Rhizospheric Study of Pruning Wastes Compost Effect in the Presence of Growth Promoting Bacteria on some Soil Quality Indices

The objective of this research was to evaluate the effect of pruning waste compost and plant growth promoting rhizobacteria (PGPR) on some biological properties of calcareous soil, A factorial experiment was carried out in a completely randomized design under greenhouse condition in rhizobox. The factors were as the organic matter (compost, pruning wastes and without organic matter), microbial inoculation (PGPR and no inoculation) and soil (rhizosphere and non-rhizosphere soils). At the end of the growth period of wheat, microbial biomass carbon, microbial biomass phosphorus, microbial respiration, substrate-induced respiration and alkaline phosphatase in the rhizosphere and non-rhizosphere soils were determined. The results showed that the application of compost and inoculation of PGPR significantly increased the microbial biomass carbon, microbial biomass phosphorus and alkaline phosphatase activity compared to non-inoculated treatment. Furthermore, compost treatment increased the microbial biomass carbon, microbial biomass phosphorus and alkaline phosphatase activity in the rhizosphere soil by 1.23, 1.59 and 1.05 times compared to those in the non-rhizosphere soil, respectively. Microbial respiration and substrate-induced respiration in the rhizosphere soil of pruning wastes treatment were 10.55 and 2.23 times higher than those in the non-rhizosphere soil, respectively. It was concluded that application of organic matters and microbial inoculation caused to improvement in soil quality indices.