Legume-based intercropping systems promote beneficial rhizobacterial community and crop yield under stressing conditions

Intercropping is an adapted farming system to optimize resource-use efficiency and crop yield, particularly in low input agricultural systems. Due to the beneficial eco-agricultural effects of grain legumes, their integration in mixed cropping systems such as intercropping systems can be more beneficial to soil fertility, soil functioning, and nutrient cycling. About 16-22% of the world's food is provided by cropping systems. On smallholder farms in Eastern and Southern Africa, the integration of legumes has the potential to increase maize (Zea mays) production up to 35% (e.g., Maize-pigeon pea (Cajanus cajan) intercropping). Legume-based intercropping systems can also promote rhizobacterial community diversity and soil health by enhancing symbiotic and non-symbiotic beneficial population. In the rhizosphere, the bacterial community is required to improve the growth and health of both intercrops due to several "direct and indirect" mechanisms involving plant growth-promoting rhizobacteria (PGPR). This review aims to highlight the importance of both legume-based intercropping and root associated microorganisms particular emphasis on rhizobacteria; since the whole "crop-crop-microorganism" system has the potential to improve crop agro-physiological performance. This study also discusses the key role of legumes as intercrops being fully synergistic with PGPR contributing to crop yield stability under stressful conditions, notably drought and nutrient deficiency. Thus, intercropping can be used as an agroecological practice to ensure the sustainability of production.