The forms an inoculant comes in — and how the world uses them
Peat, liquid, granule, or on the seed — the form a live inoculant takes decides how it stores, how it goes on, and how many bacteria reach the root. A guide to the formats, our own range, and how usage differs from Brazil to Australia to Africa.
An inoculant is living bacteria, so — unlike a chemical — it cannot simply be poured from a jug and forgotten. The bacteria have to be carried, sheltered from heat, sun, and drying, from the factory all the way to the root, and the “form” a product takes is that carrier. The form is not a packaging detail: it sets how long the product lasts, how it goes on, whether it survives contact with seed treatments, and ultimately how many live cells reach the seedling. This guide walks through the main forms, our own range, and how growers around the world choose between them.
The main forms
Almost every legume inoculant on the market is a variation on four forms. They differ in cost, convenience, the dose they deliver, and how well they protect the bacteria — and each suits some situations better than others.
The main inoculant forms
| Form | What it is | Strengths | Watch-outs |
|---|---|---|---|
| Peat / powder | Freeze-dried rhizobia in sterilised peat, slurried onto seed | Low cost, proven, protects cells well | Sensitive to heat and UV; sow promptly |
| Liquid | Live bacteria in a nutrient carrier, on seed or in-furrow | Easy, even coverage, standard equipment | Shorter shelf life; often needs cool storage |
| Granular | Bacteria in a clay or polymer prill, dropped in the furrow | Highest dose; avoids seed chemistry; resists drying | Costs more; needs a granule box |
| Seed-coat / pre-inoculated | Applied and encapsulated on seed commercially | Convenient; longer on-seed shelf life | Check the date; re-inoculate old seed |
The pattern is that the cheaper, seed-applied forms (peat and liquid) are fine in easy conditions, while granular in-furrow trades cost for a bigger dose and a way around hostile seed coatings — which is why it is the safer choice on treated seed and on tough or first-time ground.
Our own range
Our products come in the same family of forms, so you can match the format to your planter rather than the other way round. Every one is guaranteed to a live count of at least 10⁹ CFU per gram or millilitre to expiry, built on spore-forming strains for real heat and desiccation tolerance, with a 12–24 month shelf life.
Our formats, and their rates
| Format | Form | Rate |
|---|---|---|
| Ground | Granule (2–4 mm) | 60 kg/ha, broadcast or banded |
| Precision | Microgranule | 5–10 kg/ha, bulk-blend |
| Flow | Liquid | 1–3 L/ha, in-furrow |
| Seed | Peat seed inoculant | 3–5 g/kg seed |
| Coat | Liquid seed coat | 2–4 mL/kg seed |
Whatever the form, the handling rules are the same: keep it cool and out of the sun, apply at sowing close to the seed, add it last after any fungicide seed treatment, and use it before the date on the bag.
How the world uses them
Which form dominates has as much to do with geography, climate, and market maturity as with agronomy. A quick tour:
Common inoculant forms by region
| Region | Mainstay | Notes |
|---|---|---|
| Brazil & Argentina | Peat, increasingly liquid | Among the world’s largest soybean-inoculant markets; peat carriers established in Brazil since the late 1990s, now moving to liquid and industrial on-seed treatment |
| North America & Europe | Liquid, commercial seed treatment | Liquid widely available; a strong shift to professionally-applied seed treatment |
| Australia | Peat slurry, plus liquid and granule | Finely-milled, sterilised peat on seed is the mainstay for grain legumes; liquid is routine on soybean and winter pulses; granules where a harsh seed fungicide is used |
| Sub-Saharan Africa & South Asia | Peat | Low-cost peat dominates, but weak cold chains and hot storage make survival — and adoption — harder; robust handling matters most here |
The through-line is that hotter climates and weaker cold chains put a premium on formulation robustness — spore-forming strains, protective carriers, and forms that resist heat and drying — which is exactly what we design for.
Which form should you choose?
Start from your seed and your planter. If the seed is treated with a fungicide, or the ground is new or stressful, reach for a granular in-furrow form that carries a big dose and never touches the coating. If you want the simplest, lowest-cost route on clean seed, peat or liquid on the seed does the job. High-throughput mechanised farms often prefer liquid or microgranule for even, fast application; pre-inoculated seed is the most convenient, as long as you check the date. The form changes; the goal never does — living bacteria, in enough numbers, delivered to the root at sowing.
In short: peat, liquid, granule, and seed-coat each trade cost, dose, and convenience differently, and the right one depends on your seed, your planter, and your climate. Whatever you choose, the same handling rules decide whether the bacteria arrive alive.