Agricultural byproduct‐based organomineral fertilizers as alternative nutrient sources for crop production: A review

This review explores how organomineral fertilizers (OMFs)—produced by combining manure and crop residues with mineral fertilizers—are formulated, what they contain, and how effectively they perform. It outlines the contributions of OMFs to increasing crop productivity, improving soil fertility, and reducing climate change impacts. Although OMFs show considerable promise, their adoption remains limited due to issues of accessibility, economic uncertainty at the farm level and amid ongoing global challenges, and weak integration into current farming systems. This paper synthesizes existing research, identifies key knowledge gaps, and proposes future research directions aimed at optimizing agricultural waste materials for use in OMF formulations that support sustainable production systems. Reviewed papers demonstrate that OMF can enhance soil nutrient availability, improve soil organic matter content, reduce greenhouse gas release, and increase microbial activity and moisture retention. In many cases these improvements were shown to maintain or improve crop yield and quality relative to mineral‐only fertilizers (MOF) and may have been greater were studies longer than 1–2 years in duration. Key knowledge gaps remain; reduced greenhouse gas emissions and heavy metal accumulation were measured in relatively few studies and require further scrutiny. Realizing the potential of OMF will require long‐term research that draws on expertise from agronomy, biology, engineering, marketing, and economics to develop reliable agricultural biproduct‐based OMF products compared with MOF. Evaluation protocols suggested in this review would document OMF's performance and guide safe, effective, and profitable adaptation for use in agricultural systems.