02396naa a2200277 a 450000100080000000500110000800800410001910000190006024500580007926000090013730000150014652015300016165000200169165000190171165000200173065000120175065000190176265000130178165000120179465000240180665000190183065000150184970000150186470000170187977302220189615523311997-02-05       1982    bl uuuu     u00u1 u    #d1 aGOEDERT, W. J.  aManagement of tropical soil and world food prospects.  c1982  ap.338-364.  aMeeting the future food needs of the world can be accomplished by increasing productivity in traditional areas and by occupation of new areas not yet cultivated. Tropical regions present both alternatives, but agricultural expansion seems more important, as 830 million hectares of potentially arable land are available. Shifting cultivation and cattle grazing are the most traditional activities and the present food production is scarcely sufficient for the native population. The tropical area is mostly covered by rainforests and savanna vegetation. The climate is hot and total rainfall is high; however, rainfall distribution constitutes a problem in some parts of the tropics. The predominant soils, Oxisols and Ultisols, are commonly deep, well drained and well structured, but they are highly acid and very low in nutrients, especially phosphorus. To solve or minimize these problems, any soil management scheme should aim at: (1) improving the natura low soil nutrient status and neutralize part of the soil acidity; (2) minimizing the risks related to dry spells; and (3) protecting the soil against erosion, since rainfall intensity is usually high during the cropping season. Once these goals are accomplished by soil management, over 800 million hectares can be put to use for intensive cultivation with annual and perennial crops and for cattle grazing. It is estimated that rational utilisation can result in more than enough food production to meet the needs of 2 billion people or more within 20 to 40 year.  afood production  asoil fertility  asoil management  asoil pH  aAcidez do Solo  aAlimento  aCerrado  aFertilidade do Solo  aManejo do Solo  aProdução1 aLOBATO, E.1 aRESENDSE, M.  tIn: INTERNATIONAL CONGRESS OF SOIL SCIENCE, 12., 1982, New Delhi. Whither soil research: managing soil resources to meet the challenges to mankind: transactions. New Delhi: Indian Agriculture Research Institute, 1982.