Some Aquic Tropudalfs in the Vicinity of Villa Banzer and San Carlitos in Northeastern Bolivia

Abstract

Several soil profiles were examined near settlements around San Carlitos and Villa Banzer, some 30 and 100 km, respectively, from Trinidad, capital of the Department of Beni, in northeastern Bolivia. In general, the soils appear to be Aquic Tropudalfs. They are very deep; internal drainage varies from moderate to slow; external drainage is slow. Textures are moderately fine to fine with very high (from 42 to 65%) silt content. Clay increases in the 82 horizon as compared to the A₁. The combined silt and clay content in this horizon ranges from 85 to 96%. Organic matter levels of the surface soils are at least as high as those of other tropical- and temperate-region soils. The soils are strongly acid in the upper layers. CEC seems to be related to organic matter activity in the surface layers and then more to clay content at lower depths. The soils of the areas studied appear suitable for crops such as rice, corn, and cassava. Major problems affecting soil utilization are those related to drainage and irrigation. Liming and fertilization are key factors in developing adequate agricultural programs in the region .