Evaluation of Some Soil Quality Indices as Influenced by the Intercropping Patterns of Bean and Moldavian Balms, and Microbial Inoculation

Intercropping under microbial inoculation has been suggested as a method to improve the soil quality indices. The objective of this study was to evaluate the effect of microbial inoculation on some soil quality indices of moldavian balms- and bean-planted soils in sole cropping and intercropping. This experiment was carried out in the form of a factorial based on a randomized complete block design with three replications in greenhouse condition. Studied factors were microbial inoculation (AMF, PGPR, AMF+PGPR and without microbial inoculation) and planting patterns (sole cropping of moldavian balms and bean, 1 row moldavian balms + 1 row bean (1:1), 2 row moldavian balms + 2 row bean (2:2), 2 row moldavian balms + 1 row bean (2:1) and 1 row moldavian balms + 2 row bean (1:2)). At the end of the growth period, microbial respiration (BR), substrate-induced respiration (SIR), microbial biomass carbon (MBC), metabolic quotient (qCO2) and carbon availability index (CAI) in moldavian balms- and bean-planted soils were determined. The results showed that the intercropping patterns and microbial inoculation had a significant effect on all soil quality indices, in moldavian balms and bean plantation. The BR and SIR in the 2:1 intercropping moldavian balm under PGPR+AMF inoculation were measured to be 1.21 and 1.17 times higher than those of sole cropping, respectively. The 2:1 intercropping with PGPR+AMF inoculation increased MBC by 1.11 and 1.24 times, as compared to sole cropping of bean- and moldavian balm-planted soils, respectively. Different intercropping patterns and microbial inoculation increased soil CAI and decreased qCO2. In general, the application of intercropping and the potential use of microorganisms could improve the soil quality indices.