Describe the role of Rhizobium in replenishing soil
Since plants cannot absorb nitrogen from the atmosphere. Rhizobium is a symbiotic bacteria present in the root nodules of leguminous plants . The bacteria helps the plant to fix the atmospheric nitrogen and convert it into useable form - ammonia. The ammonia so formed is oxidised first into nitrate and then to nitrates with the help of other soil bacteria by the process of nitrification. The nitrates and nitrites thus formed enrich the soil with useable form of nitrogen that is easily assimilated by the plants..