Agriculture Reference
In-Depth Information
and commercial poultry farms, which produce large quantities of organic
wastes. The daily domestic waste generation in Kumasi is about 610 tonnes.
The two main markets generate an additional 250 tonnes per day, most of
which is organic; thus, the total city-wide generation is about 860 tonnes per
day (KMA-WMD, 2000). Farming and trading are the main income-
generating activities in Kumasi. Commercial crop production is dominated
by vegetable horticulture and staple crops such as plantain, maize and
cassava. In partially waterlogged valley bottoms, sugarcane and taro are also
grown.
Kumasi is an ideal city to promote composting as a waste management
strategy due to the large amount of organic wastes that are generated, the
high biodegradable organic fraction of solid waste ranging between 65 and 75
per cent and the extensive agriculture within its peri-urban boundaries
(Salifu, 2001). A pilot composting plant was established in the Buobai suburb
of Kumasi in 2001 by the IWMI and Kumasi Metropolitan Assembly (KMA).
Different composts were produced from market wastes, household solid
wastes and dewatered human sewage from septic and public toilets. During
the inception of this composting project, the stakeholders wished to know the
farmers' perceptions and demand for compost in Kumasi. At the onset of
compost production, its agronomic potential and benefits to urban and peri-
urban farmers had to be evaluated. This paper presents results of two
composting studies.
O
BJECTIVES
The objectives of this project were to conduct a social, economic and
agronomic evaluation of compost made from urban organic solid wastes and
fecal sludge, as well as an evaluation of its potential benefits in urban
agricultural systems of Kumasi.
The social and economic evaluations were conducted through individual
interviews and focus group discussions with relevant stakeholders. The
objectives of these interviews were to: examine and document the farmers'
perceptions, knowledge and socio-cultural acceptability of the compost;
estimate the farmers' WTP for the compost compared with other common
soil inputs; determine the socio-economic factors affecting farmers' WTP; and
determine the demand for compost by farmers. Agronomic benefits of the
compost were evaluated in seed germination and phytopathology experiments
in the screenhouse and field trials. The objectives of these experiments were
to: determine the success of germination and growth of vegetables to
increasing rates of compost; determine whether the compost suppresses root
knot nematodes, Fusarium wilt and Sclerotium rolfsii in lettuce and tomato
plants; compare the fertilizer value of the compost with that of poultry
manure; and determine the residual nutrient effects of compost applications
on lettuce yield and soil fertility.
