Living Phosphorous Biofertilizers: Integrating Biochar–Microbial Engineering, Agricultural Extension and Farmer Adoption for Sustainable Phosphorus Management

Abstract

Phosphorus deficiency remains a major constraint to crop production, while dependence on mineral phosphorus fertilizers is increasingly challenged by low nutrient-recovery efficiency, price volatility, geographically concentrated phosphate resources and environmental losses. This review develops the concept of living phosphorus biofertilizers as an integrated nutrient-management platform that combines functional biochar, phosphorus-mobilizing microorganisms and plant–soil interactions. A structured literature search covered major scientific databases and authoritative institutional sources from 2010-2025, with earlier seminal studies included where necessary. Evidence indicates that biochar can retain phosphorus, modify soil chemical conditions and provide protected microsites for microbial colonization, whereas phosphate-solubilizing bacteria, fungi and mycorrhizal associations can mobilize mineral and organic phosphorus pools. Selected laboratory, greenhouse and field studies support the potential of combined biochar–microbial systems, but the fully integrated living phosphorus biofertilizer remains a proposed framework that requires multi-location and multi-season validation. The review therefore extends beyond technical performance to examine commercialization, product quality, farmer risk perceptions, extension communication, participatory trials, digital decision support, gender and social inclusion, and public–private delivery models. A science-to-farm framework is proposed in which formulation, regulation, demonstration, advisory support and farmer feedback operate as a continuous learning cycle. Living phosphorus biofertilizers could complement rather than immediately replace mineral fertilizers, provided that field efficacy, product consistency, economic feasibility and locally adapted extension recommendations are established.