Biofertilizers and Organic Amendments for Enhancing Seedling Vigour in Leguminous Crops: A Review

Abstract

Seedling vigour is an important trait for crop establishment, productivity and resilience in legume crops. Application of biofertilizers and organic amendments has been found as a sustainable approach to improve early seedling growth, germination rate and plant performance. This review summarises the recent findings on the effects of biofertilizers such as Rhizobium, Bradyrhizobium, arbuscular mycorrhizal fungi (AMF), phosphate-solubilizing bacteria (PSB) and plant growth promoting rhizobacteria (PGPR) and organic amendments like vermicompost, farmyard manure, biochar and humic acid on leguminous crop seedling vigour. Evidence indicates that the combined application of biofertilizers and organic amendments has synergistic effects that significantly improve the percentage of germination, length of seedlings, root development, vigour indices and biomass accumulation. These improvements are achieved through mechanisms of increased availability of nutrients, phytohormone production, improved soil structure, and colonisation by beneficial microbes. However, further investigation is needed on challenges such as dose optimisation, environmental variability and species-specific responses. This review emphasises the potential of integrated bio-organic strategies for sustainable legume production and identifies important knowledge gaps and future research directions.