The Effect of Fruit Trees Pruning Waste Biochar on some Soil Biological Properties under Rhizobox Conditions

The pyrolysis of fruit trees Pruning waste to be converted to biochar with microbial inoculation is a strategy improving the biological properties in calcareous soils. In order to investigate the biochar effect on some soil biological properties of the soil in the presence of microorganisms, a factorial experiment was carried out in a completely randomized design in the rhizobox under greenhouse condition. The factors included organic matter (pruning waste biochar and control), microbial inoculation (arbuscular mycorrhizal fungi and plant growth promoting rhizobacteria) and soil (rhizosphere and non-rhizosphere). After the end of the wheat plant growth period, microbial respiration (BR), Substrate-induced respiration (SIR), microbial biomass carbon (MBC), microbial biomass phosphorus (MBP), acid phosphatase (ACP) and alkaline phosphatase (ALP) enzymes in the rhizosphere soil and non-rhizosphere soil were determined. The results showed that the biochar and microbial inoculation application increased BR, SIR, MBC, MBP and ALP and decreased ACP, as compared to the control. So, the highest increase in the value of BR, SIR and MBC was related to mycorrhizal inoculation with biochar. An increase of 2.67 fold of ACP activity was observed in the treatment of bacterial inoculation with Biochar, as compared to the control treatment. Also, pruning waste biochar increased the amounts of MBC, MBP and ALP by 45.62%, 56.22% and 62.6% in the rhizosphere soil rather than non-rhizosphere soil, respectively. Microbial inoculation led to the increase of 1.31 and 1.41 folds by MBP and ACP in the rhizosphere soil, as compared with non-rhizosphere soil. Bacterial inoculation in the rhizosphere soil increased the ACP enzyme activity (28.31%), as compared with non-rhizosphere soil. It could be concluded that application of biochar in the conditions of microbial inoculation improved the soil biological properties.