Two of the creative minds have found novel ways of making the invasive water hyacinth useful, to the point where it can be fed to livestock or where its stems can be fermented to generate liquid fuel.
Another one has discovered how rice husks and other unwanted plant products can be converted into top-notch fertiliser.
One has developed a way of creating large solar-powered freezers whose space can be leased out to those who deal in meat and other perishable products in the remote parts of Kenya.
Jack Oyugi, Richard Arwa, Samuel Rigu and Tracy Oyugi – are battling it out with 11 other Africans from Ghana, Malawi, Nigeria, South Africa and Uganda for the top prize of £25,000 (Sh3.3 million) from the organisers.
Read more: Daily Nation