Environmental Engineering Reference
In-Depth Information
the other hand, are usually developed following total land clearing. They could
be developed from grass-, shrub-, and/or tree-dominated fallows.
The orchards are usually interplanted with cocoyams and plantains depend-
ing on the stage of their development. In the case of citrus and oil-palm, other
annual food crops, notably maize and cassava, are also interplanted until the
closure of the canopies of cocoa and oil-palm. Thereafter, interplanting is
possible only in citrus plantations.
Annual cropping
Distinct field types under this land-use category include mono- or intercrops of maize
and cassava, and monocrops of vegetables (tomatoes, okra, garden eggs, peppers, and
cabbages). The most common in this land-use category, however, is the maize/cassava
intercrop. Monocrops of vegetables were found to be popular among younger
farmers who practised market gardening in order to take advantage of the nearby
urban market in the city of Kumasi. The cultivation of these vegetables, usually in
valley bottom lands, is always associated with the indiscriminate use of pesticides,
with or without the use of chemical fertilizers and/or supplementary irrigation.
Grass-, shrub-, and tree-dominated fallows
Fallows dominated by grass, shrubs, and trees are common in Tano-Odumasi.
Grass-dominated fallows are usually fallow fields emerging from a period of
continuous annual cropping.
With a sustained period of fallow (four to five years), shrubs develop and
gradually shade out grasses to result in the shrub-dominated fallow.
Tree-dominated fallows usually result from abandoned small peasant agro-
forests,
afupa
, which begin the fallow cycle with shrubs.
The difference between the two shrub-dominated fallows lies in the higher
preponderance of trees and other plant species in the fallow with the recent
history of agroforestry.
The concept of good and bad trees
Although a new Forestry Law now recognizes the rights of the landowner to trees
occurring on his/her land, certain farmer perceptions with regard to trees in the
various land-use stages can affect farmers' attitudes towards nurturing trees on
their land. Farmers in Tano-Odumasi believe that their crop plants perform
differently in proximity with different trees, hence the concept of good and bad
