Efficient Rhizobium Spp. Strains in Nitrogen Fixation Enhance the Yield of Phaseolus Vulgaris Var. “panamito” in Acidic Soils

Abstract

Rhizobia, Gram-negative soil bacteria, play a fundamental role in inducing the formation of nitrogen-fixing nodules in the roots of legumes such as Phaseolus vulgaris, an important plant due to its agricultural, economic, and ecological characteristics. This study evaluated the effect of Rhizobium spp. strains on biological nitrogen fixation in P. vulgaris var. “Panamito”. In a field design, seven treatments were compared: five strains of Rhizobium (Rhizobium tropici CIAT899, Rhizobium freirei PRF81, Rhizobium sp. E10, Rhizobium sp. Colombia, and Rhizobium sp. Hg), a nitrogen control (120 kg N/ha), and a non-inoculated control, with five replications each. Vegetative and production parameters were measured. Inoculation with Rhizobium spp. strains was effective in biological nitrogen fixation, with strain E10 achieving a yield of 1,257.50 ± 143.10 kg/ha. This yield was superior to that of the other strains and treatments, exceeding the nitrogen treatment (1,104.83 ± 84.84 kg/ha) by 13.81% and the non-inoculated control (822.31 ± 41.27 kg/ha) by 52.92%. This efficiency is attributed to the origin of the strain and its adaptability to various ecosystems, showing greater infectivity and effectiveness in nitrogen fixation in symbiosis with P. vulgaris var. “Panamito”. Strain E10 is recommended as an inoculant to improve common bean productivity in acidic soils in the San Martín region. This study provides a novel contribution by evaluating specific strains of Rhizobium spp. in acidic and low-fertility soils of Aucaloma, Peru, which could enhance agricultural production and environmental sustainability in legume crops.