Improvement of tree growth in salt-affected soils under greenhouse conditions using a combination of peanut shells and microbial inoculation

This study aimed at selecting an effective microbial inoculum to enhance the performance of Senegalia senegal, Vachellia seyal and Prosopis juliflora and assessing the combination effect of microbial inoculation and peanut shells amendment on their growth under salinity in greenhouse conditions. In the first experiment, seedlings were individually cultivated in plastic bags containing non-sterile sandy soil. Seedlings were inoculated at transplantation with rhizobial and arbuscular mycorrhizal fungi (AMF) strains. Four inoculation treatments were performed: control, inoculation with rhizobia, inoculation with AMF and dual-inoculation with rhizobia and AMF. After one month, seedlings were gradually watered with four saline solutions (0, 86, 171 and 257 mM NaCl) for 4 months. ANOVA showed that inoculation treatments significantly increased seedlings growth particularly in saline conditions and the best performance was obtained with dual inoculation. In the second experiment, seedlings were grown under the same experimental conditions on a mixture of non-sterile sandy soil and 6 tha-1 (169.56 g per bag) of peanut shells var 73-33. Results showed that inoculation, peanut shells and their combination significantly improved seedlings growth. The higher performance was obtained with the combination of microbial inoculation and peanut shells.