Environmental Engineering Reference
In-Depth Information
tion are mixed or monocrop depending on the farmers' circumstances and weather
conditions. Because of land shortage, continuous cropping is widely practised.
Traditional agroforestry systems
The traditional agroforestry systems in the coastal savanna zone assume the form
of trees scattered on rangelands and those on croplands. The first one, which
involves trees scattered on rangelands, is prevalent in the Accra plains. Trees on
the range serve as fodder and shade for livestock.
Griffonia simplicifolia
is noted
for its fodder, and medicinal seeds for the export market.
The second, which involves trees on cropland, also features as a traditional
agroforestry practice in the zone. Additionally, mangrove management is an age-
old practice along some of the coastline. In the Keta district in particular, the
inhabitants harvest the mangrove for fuelwood for fish smoking. There is mini-
mal planting of mangrove to replenish the stock.
Rationale for leaving trees
in situ
on farms
Farmers plant or maintain trees on their cropland primarily to obtain valuable tree
products such as fuelwood, charcoal, fodder, food, medicinal products, and fibre
(Table 13.5). Some also do so to restore fertility of the soil. The practice ensures
sustainability of the particular resource base, enhances biodiversity in the agri-
cultural environment, and makes the people self-reliant.
Management practices
Farmers generally carry out weeding on the croplands, which benefits the trees as
well. Tree pruning, coppicing, and pollarding are also undertaken to reduce
Table 13.5 Tree species left
in situ
in farms in the coastal savanna zone
Scientific name
Common name
Adansonia digitata
Baobab
Azadirachta indica
Neem
Anogeissus leiocarpus
Anogeissus
Blighia sapida
Akee apple
Borassus africana
Borasus palm
Ceiba pentandra
Silk cotton
Dalium guinenses
Dalium
Fumtumia elastica
-
Griffonia simplicifolia
-
Mangifera indica
Mango
Spondias mombin
-
