The Ugandan population is currently growing at
3.3 percent (Uganda Bureau of Statistics, 2016). There is thus a need to
produce more food for the growing population with minimal damage to the
environment (World Bank, 2018). However, soil fertility and climatic patterns
are deteriorating (Semalulu & Kayuki, 2015). There is a possibility to
improve soil fertility sustainably through the application of compost (Asare
& David, 2011). This is cheaper because municipalities and cities are
grappling with excess waste which can be turned into compost manure.
Municipal waste is becoming a menace
to many urban establishments (NEMA, 2016). The processing of urban waste can be
an affordable source of soil nutrients and yet relieve urban authorities of
this ‘waste burden.’ Urban waste may be processed and used on agricultural land
where they have a significant fertilizer value (Abulsoud & Hadid, 2015).
The municipalities of Uganda generate a lot of waste but garbage collection and
transportation to dumping sites is poorly managed and ineffective. Some
dumpsites are inappropriately located, and these merely cause further adverse
effects to the surrounding environment and ultimately to human health (NEMA,
2016). The poorly managed organic waste may, for example, generate greenhouse
gases that may contribute to climate change.
The World Bank provided US$ 350,000
to Uganda for the development of modern technology to treat urban waste and
turn it into compost manure (World Bank Group, 2019). This technology was only
implemented in a few municipalities owing to its complexity. The National Environment
Management Authority (NEMA) is also building the capacity of nine municipal
councils to manage solid waste as a way of reducing greenhouse gas emissions
into the atmosphere and provide farmers with a cheaper and eco-friendlier
compost fertilizer (NEMA, 2017). In many cases, the degradation of the waste
materials is achieved by beneficial micro-organisms that require huge
technological investment. There is a need to devise a cheaper technique e.g.
use of earthworms for biodegradation.
Culturing red earthworms (Eisenia fetida) is one cheaper option to
have enough worms for municipal waste biodegradation and this has been studied
in some parts of the world (Domínguez, Aira, & Gómez-Brandón, 2010; Singh,
2014). E. fetida (alias compost worm, manure worm or red wiggler) is the
commonest worm type used for vermicomposting. Vermicomposting means using
earthworms to convert organic manure into vermicompost, humus – like material.
This is preceded by vermiculture that refers to raising (multiplying) earthworms
to increase their number. Vermiculture and research on red worms are already
happening mainly at the following universities in Uganda; Ndeje, Makerere and
African Rural University (ARU, 2019).
The red worms start producing at two
months and live up to one or two years. There are over 7,000 worm species
however, E. fetida is the most
suitable for compositing. The earthworms decompose organic manure, cycle, and
recycle nutrients to increase crop yield, improve soil structure, eject casts
which are growth media for micro-organisms and are also medicinal. There are
six things to care about when rearing earthworms i.e.; bedding material, food
source, moisture content, adequate aeration, protection from temperature
extremes, and protection from predators.
The vermiculture and vermicomposting
technology has lots of potentials to address the urban waste menace and soil
fertility challenges in Uganda and generally in Africa. It is a relatively
cheaper and environmentally friendly technology of mitigating pollution and
other waste related challenges. A lot needs to be done to develop the capacity
for this technology to increase its success rate globally.
This post is also available in: French