Rhizobial Science

Accordingly, Nodu™ strains are selected and matched to local conditions (not one global strain), and Orvan™ contains no rhizobia — it amplifies the native or co-applied rhizobia already adapted to each region, fitting local soils rather than imposing a single strain.

Cross-inoculation groups — match by group, then by region

Legumes fall into cross-inoculation groups defined by the rhizobia that can nodulate them. Matching the right group first — then confirming the right strain for local soils — is what makes inoculation reliable.

• Soybean-specific Bradyrhizobium (Soybean): Soybean needs Bradyrhizobium japonicum / diazoefficiens (USDA 110-type) — the general tropical group will not nodulate it effectively, so a dedicated strain is essential.
• Fast-growing Rhizobium (bean) (Common bean): Common bean is nodulated by fast-growing Rhizobium — R. tropici / etli / phaseoli. R. tropici (CIAT 899-type) is acid-, heat-, and aluminium-tolerant and our most mature line.
• Cowpea-miscellany Bradyrhizobium (Peanut · cowpea · mung bean · black gram · pigeon pea): These tropical legumes are promiscuously nodulated by slow-growing Bradyrhizobium of the cowpea-miscellany group; effective strains still differ by region.
• Sinorhizobium (Ensifer) meliloti — alfalfa group (Alfalfa · medics): The alfalfa cross-inoculation group — Medicago, Melilotus and Trigonella — is nodulated by fast-growing Sinorhizobium (Ensifer) meliloti, with the closely related S. medicae on annual medics in acid soils. Distinct from the Bradyrhizobium and Rhizobium groups, S. meliloti thrives above pH 6 but is often sparse in first-time or strongly alkaline-saline fields, so inoculation pays off.