Short Term Influence of Olive Mill Wastewater on Soil Physical and Hydraulic Properties.

Olive mill wastewater (OMW), as a by-product of oil production, has recently gained a great attention as a source of irrigation water on one hand, and to its negative effect on soil, water and environment on the other hand. In this study, we investigated the effect of OMW on selected soil physical and hydraulic properties (aggregate stability (AS), penetration resistance (PR), infiltration rate (IR), hydraulic conductivity (HC), soil moisture content, and water repellency (WR)), as well as soil chemical properties (total polyphenol (TP), organic matter (OM), pH, electrical conductivity (EC)). Silty loam soil was packed into polyvinyl chloride (PVC) columns in three layers (0-8, 8-16, 16-24cm) divided into two groups. The first group (12 columns) was subjected to four wetting and drying cycles; where OMW was added to each column every week at different loading rates (0, 50, 100, and 200 m³ ha^-1). The second group (the remaining 12 columns) was continued to be irrigated for another four wetting and drying cycles.