An Accessible Maize Sheller for the Post-Harvesting Challenges of Small Farmers in Kenya

Abstract

Maize is a critical staple crop in Kenya, yet post-harvest processing remains inefficient for small-scale farmers who cannot afford industrial shelling equipment. Manual shelling is labor-intensive and time-consuming, often taking over nine hours per 100 kg bag of maize. While mechanized stationary shellers are faster, their bulk and immobility force farmers to transport their harvests—incurring costs that consume up to 89% of potential profits. This project developed and tested a low-cost, portable maize sheller tailored to the constraints and priorities of smallholder farmers in rural Kenya. Two prototypes were designed, built, and evaluated. The first achieved high shelling efficiency (97.3%) and processing speeds of 18.9 seconds per kilogram but required manual stabilization of each cob. The second prototype introduced an inner-outer shelling mechanism that enabled hands-free operation and supported continuous feeding. While its average shelling efficiency (89%) fell slightly below the target of 95%, it marked a significant step toward improving usability and throughput. Design decisions were informed by feedback from agricultural experts and field testing with 13 farmers in Migori County, Kenya. User input emphasized portability, ease of use, and minimal post-shelling cleaning. The project demonstrates the viability of an accessible shelling device that could substantially reduce labor, improve efficiency, and enhance profitability for smallholder farmers. With further refinement, this solution could be adapted for broader deployment in similar agricultural contexts.