Effects of alternate use of wastewater and fresh water on soil saturated hydraulic conductivity

The objective of this research was to study the effects of alternate uses of wastewater with different cycles (one, two and three) and fresh water on the saturated hydraulic conductivity of surface layer (K-s) as relative K-s (K-r1) in sandy loam, loam and clay loam soils. The results showed that the reduction in K-r1 mainly occurred in the surface layer due to the application of wastewater. This effect is more pronounced in clay loam soil than in loam and sandy loam soils, especially with three cycles of wastewater application. The application of fresh water after one and two cycles of wastewater improved the value of K-r1. Improvement of K-r1 by fresh water application after three cycles of wastewater is not pronounced. Therefore, it is recommended to use fresh water after two cycles of wastewater in order to prevent the deterioration of soil K-s. It is concluded that the fresh water application is more effective in sandy loam soil than in loam and clay loam soils in improving the K-r1 reduction due to the wastewater application. The effect of wastewater application on the reduction of K-r in the subsurface layer (K-r2) is less than those obtained for the surface layer. The reductions in K-r2 in the subsurface layer are about half of those obtained on the surface layer (K-r1).