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.

中文翻译：

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使用不同的宏观还原函数模拟番茄的蒸散量和产量对盐分的响应

植物对盐分的反应可用于管理咸水灌溉。这项研究评估了咸水灌溉对番茄（Solanum lycopersicum L.）植物的影响，提出了一个新模型来描述植物相对蒸散量（ET）和相对产量与土壤饱和糊状提取物（EC _e）电导率的关系，以及将新模型的估计值与其他四个模型（Mass和Hoffman的线性模型以及van Genuchten，Dirksen和Homaee的三个非线性模型）进行了比较。进行了五种盐度处理的温室实验：EC 0.6的自来水，EC 2和3的微咸地下水以及EC 4和6 dS m ^-1的反渗透（RO）。结果表明叶片光合作用速率没有变化（P _n），蒸腾速率（T _r）和气孔导度（G _s）高达2 dS m ^-1灌溉水盐度。非线性模型可以更好地描述番茄产量和季节性ET。与预测番茄产量和盐分的ET响应的四个先前模型相比，建议的新模型表现最佳。根据新模型计算得出的土壤盐度阈值（EC _e ^*）对于产量为1.73 dS m ^-1，对于ET为2.52 dS m ^-1。公开发表的关于灌溉水盐度影响的数据（EC _w）对番茄产量和ET进行了分析以验证模型。结果表明，该新模型在估计植物对EC _w的反应方面更为简单和优越。番茄是一种对盐敏感的作物，咸水灌溉对生长和ET产生不利影响。