Effects of Contour Ridge Benches on Several Physical and Chemical Soil Characteristics at the El Ghrifettes Site (Zaghouan, Tunisia)

The present study investigates the effects of contour ridge benches (CRBs) on several physical and chemical characteristics, such as soil depth, texture, rock fragments, organic matter, calcium carbonate (CaCO3), pH, and water content. The study site is located at an old contour ridge bench in the Tunisian Dorsal. Soil samples were collected at different relative positions of two successive CRBs and from a control plot having the same slope, land use, and soil. The results indicated that the CRB improved soil depth from 40 cm in the control plot to 90 cm near the upper side of the CRB. The highest rock fragment was found in the control plot. The soil texture had significant differences according to the sampling depth and proximity to the CRB. Although the CaCO3, total and active, depends on the sampling depth, it was slightly higher in the control plot. Considering the calcareous nature of the soil, pH and electric conductivity were not affected by relative position to the CRB. The organic matter was less...