Completed Soil degradation and infertility are major constraints to the sustainability of agricultural systems in many developing countries, particularly those located in the tropical humid lowlands. Restoration of soil phosphorus (P) status can only be achieved by the use of phosphate fertilisers. Agronomists and agricultural economists, in both developing countries and development agencies, are not adequately aware of locally available phosphate rock resources and their agronomic potential as a low cost source of phosphate.

Technical Report J. D. Appleton, A. J. G. Notholt 2002 This report presents the second of a series of three regional reviews (covering sub-Saharan Africa, Asia, and Central and South America) that seek to provide advisers with a concise summary of national and regional information on locally available phosphate resources. The report deals with Central and South America with special emphasis on Bolivia, Brazil, Colombia, Peru and Venezuela.

Report JD Appleton 2002 Soil degradation and infertility are major constraints to the sustainability of agricultural systems in many developing countries, particularly those located in the tropical humid lowlands of Sub-Saharan Africa (SSA) where phosphorus (P) and nitrogen (N) deficiencies are recognised as major constraints to sustainable agricultural productivity.

Report JD Appleton 2002 Soil degradation and infertility are major constraints to the sustainability of agricultural systems in many developing countries, particularly those located in the tropical humid lowlands of Asia where phosphorus (P) deficiency is recognised as a major constraint to sustainable agricultural productivity. Whereas nitrogen deficits can be restored, at least in part, through the application of organic crop residues and manure or by the use of cover crops, the restoration of soil P-status can only be achieved by the use of phosphate fertilisers.