An Evaluation of Some Soil Biological Indices in the Presence of Growth-Promoting Rhizobacteria and when Soil Contamination with Cd

Kazemalilou, Solmaz; Rasouli-Sadaghiani, Mir Hosein

doi:10.22059/ijswr.2013.36125

An Evaluation of Some Soil Biological Indices in the Presence of Growth-Promoting Rhizobacteria and when Soil Contamination with Cd

Document Type : Research Paper

Authors

Solmaz Kazemalilou ¹

Mir Hosein Rasouli-Sadaghiani ²

¹ Graduate Student, Soil Science, Department of Soil Science, Urmia University

² Faculty Member, Department of Soil Science, College of Agriculture, Urmia University

10.22059/ijswr.2013.36125

Abstract

Cadmium effects on soil microbial indices and on the interaction of Arbuscular Mycorrhiza Fungi (AMF) and as well on Plant Growth Promoting Rhizobacteria (PGPR) were investigated. The experiments were performed in the framework of a factorial design with levels of cadmium (0, 10, 30 and 100 mg kg^-1 soil), and microbial inoculations (Control, PGPR and AMF) employing Russian Kanapweed as the experimental plant. The experiments were triplicated. The results indicated that soil Cd pollution caused significant decline in plant growth, microbial respiration, Substrate Induced Respiration (SIR), Carbon Availability Index (CAI), Microbial Biomass Carbon (MBC) as well as microbial population. In PGPR and AMF treatments, MBC decreased respectively by 57 and 60% as compared with control (Cd₀). Cd addition significantly increased qCO₂, this index being 22% higher in Cd₁₀₀ as compared with Cd₀. The results indicated that Cd exerts toxic and inhibitory effects on soil microbial activity even at low concentrations. Nonetheless a presence of growth-promoting microorganisms could decline the inhibitory effects of cadmium against plant growth and as well against soil biological activities.

Keywords

arbuscular mycorrhizae

Cadmium

plant growth promoting microorganisms

soil biological properties