A quiet agricultural revolution is underway across central Kenya as smallholder farmers increasingly embrace vermiculture—the systematic cultivation of earthworms—to transform their soil health and generate additional income. These farmers are establishing small-scale worm farms where species like the African nightcrawler (Eudrilus eugeniae) and red wiggler (Eisenia fetida) consume organic waste to produce nutrient-rich vermicompost and liquid fertilizer. The practice, once limited to experimental stations, is now spreading rapidly through farmer-to-farmer networks as evidence mounts of its remarkable impact on crop yields, particularly for high-value vegetables, fruits, and tea.
The biological processes behind vermiculture deliver multiple benefits that synthetic fertilizers cannot match. As earthworms digest agricultural waste—everything from crop residues to kitchen scraps and livestock manure—they create a stable humus containing beneficial microorganisms, plant growth hormones, and nutrients in forms readily available to plants. Field trials across Kenya’s central highlands have demonstrated that application of vermicompost can increase maize yields by 20-30% and vegetable yields by up to 50% compared to conventional compost. Perhaps more importantly, the practice improves soil structure, enhancing water retention in drought-prone areas and reducing erosion on sloping lands. Farmers also report significant reductions in pest and disease pressure, likely due to the enhanced microbial diversity the worms introduce to the soil.
The long-term sustainability of this practice lies in its circular economy model and income diversification potential. Farmers are not only producing vermicompost for their own use but are creating small businesses selling both worms and castings to neighboring farms. A single farmer with a modest 4×6 meter worm bed can generate additional annual income of KSh 50,000-80,000 ($350-550) while simultaneously reducing their expenditure on chemical fertilizers. Agricultural training centers are now incorporating vermiculture into their curriculum, and the Ministry of Agriculture is promoting it as a cornerstone of climate-smart agriculture. As Kenya confronts the dual challenges of soil degradation and climate uncertainty, this nature-based solution demonstrates how working with soil biology rather than against it can build agricultural resilience while creating economic opportunities for rural communities.