Organic amendment and mycorrhizal inoculation as a practice in afforestation of soils with Pinus halepensis Miller: effect on their microbial activity

Soil amendment with organic materials prior to afforestation as well as the use of mycorrhizal inoculation, are advisable practices in afforestation of semiarid areas. In this work, the effect of both organic amendment and mycorrhizal treatment on the microbial activity of a soil afforested with Aleppo pine (Pinus halepensis Miller) was studied. Labile carbon fractions (water soluble carbon and water soluble carbohydrates), microbiological parameters (microbial biomass carbon, basal respiration and metabolic quotient), and enzyme activities such as oxydoreductases (deshydrogenase and catalase activities) and hydrolases (urease, protease and phosphatase) were determined. All these parameters were found positively influenced by organic amendment and mycorrhizal treatment of plant roots by inoculation of fungi or forest soil addition. The best result was obtained when mycorrhizal inoculation with fungi was supplemented by organic amendment.