Asian Journal of Agricultural and Horticultural Research

Horticultural production is increasingly required to deliver high yields and premium quality while reducing dependence on mineral fertilisers, improving soil function and maintaining resilience under salinity, drought, heat and nutrient stress. Biofertilisers and organic inputs are frequently proposed as complementary tools, yet the evidence is fragmented across microbial inoculants, composts, vermicomposts, digestates, biochar, humic substances, seaweed extracts and protein hydrolysates. This critical narrative review evaluates recent advances in these input classes, the mechanisms through which they may influence horticultural crops, the consistency of agronomic and quality responses, and the constraints that limit translation from controlled experiments to commercial production. Literature published from 1 January 2000 to 31 May 2026 was identified through accessible scholarly indexes, metadata services and citation searching, with foundational sources included when necessary. The evidence indicates that microbial inoculants can improve nutrient acquisition, root development and stress tolerance, while mature organic amendments can enhance nutrient buffering, aggregation, water retention and biological activity. Nevertheless, average benefits conceal substantial context dependence. Outcomes are strongly conditioned by crop genotype, soil or substrate properties, resident microbiota, nutrient status, inoculant viability, amendment maturity, application method and environmental stress. Many positive reports derive from short-duration, single-site experiments with weak nutrient-equivalent controls, incomplete product characterisation or limited assessment of persistence and economics. Stronger evidence supports integrated use that supplements, rather than indiscriminately replaces, mineral nutrition and that matches products to diagnosed soil, substrate and crop constraints. Future progress depends on multi-location factorial trials, standardised product identity and quality testing, mechanistic measurements linked to marketable yield and quality, long-term safety and environmental assessment, and transparent economic evaluation. Biofertilisers and organic inputs therefore have credible roles in sustainable horticulture, but reliable performance requires context-specific design, quality assurance and evidence-based integration into nutrient and crop-management programmes.