Site Suitability Assessment for Irrigating Urban Landscapes with Water of Elevated Salinity in the Southwest Consolidated Final Report Part I. Water Quality and Plant Salt Tolerance
With increasing population and the demand for potable water, water with elevated salinity and reclaimed water are now commonly used for irrigating urban landscape in many communities in the arid Southwest. It not only saves potable water, but also provides the stable supply of irrigation water for maintaining urban greenery and recreational facility, usually at a discounted price. There are many examples of successful use of water with elevated salinity, such as shown in Fig. 1-1. At the same time, there have been reported cases of landscape quality degradation in some of these use sites. The degradation includes foliar damage, stunted growth, premature defoliation, and in some cases, tree mortality. Thinning of turf covers is also reported, especially in sports fields irrigated with water of elevated salinity.
In order to reduce the incidences of landscape quality degradation, Texas AgriLife Research Center at El Paso, in cooperation with both water providers and water users, has been investigating salt tolerance of various landscape plants, and the levels of salt accumulation in different types of soils. The main source of funding came from the Rio Grande Basin Initiative through the Texas Water Research Institute, matched by a local fund from El Paso Water Utilities. The Bureau of Reclamation USDI provided a fund through the Water Conservation Field Service Program to develop soil suitability guidelines, which is shown in a companion report. This report covers spray and soil salinity tolerance of landscape plants, and describes how the information can be used for assessing site suitability. Management capabilities of water users undoubtedly affect quality of landscape, and for this reason, it is an important factor in assessing site suitability. However, it is beyond the scope of this guideline.
This project was assisted by a number of student workers from the University of Texas at El Paso. The task of preparing this report was assisted mainly by Doriana Torres and Yvette Pereyra, student workers. David Ornelas and David Tirre from El Paso Water Utilities have cooperated with our investigation of salt tolerance of landscape plants.