Environmental Engineering Reference
In-Depth Information
and shrubs that regenerate are expected to improve the soil fertility status of
the land through nutrient recycling. At the end of the fallow period farmers
return to the land and recultivate it with food crops. Food crops cultivated
under this system depend on the farmers' choice, and climatic and soil condi-
tions. Typical food crops grown are plantain, banana, cassava, yam, maize, and
vegetables.
The food crops/tree crops forest complex system of traditional agroforestry is
found in situations where food crops are cultivated under cash crops, which grow
under naturally dispersed forest trees. The system forms a three-tier storey with
the food crop at the lower level, the cash crop in the middle, and the forest trees
in the upper storey. The cocoa-plantain/banana-
odum
/
wawa
complex typifies
this system.
Rationale for leaving tree species
in situ
on farms
It has been observed that farmers practising the traditional cropping systems
leave quite a number of tree species on the farmland, either intentionally or for
convenience. Table 13.1 lists the most important tree species left
in situ
on
farms.
Farmers leave trees
in situ
on farms for various reasons. The main reason is
to conserve nature to derive future benefits and for immediate use, which
includes food, fodder, fuelwood, medicine, construction, and shade, and many
Table 13.1 Tree species left
in situ
in farms in the forest zone
Scientific name
Common name
Chlorophora excelsa
Odum
1
Terminalia superba
Ofram
1
Triplochiton scleroxylon
Wawa
1
Militia excelsa
Odum
1
(African teak)
Ceiba pentandra
Onyina
1
(silk cotton tree)
Terminalia ivorensis
Emire
1
(shingle tree)
Khaya ivorensis
Mahogany
Piptademistrum aficanum
Dahoma
1
Nuclea diderrichii
Kusea
1
Entandophragma angolense
Sapele
1
Microdermis puberia
NK
2
Albizia zygia
Okoro
1
Ficus anomani
Ficus
Cola gigantea
Owataka
1
(wild cola)
Lophira lanceolata
NK
2
Afzelia africana
NK
2
1. Local /vernacular names.
2. Not known.
