VERMICULTURE AND VERMICOMPOSTING: TWIN EARTHWORM TECHNOLOGIES, SUITABLE FOR HOUSEHOLDS AND SMALLHOLDER FARMERS TO CONVERT WASTES TO WEALTH – A NARRATIVE REVIEW

Abstract

Many smallholder farmers in developing countries face interconnected challenges, including poor soil fertilisation, low agricultural output, and inefficient conversion of agricultural wastes into biofertilisers, all of which can be sustainably addressed through vermiculture and vermicomposting—twin earthworm-based technologies. This review aims to explore vermiculture and vermicomposting, their interconnections, and key optimisation factors, while also guiding smallholder farmers on setting up simple vermiculture and vermicomposting units using locally sourced materials. A wide literature search was conducted across databases such as Google Scholar, Scopus, and Web of Science, focusing on vermiculture, vermicomposting and earthworm utilisation in waste management. From an initial pool of articles, 35 studies were selected for their relevance, empirical data, and rigorous methodology. Findings show that earthworms' natural behaviours, such as burrowing, soil ingestion, excretion and rapid reproduction, are exploited by vermiculture and vermicomposting to produce both earthworm mass and vermicompost, a sustainable and efficient biofertilizer. Vermiculture focuses on maximising earthworm harvest, with vermicompost as a secondary product, while vermicomposting aims to maximise vermicompost production, often resulting in increased earthworm mass. Vermicomposting units can be constructed from locally available materials, including wood, organic and agricultural wastes, and earthworm food sources, like fermented cow and sheep dung. The review assesses the potential of these technologies for small-scale farms, emphasising their feasibility and benefits in resource-limited settings. Since low agricultural output by smallholder farmers is partly traceable to unaffordable costs of chemical fertilisers, this review will draw attention to the use of vermicompost as a cheap and sustainable alternative