The Brazilian savanna covers an area of about 180 million ha. The predominant soils are Oxisols commonly deep, well drained and well structured. They are highly acid, very low in nutrient status and susceptible to erosion. The rainfall distribution is an other problem for agricultural production in the region. Any soil management scheme to minimize these problems should aim to:
(a) improve the natural low soil nutrient status and neutralize part of the effects of soil acidity;
(b) minimize the risks related to dry spells and (c) protect the soil against erosion.