Prediction of soil quality in areas irrigated with saline waters

Abstract

This work aims predicting salinization and sodification in two soils with different textures when they are irrigated with saline waters combined with different fertirrigation levels, and after the fall/winter rainfall washout of the soil. The electrical conduc­tivity of the saturation paste and of the soil solution was used as soil salinity indicator. The exchangeable sodium percentage (ESP) and sodium adsorption ratio (SAR) were used to characterize soil sodicity. Relation­ships between the indicators were studied with multiple regression analysis. The re­sults reveal that better predictions are ob­tained when the indicator SAR is used for the medium textured soil and when the irri­gation season and the rain washout period are taken into consideration, but for the coarse textured soil such predictions are best obtained only after the rain period. The ap­plied nitrogen also contributes to soil solution salinity only when low salt content is observed in the irrigation water. As a gen­eral rule, as the water quality decreases, ni­trogen applications contribute to diminish the soil solution salinity.