EFFECT OF SALINE WATER ON SOIL-SALINITY AND ON WATER-STRESS, GROWTH, AND YIELD OF WHEAT AND POTATOES

Wheat and potatoes were grown in tanks filled with loam and clay and i rrigated with water of three different levels of salinity and, for the wheat. with two irrigation regimes. A combination of soil water sampl ing and salt balance was used to study the development of soil salinit y and the composition of the soil water. This revealed an increase in adsorbed sodium, a decrease in adsorbed calcium and magnesium, and pre cipitation of a mixture of calcium and magnesium carbonate. Predawn le af-water potential and stomatal conductance can be used as parameters for water stress, and show good coherence with growth and yield. That potatoes are more sensitive to water stress than wheat was reflected b y greater differences in leaf-water potential and stomatal conductance . and a more severe yield decrease. Soil, salinity and water regime af fect water stress, growth. and yield. The water efficiency of wheat an d potatoes was not affected by soil and salinity.