Assessment of the Quality of Salt-Affected Soils After Irrigation and Cultivation in Semi-arid Condition

Abstract

This study investigates morphological, physicochemical properties and clay mineralogy of four soil types belonging to salt-affected soils after converting into cropland. The data showed that strong platy to the medium prismatic structure of salt-affected soils was replaced by the fine angular blocky structure in cropland mainly as a result of the improvement in organic matter caused by agricultural practices and wetting–drying cycle accelerated by irrigation. After cultivation, two decreasing and increasing trends were observed in clay content (a drop of 17–51%) and sand (a rise of 8–96%), respectively. There was a remarked depletion in the values of soil pH (0.17–0.78 unit), calcium carbonate equivalent (8–30%), EC (50–82%), SAR (60–85%), exchangeable Na (53–77%), and ESP (46–65%) with cultivation, whereas the amounts of organic carbon (13–130%), total N (27–157%), and exchangeable Ca and Mg (20–60%) were increased after cultivation, indicating the improvement in the soil chemical indicators when converting salt-affected soils to cropland. Soil erodibility factor (K-factor), evaluated based on some physicochemical properties, revealed that 75% of the soils had a decreasing pattern in the K-factor and 25% had an increasing pattern after cultivation. The significant change was not observed in the XRD patterns of the clay fraction by cultivation. Overall, it can conclude that continuous tillage and irrigation-cropping can be a useful method for quality restoration of salt-affected soils in the region.