Environmental Engineering Reference
In-Depth Information
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states the rationale for and attributes of the above-mentioned practices
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highlights the relevant management practices.
In Ghana the five main agro-ecological zones are:
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forest
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forest-savanna transition
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Guinea savanna (southern sector of the interior savanna)
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Sudan savanna (northern sector of interior savanna)
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coastal savanna (Map B).
Forest zone
The forest zone covers the Western, greater parts of Ashanti, parts of Brong
Ahafo, Eastern, and Volta regions and some parts of the Central region. These are
administrative regions. As such, they are capitalized. It makes up roughly 33 per
cent of the country's land mass, and comprises subclasses such as the wet ever-
green, moist semi-deciduous, and dry semi-deciduous forests. It enjoys a bimodal
rainfall pattern with a mean annual range of between 1,500 and 2,000 mm. Soils
are dominated by forest ochrosols and oxysols.
Traditional cropping systems
Traditional cropping systems practised in the forest zone include mixed cropping,
monocropping, and intercropping.
The mixed cropping system involves the growing of different crops on the same
piece of land at the same time. Crop combinations found in the system include
maize/cassava/vegetable and plantain/cocoyam/yam. These crop combinations can
be found among the major cash crops such as cocoa, coffee, oil-palm, and citrus
in the early stages of their cultivation. The mixed cropping system promotes crop
diversity, enhances food security, and makes efficient use of land and labour.
In the case of monocropping, also known as sole cropping, a single crop is
grown on a piece of land over one or two cropping seasons. Maize, rice, cas-
sava, and tomato are usually grown in this system. The practice is however not
widespread because of the economic and ecological risks associated with it.
Traditional agroforestry systems
In the forest zone, two main traditional agroforestry practices can be recognized,
namely bush fallowing, and tree crop/cash crops/forest complex.
The bush fallow system basically involves the growing of food crops for a
period extending between one and three years on newly cleared land, and leaving
the land to fallow for between four and 10 years. During the fallow period, trees
