Improving the fertility of degraded soils from a limestone quarry with organic and inorganic amendments to support vegetation restoration with semiarid Mediterranean plants

The restoration of highly disturbed soils like those in abandoned quarries is a particularly difficult task in semiarid Mediterranean areas because of limitations in soil fertility and water availability. The addition of inorganic and organic amendments together with the selection of native plants is a key factor for success in edaphic and ecological soil restoration. The current study addresses the increase in the fertility of a semiarid bare soil from a quarry and the growth and survival of several native plant species (Olea europaea var. Sylvestris, Pistacia lentiscus, Rosmarinus officinalis, Quercus coccifera) through the addition of organic (compost derived from horticultural crop residues and poultry manure) and inorganic (three types of zeolites: mordenite clinoptilolite, and ZeoPro) amendments. Several combinations of the amendments (compost (C), zeolite ZeoPro (Z), mordenite zeolite plus compost (MZ + C), clinoptilolite zeolite plus compost (CZ + C), and clinoptilolite zeolite plus poultry manure (CZ + PM)) of different doses (5%, 10 %, 20 %, 30 %) were analyzed. Most of the doses in all treatments increased the fertility of the soils (measured by macronutrients and organic matter content) to guarantee optimal rates of growth and survival of the different plant species, although clinoptilolite zeolite and compost were the more successful treatments for the plants' development. These results are of great interest in the understanding of the interactions between physico-chemical soil parameters and plant performance in soil restoration.