The function of tropical pastures

Pastures feed grazing animals and contribute to the stability of landscapes and of some cropping systems. Farmers who improve forage supply in the tropics seek to convert effectively the added forage grown to animal products, and to devise production systems which sustain forage yield in a resilient ecosystem.

The savannas of the tropics and subtropics (Tothill & Mott, 1985) constitute an immense natural resource. Much of these lands is inviolate, in the sense that it is only suited for grazing by ruminants, which can convert the long chain structural carbohydrates in the vegetation to products that are useful to humans (R. J. Jones, 1988b). These lands are not inviolate from overgrazing, and this book is concerned with the principles of managing pastures which take account of the requirements of both plants and animals for growth and replacement.

Livestock in the tropics and subtropics function in agricultural systems which are mainly extensive, with a low level of inputs, but which include some intensive dairy operations. In many regions there is a close integration of livestock with cropping; crop residues provide the main sources of feed, and animal draught power and nutrient return are crucial to the success of cropping. Meat, milk, fibre, and perhaps skins and hides, are the conventional livestock outputs for western societies; power, fuel, manure and capital accumulation may be equally significant in the functioning of farm systems in the tropics.