Organic amendment is an important element in agricultural production, given its effects on soil fertility. In this study, a trial was carried out on a plot of barley cultivated with sludge from the Beja wastewater treatment plant. A comparative study was carried out between the physico-chemical parameters of the two plots, unamended and amended with residual sludge (nitrogen, carbon, potassium, phosphorus and trace element content, structural stability and water permeability). Pre-sowing and post-harvest samples were taken. The results obtained showed a more or less significant difference in the physico-chemical parameters of the soil in the study area. For other major and trace element parameters, the difference was small. A significant difference was also recorded for barley yields (Arkansas variety) in the two plots amended and not amended with residual sludge. This work is aimed at correcting soil fertility with organic amendments, but this correction can be made over the long term.