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

ABSTRACT:

Erosion is a worrying environmental problem in the Mediterranean basin, and effective systems of soil protection against erosive risks are in great demand. Six herbaceous species commonly used to restore Mediterranean soils (Lolium perenne, L. rigidum, Medicago sativa, Dactylis glomerata, Lotus corniculatus and Cynodon dactylon) were tested for their ability to establish themselves at different soil fertilization levels. Sewage sludge was used as fertilizer at four rates 0% (unfertilized soil), 7%, 15%, and 100% of sludge. Lolium perenne, L. rigidum, and Dactylis glomerata were the most suitable species when sown in non fertilized soils and Cynodon dactylon was the only suitable species when sown in pure sludge. Maximum germination speed and germination rates of all species tested took place in soils fertilized with sludge at 7% and at 15%.