Introduction Soil is a life supporting system, a natural and a vital resource for growing food, fibre and firewood to meet the human needs. The importance of soil biota was realized by the agricultural scientist and farmers recently. Since, Hiltner defined rhizosphere in 1904 some remarkable advances have been made in recognition of the important role of microorganisms (and to some extent micro fauna) in the rhizosphere soil. According to Arshad and Frankenberger [1] rhizosphere is the portion of the soil under the direct influence of the roots of higher plants. It is considered the most intense ecological habitat in soil in which microorganisms are in direct contact with plant and it is associated with a distinct, diverse community of metabolically active soil microbiota that carry out biochemical transformations.