Nutrient recovery from solid waste and linkage to urban and peri-urban agriculture in Nairobi, Kenya

Abstract

Community based composting practices were studied in Nairobi using a questionnaire, and the quality of composts produced characterised for nutrient and heavy metal contents. An inventory of the composting groups was made using existing databases. The quality of different manure types and their sources were also noted. The movement of Municipal Solid Waste (MSW) for composting and its outlets, as well as manures, were investigated through mapping of market and ecological chains. The study objectives aimed at documenting group dynamics in community based composting activities, quality of composts as influenced by different composting techniques and mapping of the movement of organic resources for soil fertility improvement. It was established that composting practices used by the community-based organisations (CBO’s), had an impact on the quality of the composts, which was found to be lower than the recommended international standards. The CBO’s involved regard composting activities as a business enterprise from where their livelihood comes. Low market opportunities (low demand) for their product have hampered their growth and development.. It was also observed that there is an inflow of organic nutrients in the form of animal manure imported into the city from the arid and semi arid livestock producing areas, some of which are as far as 300 km from Nairobi. In contrast, there is a big challenge in the disposal of the same product within the informal settlement areas of the city