Summary
Amazon rainforest is fast being replaced by cattle pastures as investors respond to financial incentives and the lure of new highways. The Brazilian government's encouragement of pasture is linked to claims that pasture improves soil fertility and therefore represents a "rational" means of development in the Amazon. A review if information related to the ongoing debate concerning soil fertility changes under tropical American pastures casts doubt both on the claims of improved fertility for pasture growth, and on the presumption of indefinitely sustainable yields of beef cattle.