Harnessing energy, nutrients and water from agricultural waste

Worldwide, millions of tonnes of waste is produced each day, including agricultural waste such as maize cobs, millet husks, groundnut shells and animal manure. Used water from industrial and household sources also classifies as waste. However, the safe management and use of such waste can allow farmers to derive value from it.

Resource Recovery from Waste, Business Models for Energy, Nutrient and Water Reuse in Low- and Middle-income Countries stresses how the recycling of waste products can support livelihoods and green economies in low- and middle-income countries. In the publication, emphasis is placed on agro-industrial waste (such as slaughterhouse refuse), food waste and household waste (including sewage) and the ways in which they can be transformed in order to maximise resource recovery. 

Striking infographics and diagrams provide examples of how waste can be repurposed, for example, using rice husks to produce electrical power or transforming sewage into nutrient rich compost. Properly treated waste water can also be used in irrigation and in replenishing reduced ground water levels in drought-affected areas. 

There are 24 examples of effective waste recovery within this publication and 15 case studies from Africa, which emphasise the value of repurposed waste. The World Economic Forum estimates that the potential global revenue for biomass from agricultural inputs could reach as high as €250 billion by 2020. The empirical evidence of these studies shows how energy, nutrients and water from waste can be reused to ensure that refuse does not amount to lost value for farmers in less economically developed nations. 

Alex Miller

The Technical Centre for Agricultural and Rural Cooperation (CTA) is a joint international institution of the African, Caribbean and Pacific (ACP) Group of States and the European Union (EU). CTA operates under the framework of the Cotonou Agreement and is funded by the EU.