Statistics related to Affect of Increase in Bacterial Activity on different crops

I wish to know about how will the Yield of Specific crops like Rice, wheat, Pulses etc. be affected due to the Amount of Bacteria in the Soil. I am Working on a Project related to Increasing the Crop yield in a field and I wish to know how Crop yields get affected due to varying bacteria Conc. in Soil.

For egs. Presence of bacteria in soil helps Pulse growth. Does anyone have any statistics or data supporting it.Similarly for Rice , wheat and other Crops grown in India.