ABSTRACT
The uplands of the Philippines, which are dominated by rugged, hilly topography, have experienced widespread conversion of forest to permanent agriculture based on rice, maize, root crop cultivation, and animal production. Traditionally, upland farmers have relied on fallowing to maintain soil fertility, a practice that is successful as long as the length of the fallow period is sufficient to allow for regeneration of the natural vegetation. However, an increasing human population in the uplands coupled with finite land resources has resulted in a dramatic reduction in the length of the fallow period and its capacity to restore soil fertility. The consequence of continuous cropping, lack of soil conservation measures, and heavy grazing by ruminants has been severe soil erosion and fertility depletion.
