Synergistic influence of an arbuscular mycorrhizal fungus and organic amendment on Pistacia lentiscus L. seedlings afforested in a degraded semiarid soil

A field experiment was undertaken to evaluate the effect of mycorrhizal inoculation with Glomus intraradices and added composted residue on the establishment of Pistacia lentiscus L. seedlings in a semiarid area. Composted residue greatly increased macronutrient (NPK) content, soil microbial activity and enzymatic activities, and decreased soil bulk density. There was a significant correlation between soil bulk density and both enzyme activities and labile C fractions (water-soluble C and water-soluble carbohydrates), which are also related to soil microbial activity. The most suitable methodology for revegetating with P. lentiscus seedlings was addition of composted residue to soil in conjunction with a mycorrhizal inoculation pretreatment of seedlings in a nursery, to increase available P uptake from composted residue. One year after planting, such a combined treatment had increased the plant height of P. lentiscus seedlings by 106% with respect to the control.