Effects of sewage sludge on the establishment of the herbaceous ground cover after soil restoration

Erosion is a worrying environmental problem in the Mediterranean basin, and effective systems of soil protection against erosive risks are in great de mand. Six herbaceous species commonly used to restore Mediterranean soils ( Lolium perenne, L. rigidum, Medicago sativa, Dactylis glomerata, Lotus corn iculatus and Cynodon dactylon) were tested for their ability to establish t hemselves at different soil fertilization levels. Sewage sludge was used as fertilizer at four rates 0% (unfertilized soil), 7%, 15%, and 100% of slud ge. Lolium perenne, L. rigidum, and Dactylis glomerata were the most suitab le species when sown in non fertilized soils and Cynodon dactylon was the o nly suitable species when sown in pure sludge. Maximum germination speed an d germination rates of all species tested took place in soils fertilized wi th sludge at 7% and at 15%.