THE MARACA RAIN-FOREST PROJECT .3. PASTURE DEVELOPMENT ON CLEARED FOREST LAND IN NORTHERN AMAZONIA

Pasture development on cleared forest land was investigated near Ilha de Maraca, N Roraima, Brazil. Initial forest clearance and burning in the area is followed by short-term crop cultivation, and conversion to pasture based on introduced grasses such as Panicum maximum and Brachiaria humidicola. Derived pasture is initially productive for cattle grazing, but its quality deteriorates as woody weed invasion increases. The quality of older pastures is variable, apparently as a function of grazing intensity and related management practices. Older pastures also appear to vary in respect of their total soil-plant nutrient content, but this is not directly reflected in soil nutrient levels. Local soils are inherently acid in character; they are not excessively degraded by pasture development, but are generally deficient in available P, which is presumably as limiting to pasture productivity. -from Authors