A comparison of two methods for the establishment of a silvopastoral system om degraded pasture land

摘要

In the mountainous area of southeast Brazil, two major constraints for the development of the degraded pasture land are: i) the main soils are very acid and infertile; ii) soil mechanization, for pasture sowing, is difficult and may enhance erosion, with loss of the surface soil, which is the most fertile. The low fertility of the main soils, particularly of the red-yellow latosol (oxisol), and the low carrying capacity of the naturalized molasses-grass (Melinis minutiflora) has led to its substitution for the more aggressive and higher yielding species of the genus Brachiaria. However, to be successful, the Brachiaria species establishment depend on the application of phosphorus fertilizers and on the use of a soil preparation method, not conduciveto soil erosion (Carvalho, 1998). In addition, the long term productivity of the sown grass pastures in these areas depend on the availability of a nitrogen source.