Replacement of Natural Covers

Abstract

It has been said that it is only under particularly favourable conditions of climate, soil and economics that one may consider replacing the natural plant cover of tropical grazing lands entirely, by clearance, ploughing and seeding or planting of adapted species of grasses and legumes (Bommer, 1966; Moore, 1970; Wilson, 1968). It may be possible in State-owned land or farms, or where ranching companies are operating (Moffat, 1966). In limited areas, ecoclimatic and economic conditions are favourable, e.g. Queensland, Jamaica (Richards, 1970) and perhaps other places in the Caribbean and Central America, parts of Brazil (Rocha, 1972), the highlands of Kenya (Bogdan, 1959; Morrison, 1966, 1969), other parts of east Africa (Stobbs, 1969d), Ghana (Kannegieter, 1966), and Hawaii (Plucknett, 1970). Elsewhere, one cannot expect the ordinary grazier to be willing and able to provide the energy and capital that would be necessary, no matter what the urban-based departments and their well-meaning research agronomists and field advisers may recommend as desirable for the national good. It is difficult to see any long-term or permanent role for sown pastures in India (Whyte, 1971), in Sri Lanka (Andrew) & Jayawardana, 1970), or in Taiwan (Davies, 1970), in spite of the work of the UNDP/FAO project on marginal lands at Tainan, or in central Laos (Thomas & Humphreys, 1970).