• Azotobacter is free-living, aerobic, non-symbiotic nitrogen-fixing bacteria and has been found beneficial to a wide array of crops covering cereals (corn, sorghum, wheat, rye, barley, rice) millets, vegetables, tropical grass such as Digitaria, Panicum, Brachiaria, cotton and sugarcane.
• These bacteria utilize atmospheric nitrogen gas for their cell protein synthesis. This cell protein is then mineralised in soil after the death of Azotobacter cells thereby contributing towards the nitrogen availability of the crop plants.
• It is wide spread in soil and plant roots.

Azotobacter chrococcum; Azotobacter paspali; Azotobacter beijerinckii – soil inhabitant

Azotobacter vinelardi – soil and water inhabitants

➢ Triple action of nitrogen fixation, bio-control, and production of plant growth promoting substances; e.g; Seed inoculants in wheat, tomato, rice, brinjal, cabbage, onion enhances yield increases due to the propagation of growth substances, antifungal, antibiotics and fixation of atmospheric nitrogen.

➢ Requires a large amount of organic carbon for its growth but are tolerant to high salts.

➢ Fix 15-20 kg/ha N per year

➢ Also increase germination and vigor in young plants.