The nutrient status of soil is more essential for root nodulation. The Soybean soil samples were collected from 30 different locations of the semiarid tropics viz., Salem, Namakkal and Dharmapuri belonged to 3 textural groups viz., Red loam, Clay loam and Black soils. The soil samples were analysed for it’s Soil pH, Electrical conductivity, soil organic carbon available N, P and K content. The nodulation pattern and it’s rhizobial populations on the rhizosphere soil of soybean plants were also studied. The nodulation pattern was ranged from 5.00 to 21.00 plant1. Native rhizobial populations were also estimated for the 30 locations of the above mentioned Districts of semiarid tropics of Tamil Nadu. Among the 30 locations, 13 locations recorded more than 3x103g-1.
