Effectiveness of artificial zeolite amendment in improving the physicochemical properties of saline-sodic soils characterised by different clay mineralogies

Abstract

The use of artificial zeolite (AZ) derived from recycled material as a soil amendment has recently received much attention. The effectiveness of AZ in controlling soil loss, sediment concentration, and runoff water quality in artificial sodic soils is discussed in this study. Soils containing 3 different types of clay mineralogies (kaolinitic, smectic, and allophanic) were tested. Aggregate fractions with sizes >2000 μm and saturated hydraulic conductivity were considerably decreased due to aggregate dispersion after soil sodification, although the sodic KS soil was most stable. The addition of 10% AZ to sodic soil improved the mean weight diameter (MWD) and saturated hydraulic conductivity due to a decrease in exchangeable sodium percentage, resulting in a reduction in soil aggregate dispersion. This improvement of sodic soil with AZ had a beneficial effect on erodibility (soil loss and runoff water). This is attributed to the increment in soil infiltration as a result of the suppression of seal formation on the soil surface. The suppression of erodibility effectively controlled the salt concentration of runoff water. A beneficial effect of MWD and AZ contents on sediment concentration was observed, and a negative influence of electrical conductivity. These findings complement the role of AZ in controlling soil erosion.