Azospirillum (nitrogen-fixing biofertiliser)
The root-associating nitrogen fixer for cereals and grasses — a natural fit for rice, wheat, maize and sugarcane.
- What it is
- Associative N-fixing bacteria
- Form
- Carrier-based / liquid inoculant
- Price
- Low (a few tens of ₹ per acre)
- Best for
- Rice, wheat, maize, sugarcane
Overview
Azospirillum is an associative nitrogen-fixing bacterium: it lives on and just inside the roots of grasses and cereals — rice, wheat, maize, sorghum, bajra, sugarcane — rather than in nodules. There it fixes atmospheric nitrogen and, notably, produces hormones that stimulate a denser, deeper root system, which itself helps the crop take up more water and nutrients.
For cereal and grass crops it is often the biofertiliser of choice, used as a seed treatment or seedling root dip. Like all inoculants it is a supplement that trims the nitrogen dose and improves rooting, not a replacement for the crop’s fertiliser.
What it is and when to reach for it
- An associative nitrogen fixer for cereals and grasses — reach for it on rice, wheat, maize, sorghum and sugarcane.
- It boosts root growth as much as it fixes nitrogen, which improves water and nutrient uptake.
- It supplements the nitrogen plan and is especially handy for transplanted crops as a root dip.
How to use it well
- Seed treatment: coat the seed with an inoculant slurry, dry in the shade and sow the same day.
- Seedling root dip (rice, vegetables): soak the roots of transplants in a suspension before planting.
- Soil: mix the dose with FYM or compost and apply; keep the soil moist for the bacteria to establish.
What it can and cannot do
- A living product — store cool and shaded, keep away from fungicides and agrochemicals, and use before expiry.
- Its nitrogen contribution is modest; the root-growth boost is often the more visible benefit.
- It suits grasses and cereals — for legumes, Rhizobium is the right partner instead.
Common mistakes
- Treating it as a full nitrogen replacement — the fixation is a supplement, not the whole dose.
- Mixing it with a fungicide or agrochemical, which kills the culture.
- Letting the treated seed or the field dry out, so the bacteria fail to establish.
Crops it is used on
Open a crop for its full nutrient schedule.
Common questions
Which crops is Azospirillum used for?
Cereals and grasses — rice, wheat, maize, sorghum, bajra and sugarcane. It associates with their roots to fix nitrogen and stimulate rooting. Legumes use Rhizobium instead; other non-legumes can use Azotobacter.
Azospirillum or Azotobacter — which should I use?
Both are for non-legumes, but Azospirillum specifically associates with the roots of cereals and grasses (rice, wheat, maize, sugarcane) and is usually preferred for them, partly for its strong root-growth effect. Azotobacter is a free-living fixer used more broadly across cereals and vegetables. Either supplements, rather than replaces, nitrogen fertiliser.
How is Azospirillum applied to rice?
Commonly as a seedling root dip: soak the roots of the rice seedlings in a suspension of the inoculant before transplanting. It can also be used as a seed treatment for direct-sown cereals or mixed into FYM and applied to the soil.
Composition and doses follow ICAR / Soil Health Card guidance; prices are the notified subsidised rates for the season shown and are guidance, not a quote. A soil test for your field always beats a general rate. See our editorial policy.