Modeling of Latosol development on geomorphic surfaces of the Brazilian Central Plateau: First results.

Latosols are deeply weathered soils characteristic of the moist tropics. Many Latosols have kaolinitic horizons overlying more gibbsitic ones (Lucas, 1989), for which there has been no satisfactory pedological explanation and why they have often been considered as a sedimentary succession. Several hypotheses to explain this phenomenon were expressed: biogeochemical recycling of Si by the forest (Lucas et al., 1993) or the activity of termites (Volland-Tuduri, 2005). The objective of this study is to model the development of Latosols of the Brazilian Central Plateau considering the respective effect of parent material, time or biological activity. This plateau is constituted of the two main geomorphic surfaces: the South American surface (Suface I) and the Velhas surface (Surface II). In the Central Plateau, the Latosols can be identified as Red Latosols (~28%), Yellow Red Latosols (~10%) and Yellow Latosols (~2%), (Reatto, 1998)