Impact of Wastewater Spreading on Properties of Tunisian Soil under Arid Climate

The environmental impacts of irrigating an olive field with olive mill wastewater (OMW) and treated wastewater (TWW) on soil properties were investigated. The effect of different irrigation treatments of OMW (50 m(3) ha(-1), 100 m(3) ha(-1), and 200 m(3) ha(-1)) and TWW at different soil depths was studied. The obtained findings revealed that TWW application augmented soil pH; EC values; and P, K and Ca contents in all soil layers. However, Mg and Na concentrations, as well as organic matter content (OM), were proven to decrease with TWW irrigation throughout the experiment. Whereas soil adjusted with OMW showed a decrease in K, Ca, Mg and Na contents with soil depth, a significant increase was observed with the increase in applied OMW dose. On the other hand, total phenols and OM content increased significantly with the rise in OMW levels in all the investigated layers compared to the control sample.

Automated summary

The study investigated the environmental impacts of irrigating an olive field with olive mill wastewater (OMW) and treated wastewater (TWW) on soil properties. The results showed that TWW application increased soil pH, EC values, and certain nutrient contents in all soil layers, while decreasing other nutrient concentrations and organic matter content. On the other hand, soil adjusted with OMW showed varying effects on nutrient contents depending on soil depth and applied dose.