Rhizobium (rhizobia), inoculant 
Soil bacteria that form nodules on legume roots.
Characteristics
- Each legume needs its own rhizobium species; sensitive to heat, drying and light (NMSU, 2015).
- One of the four groups of micro-organisms admitted as microbial biostimulants by Regulation (EU) 2019/1009.
Role in the preparation: Commercial inoculant (peat or granules) to coat legume seeds before sowing.
Caution: Buy an identified inoculant and store it as the label says; wear gloves and a mask when handling powders; check local regulations before any use.
Sources: New Mexico State University, Cooperative Extension (rév. 2015) – Inoculation of Legumes, guide A-130 · EUR-Lex – Règlement (UE) 2019/1009, produits fertilisants UE (annexe II, CMC 7 : biostimulants microbiens)
Documentary information: this is neither a recommendation for use nor a plant-protection or veterinary claim. Check your country's regulations before any use.