KMB — Potash-Mobilising Bacteria
The biofertiliser for potassium — microbes that free up the potash bound in soil minerals so the crop can use more of it.
- What it is
- Potash-mobilising bacteria
- Form
- Carrier-based / liquid inoculant
- Price
- Low (a few tens of ₹ per acre)
- Best for
- Unlocking soil potassium
Overview
Indian soils often hold a large amount of potassium locked in mineral form that plants cannot directly use. KMB — potash-mobilising bacteria (such as Frateuria aurantia) — release organic acids that weather these minerals and free potassium into the available pool, and they help make applied potash go further too.
It is the newest of the common biofertilisers and, like PSB for phosphorus, is a mobiliser rather than a source: it unlocks the soil’s own potassium reserve, so it can trim the potash dose on potassium-hungry crops like potato, sugarcane and banana. It complements MOP rather than replacing it, and pairs well with PSB and a nitrogen inoculant.
What it is and when to reach for it
- A potassium-unlocking biofertiliser — reach for it on potassium-hungry crops (potato, sugarcane, banana) to get more from the soil’s potassium reserve.
- It pairs naturally with PSB (phosphorus) and a nitrogen inoculant to cover all three nutrients biologically.
- It is a mobiliser, not a potassium source, so it trims the potash dose rather than removing it.
How to use it well
- Seed treatment: coat seed with an inoculant slurry, dry in the shade and sow the same day — often with PSB and a nitrogen inoculant.
- Soil: mix the dose with FYM or compost and broadcast; keep the soil moist so the bacteria establish.
- For transplanted crops, a root dip in a suspension works well.
What it can and cannot do
- A living product — store cool and shaded, keep away from agrochemicals, and use before expiry.
- It mobilises existing soil potassium; it does not add potassium, so a genuinely potassium-poor soil still needs MOP or SOP.
- Its benefit is largest on soils with a good mineral potassium reserve that is simply not available to the crop.
Common mistakes
- Expecting it to replace MOP on a potassium-poor soil — it unlocks potassium, it does not create it.
- Mixing it with a fungicide or agrochemical, which kills the bacteria.
- Storing it in heat or using it past expiry, so few live organisms remain.
Crops it is used on
Open a crop for its full nutrient schedule.
Common questions
What does KMB (potash-mobilising bacteria) do?
It releases organic acids that weather potassium-bearing soil minerals and free that potassium into a form crops can take up, and it helps applied potash go further. In effect it unlocks the soil’s own potassium reserve, improving potash-use efficiency.
Can KMB replace MOP?
No — it mobilises existing soil potassium but adds none of its own. On a potassium-poor soil you still need MOP or SOP; KMB then helps you get more from a smaller dose. Its benefit is largest where the soil has plenty of mineral potassium that is simply unavailable.
Can I use KMB with PSB and nitrogen biofertilisers?
Yes — the three are commonly used together: a nitrogen inoculant (Rhizobium or Azotobacter/Azospirillum), PSB for phosphorus and KMB for potassium, covering all three biologically. Keep the whole combination away from fungicides and agrochemicals.
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.