting in economic losses and to groundwater pollution from leached agrochemicals [ Oren et al ., ; Corwin et al ., ]. Leaching fractions are commonly based on crop response functions determined for an entire season and average root zone salinity, which may not be relevant for all actual temporal or spatial field conditions [ Letey et al ., ; Groenveld et al ., ]. Crop factors have additionally been shown to be sensitive to a reduction in transpiration due to salinity and other types of stresses [ Rhoades et al ., ; Bhantana and Lazarovitch , ].…”

Comparison of water and osmotic potentials on Vigna unguiculata stress response

“…In addition, plant stress tolerance is strongly correlated to the potential transpiration rate (Perelman et al, 2020). Therefore, it is also important to understand the increased transpiration by responding to changes in plant stress tolerance (Groenveld et al, 2013).…”