Numéro #43

Tropical grasslands : possibilities for a more intensive management

This paper presents a discussion of the problems and possibilities of a higher grassland production in the tropics. It is essentially based on both the results of the author in the West Indies end discussion of others in Australia, Africa, West-Indies and tropical America. Four principal parts are dealing with : yields with grasses or legumes in the tropics, different levels of management in terms of intensive use, problems of seasonal differences in the growth rates, problems of nutritive value and criteria of quality for tropical fodders. It is emphasized that grasses are able to give yields (from 7 to 50 thousand pounds of dry meter per acre per year) which are twice as high as those given by legumes.The use of legumes should be of better interest in countries where the environmental conditions does not give a maximum potential for the grass growth. In the best humid conditions, with high amounts of fertilizers, it seems easier to grow grasses and legumes on separate fields, mainly if little land is available for grassland. Several interesting datas are given about the rate of growth of different Digitaria species, as also about the rate of growth of Pengola grass in different soils and climatic conditions. Problems of fertilization and management are discussed with general reference to grass composition and its variations.