**4. Conclusions and Perspectives**

The properties of three agricultural soils and olive pomace biomass slag (OPBS) were examined in this study to explore the possible use of OPBS as a soil additive and improver. The important findings are summarized in the following points:


Monitoring the soil and water quality in the R'mel area is currently not subject to any regulatory control. Moreover, very little data exists on the quality of groundwater and soil. The nature of the soil and the extent of the water table at a shallow depth make these waters sensitive to pollution by the surrounding agricultural activities. Therefore, it is certain that if nothing changes in the current behavior of farmers in the short term, the R'mel zone will be exposed to significant serious effects. This study intended to explain the main factors affecting groundwater quality in this area as well as propose a low-cost solution allowing the remediation and optimization of soil quality.

**Author Contributions:** Conceptualization, O.S. and F.E.M.; methodology, O.S.; software, O.S.; validation, O.S., F.E.M. and M.S.; formal analysis, J.B.; investigation, O.S.; resources, F.E.M., E.O. and J.M.; writing—original draft preparation, O.S. and F.E.M.; writing—review and editing, E.O., A.O., J.M. and F.E.M.; visualization, J.B.; supervision, M.S. and A.O.; project administration, M.S. and J.B.; All authors have read and agreed to the published version of the manuscript.

**Funding:** This research received no external funding.

**Institutional Review Board Statement:** Not applicable.

**Informed Consent Statement:** Not applicable.

**Data Availability Statement:** Not applicable.

**Acknowledgments:** The authors are thankful to Shimadzu and Merck Life Science Corporations for their continuous support.

**Conflicts of Interest:** The authors declare no conflict of interest.
