Microbial Inoculation Improves Soil Properties, Nutrient Uptake, and Plant Growth in Soft Wheat-Faba Bean Intercropping

A pot experiment was conducted to evaluate the effects of inoculation with arbuscular mycorrhizal fungi (AMF) and plant growth–promoting rhizobacteria (PGPR) on mycorrhizal colonization, soil properties, and soft wheat (Triticum aestivum (L.)) and faba bean (Vicia faba (L.)) growth in monoculture and intercropping systems. Four treatments were arranged in a split-plot design: (i) uninoculated plants, (ii) PGPR-inoculated plants, (iii) AMF-inoculated plants, and (iv) PGPR-AMF co-inoculated plants. The findings showed that intercropping along with PGPR-AMF co-inoculation improved mycorrhizal colonization, soil properties, and plant growth. This system enhanced the mycorrhizal frequency (88.00–96.00%) and intensity (53.94–71.74%) in both species as compared to their respective monocultures. The contents of soil nitrogen, phosphorus, and potassium increased by up to 50.65%, 55.81%, and 44.05%, respectively compared to monocultures. This resulted in increased nutrient availability, which in turn increased the mineral content in plants (N, 52.55–60.01 mg g−1 dry weight (DW); P, 3.87–4.40 mg g−1 DW; K, 47.78–52.05 mg g−1 DW). Combining intercropping and co-inoculation promoted shoot growth (55.17 cm in soft wheat and 65.83 cm in faba bean) and increased dry matter yield. This system also increased the contents of protein, chlorophyll, and sugar by 23.91%, 35.00%, and 34.75% in soft wheat, and by 70.05%, 26.00%, and 30.25% in faba bean, respectively compared to their respective monocultures. The findings of this study revealed the beneficial effects of co-inoculation and intercropping on soil fertility and plant growth, and suggest the use of this system as a sustainable approach to improve crop productivity and promote food security.