Victor B. Asio1, Reinhold Jahn2, Federico O. Perez3, Ian A. Navarrete4 and Sergio M. Abit Jr.1
The paper reviews the available information on soil degradation which is a major agricultural and environmental problem in the Philippines. Soil erosion appears to be the most widespread process of soil degradation and is also the most studied. Other important but less studied degradation processes include loss of nutrients and organic matter, salinization, acidification, pollution, compaction, and subsidence. Studies reviewed have shown that the widespread degraded upland soils possess chemical and physical constraints for crop growth like acidic or calcareous chemical condition, low organic matter and nutrient contents, shallow solum, presence of toxic substances and compaction. There is a need for more data on the physical and socio-economic characteristics of degraded lands to aid in the formulation
of appropriate soil management strategies to support biodiesel production in these unproductive lands which is now being promoted by the Philippine government.
Keywords: Degraded uplands, land use change, soil degradation, soil erosion, tropical soils