Effect of Arbuscular Mycorrhizal Fungi (AMF) and Rhizobium Inoculation on Growth and Yield of Glycine max L. Varieties

Abstract

Biofertilizers are preparations containing living cells that help crop plants in the uptake of nutrients. This study aimed to investigate the effect of coinoculation of arbuscular mycorrhizal fungi and Rhizobium species on the growth and nutrient uptake of three varieties of Glycine max: Belsa 95, Afgat M5, and Nova E3, in the greenhouse and the field. These varieties were obtained from the Gambela research center of Ethiopia. Commercial Rhizobium inoculants were obtained from the Menagesha Biotechnology Institute (MBI), and the previously isolated indigenous AMF inoculants were mass-produced using Sorghum bicolor as a trap plant. Two kilograms of sterilized soil and sand in a 2:1 ratio were used for greenhouse treatments, and 2 m × 3 m plots were used for field treatments. In the greenhouse trials, for all the three varieties was recorded better yield plant−1 in coinoculated treatments with fertilizer application and without fertilizer application, respectively. The highest root number plant−1 (10.0 ± 1.2 and 10.0 ± 1.7) was recorded for variety 1 with the application of only fertilizer and fertilizer + Rhizobium, respectively, and the highest values (8.7 ± 1.9 and 4.7 ± 0.8) were recorded for coinoculated treatments with fertilizer application for varieties 2 and 3, respectively. For sole mycorrhiza-inoculated treatments in the greenhouse was recorded higher dry biomass (16.67% for V1, 42.20% for V2, and 22.18% for V3) as compared with the control. Moreover, for combined inoculation of AMF + Rhizobium and AMF + Rhizobium + fertilizer were recorded 27.01% and 66.99% for V1, 42.20% and 70.33% for V2, and 36.84 and 80.20% for V3, respectively. That means tripartite interactions favor the growth response in association with higher P and N uptake. Finally, it is recommended to apply biofertilizers as the plant-fungi-Rhizobium interactions may have a bigger potential role in maintaining sustainable agriculture with effective environmental resilience.