Environmental Engineering Reference
In-Depth Information
the gestation period lasts for 140 to 160 days. A litter of five to nine is normally
produced. The babies are breastfed for about two weeks, after which they are
ready to go on grass feed. The young grasscutters are weaned after six to eight
weeks, after which the mother is rested for two to three weeks and crossed again
when on heat. The interval between litters is roughly seven months. The females
remain reproductively active for a minimum of five years.
Little information is available on the diseases encountered on peasant farms.
However, with proper sanitation and isolation practices, disease attack is not
a major problem.
Marketing
The animals are ready for slaughter from 2 kg body weight and above. The
females attain about 2.5 kg and the male around 4 kg at 18 months. The grasscut-
ter meat is marketed whole. Opportunities exist for marketing live animals when
inexpensive methods of restraining them during transportation are developed.
Cultivation of yams in conserved forests
Yam is an important staple food crop in Ghana and elsewhere in West Africa. Its
diversity and ways of managing it for food security are discussed with special
reference to southern and northern Ghana in Chapters 7 and 8.
Yam species such as the bush yams (
D. prahensilis
), the bitter yam
(
D. dumeturum
), and the aerial yams (
D. bulbifera
) may be integrated into for-
est agriculture by growing them along with forest trees or compatible tree
crops like cocoa, as a reliable year-round source of food and for supplemen-
tary income generation. The adaptation of the bush yams to forest conditions
offers an opportunity to incorporate them into a fallowed forest alongside other
income-generating activities such as snail raising and beekeeping. This will
ensure that farmers continue to derive some income from their lands during the
fallow period and, thus, give them an incentive to lengthen the dwindling
fallow periods.
The yields from the bush yams and water yams are very high and they consti-
tute a significant source of income to the farmers. However, several varieties have
very short storage life and losses are high. If the processing aspect is tackled to
ensure a good market outlet, yam is a crop whose production can be increased by
the farmers with little or no disruption to the environment.
In some parts of Ghana yams are grown in monoculture on clean cultivated
fields and staked with bamboos, branches of trees, or stems of young trees that
are harvested from the wild. This system is inimical to both soil and biodiversity
conservation. The use of specially conserved trees, notably
Newbouldia
sp., for
