Agriculture Reference
In-Depth Information
to retain nutrients in the area. If the waste is collected by a centralized
organization, the inhabitants will need to store their wastes in separate
closable bins till the wastes are collected. The wastes can then be recycled,
composted or disposed of in a location specifi cally adapted to the purpose.
For instance, a centralized composting plant, using vermicomposting,
could treat organic wastes from an area and in turn supply the farmers of
that area with a high-quality compost, soil improver or organic fertilizer.
Depending on the local demand for energy, it is also possible to digest
the organic wastes with manure coming from livestock to produce biogas.
This can be done on household level or in a centralized way. The effl uent
of the biodigester can be used for fertigation and composting purposes, or
organic fertilizer can be produced.
On-site composting and vermicomposting can be implemented where
there is no, or very poor, waste collection facilities as the produced com-
post can be handled safely. These practices can also be done by families
with gardens so that they can reduce their fertilizer demands. Although
vermicomposting is more effi cient and can eventually produce valuable
side-products such as worms and proteins, it also requires more econom-
ical input (worms—i.e.,
Eisenia fetida
—need to be bought, a structure
needs to be constructed to contain the compost) to start-up, and thus by
studying both technologies local inhabitants can choose which compost-
ing type they prefer and can afford. The location of the (vermi-)compost-
ing can be in the vicinity of the house, to ease organic waste disposal, but
at a large enough distance to prevent the occurrence of noxious odors or
pests. The following is the presentation and discussion of vermicompost-
ing as an example of on-site organic waste management:
(1) Description of Current Situation
The separation and recycling of solid waste is an uncommon practice in
the peri-urban areas of Xochimilco. Although a number of inhabitants
have access to the centralized collection service, who collect the solid
waste with trucks, there are also households who do not make use of these
facilities, are not or irregularly visited by the trucks or simply do not make
use of the service. Hence solid waste is also burnt or discarded to the
streets and environment, resulting in pollution.
