Salt Tolerance of Plants

Many plant, soil, water, and environmental factors interact to influence the salt tolerance of a plant. This chapter presents the salt-tolerance data as well as tolerance limits for boron, chloride, and sodium. Plant tolerance to salinity is usually appraised in one of three ways: the ability of a plant to survive on saline soils, the absolute plant growth or yield, and the relative growth or yield on saline soil compared with that on nonsaline soil. Temperature, relative humidity, and air pollution are important climatic factors that influence plant response to salinity. The salt tolerance of woody crops is complicated because they are also influenced by specific salt constituents. Crops irrigated by sprinkler systems are subject to additional salt damage when the foliage is directly wetted by saline water. Boron is an essential plant element but it can become toxic to some plants when soil-water concentrations exceed only slightly that required for optimum plant growth.