Effects of Salinity on Growth,Water-Use Efficiency,and Nutrient Leaching of Three Containerized Ornamental Plants

The scarcity of water in the Mediterranean area has frequently led to the use of saline water to irrigate ornamental plants in nurseries. Aloe vera L. Burm, Kalanchoe blossfeldiana Poelln, and Gazania splendens Lem. plants were grown in a greenhouse from the University of Almeria in containers with a mixture of sphagnum peat moss and perlite in order to evaluate the effect of salinity levels on plant growth, water-use efficiency, and nutrient leaching. The experimental design consisted of three salinity treatments, four blocks, and four plants (one plant per container) per treatment-block giving a total of 12 plants per species plus border plants placed around the perimeter of the treatment plants to maintain uniform growing conditions for treatment plants. At the end of the experiment, plant dry weight and water-use efficiency were assessed for each salinity treatment. Leachate was collected weekly and analyzed for concentrations of nitrate-nitrogen, phosphate-phosphorus, potassium, calcium, and magnesium (NO₃^–N, PO₄^3–P, K⁺, Ca²⁺ and Mg²⁺). Increasing salinity levels of irrigation water reduced the plant dry weight in all species and affected the leachates volume and their nutrients concentrations. We suggest the use of low salinity levels in water to improve the growth and to reduce the environmental impacts of nutrient runoff.