Appraising salinity hazard to landscape plants and soils irrigated with moderately saline water. USDA under Agreement No. 4280001, El Paso Water Utilities and the Bureau of Reclamation

Water planners and managers are faced with the increasing needs to utilize nonpotable water for irrigating urban landscapes in water-shortage areas of the arid West. However, existing guidelines for assessing suitability of water for irrigation is rather broad. This paper presents updated guidelines based on the experience in west Texas and southern New Mexico where water of relatively high salinity (1000 – 3000 mg L-1) is used for landscape irrigation. Salinity hazard to landscape plants occurs through two different processes: foliar absorption of salts when plants are sprayed with sprinklers, and another through soil salinization. Foliar damage is widespread among broadleaf trees and shrubs, and occurs in sensitive plants when Na or Cl concentrations reach 150 mg L-1. When the concentration reaches 200 to 300 mg L-1, it affects nearly all deciduous trees, but not pines and junipers. This problem can be minimized through modification of sprinklers to low trajectory or to non-sprinkling types, otherwise through appropriate plant selection. Plant damage caused by soil salinization is also species–dependent, and occurs primarily in salt sensitive or moderately sensitive species. It is difficult to predict this form of salt damage from water quality data alone. Soil salinization potential has to be evaluate