Irrigation water quality and ion balance in leaves of deciduous ornamental trees

Abstract

In arid and semi-arid regions, evaporation losses exceed replenishment from fresh water tributaries reducing water quality due to accumulation of salts. Increasing human demand for high-quality waters has encouraged use of lowquality, nonpotable water for landscape and agricultural irrigation. However, when used alone for irrigation, growth and appearance of some woody ornamentals are negatively impacted. To date, little is known of the impacts of low-quality water on ion uptake and salt tolerance of most ornamental plants. Three replications of five deciduous ornamental trees were randomly planted and treated with three blended irrigation waters of high-, medium-, and lowquality water [15, 80, and 120 mg sodium (Na) L 1 , respectively] in a split-plot design. Leaf tissues were sampled on October 1996 and September 1997 and analyzed for nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), Na, zinc (Zn), iron (Fe), manganese (Mn), and copper (Cu). The five tree species varied in their responses to irrigation treatment with water of decreasing quality with some having increasing and others decreasing contents of a specific nutrient element. Further, although impact of lowquality water was evident, none of the minerals tested were in the deficient or toxic range.

Growth and Physiological Responses of Landscape Plants to Saline Water Irrigation: A Review

“…In addition to these visible changes reflected in plant growth/size and foliar damage, plants also respond to salinity internally, expressed in changes in physiological and metabolic processes. To quantify the physiological responses to salinity, photosynthesis, leaf conductance, chlorophyll fluorescence, chlorophyll content, ion uptake, and accumulation in tissues are typically measured (Cabrera, 2003;Eom et al, 2007;Niu and Rodriguez, 2006a;Quist and Williams, 1999;Wu et al, 2001;Zollinger et al, 2007;Zribi et al, 2009).…”