Effect of Inoculation With Two Strains of Rhizobium sp. on the Agronomic Performance of Three Soybean Varieties (Glycine max L.) Cultivated in Mbalmayo, Cameroon

Soybean inoculation with Rhizobium strains is a sustainable and eco-friendly strategy to enhance productivity, particularly in countries where agriculture is hampered by some issues, including acidic soils and the high cost of chemical fertilizers. This study assessed the effect of inoculating three soybean varieties with two Rhizobium strains on nitrogen fixation, plant growth parameters, and productivity. Rhizobium S1 and Rhizobium S2 were used to inoculate seeds of three soybean varieties: TGX 1910 14F, Maksoy 4N, and TGX 1835 10E. The agronomic performance of inoculated soybean seeds was compared with noninoculated seeds over a 120-day field growth period. We found that the total nitrogen content of the var. TGX 1910 14F increased following inoculation with strains S1 (2.93 ± 0.06% vs. 2.53 ± 0.12%) and S2 (3.34 ± 0.05% vs. 2.53 ± 0.12%). A similar trend was observed for the root fresh weight of TGX 1910 14F. Maksoy 4N inoculated with strain S1 exhibited increases in plant height, above-ground biomass, and both fresh and dry root weights. The highest number of nodules was recorded in the inoculated seeds, with strain S2 being the most effective across all soybean varieties. Regarding yield, strain S1 was most efficient for TGX 1910 14F (169.66 ± 75.56 seeds per plant equivalent to 1.35 ± 0.60 tons/ha) and Maksoy 4N (106.0 ± 2.64 seeds per plant equivalent to 0.84 ± 0.02 tons/ha), while strain S2 was most effective for TGX 1835 10E, achieving the highest seeds per plant (174.33 ± 42.91 seeds per plant equivalent to 1.39 ± 0.34 tons/ha). This study presents a practical solution for enhancing the sustainability of farming systems, contributing to the achievement of sustainable development goals, and addressing climate change.