Irrigation with saline-sodic water: Effects on soil chemical-physical properties

The results of a two-year research, aimed at studying the effect of irrigation with saline and sodic water on soil physical and chemical properties, are reported. Bean and capsicum were grown in pots filled with two different clay-loam soils, irrigated with 9 types of water obtained from the factorial combination of three salt concentration levels (0.001 – 0.01 – 0.1 M for bean, and 0.01-0.032- 0.1 M for capsicum) with three sodium adsorption ratio (SAR) levels (5, 15 and 45) and were subjected to two leaching fractions (10 and 20%). The results did not show any significant effect of irrigation water’s salinity and sodicity, and of the leaching fraction, on soil type. The use of irrigation water with 0.1 M salt concentration caused an increase in electrical conductivity (ECe) from an initial average value of 0.71 dS m -1 to 13.9 and 19.5 dS m -1 , at the end of the first and the second irrigation season, respectively; small variations were, instead, observed, for soil pH. Despite the use of leaching fractions, any increase in the salt concentration and SAR of irrigation water resulted in an increase in the exchangeable Na percentage and a decrease in the exchangeable K, Ca and Mg.