Representative soil profiles from the Agroindustrial District of Jaíba in northern Minas Gerais State, Brazil, were morphologically described, sampled and chemically, physically and mineralogically analyzed, to obtain data which could contribute to their improved utilization. Although the parent material was almost the same (Bambuí group limestone), and the apparent physiographical homogeneity (flat relief and deciduous forest), the soils presented great morphological, chemical and mineralogical diversity. From a mineralogical standpoint, illite and kaolinite are common minerals, the latter found even in Vertisols and Rendzinas, which are soils with substantial amounts of free carbonates. The presence of smectite in Vertisols, Rendzinas and Cambisols of high activity clay, indicates that rain shortage, richness of parent material and its shallow depth on a flat topography, hinder the escape of silica and bases from the system, favoring the smectite formation. The mineralogical composition, together with the climatic seasonal variability, appears to be responsible for the accentuated cracking of these soils in the dry season. The soils present various colors: red, and red-yellow, due to the presence of hematite and goethite, mainly in Oxisols on slightly elevated landscape positions, therefore with better drainage; yellow and yellowish-brown colors, normally in the more depressed areas, with worse drainage, associated with the shallow depth and high density of the parent material, favoring the genesis of goethite and leading to significant amounts of manganese-iron concretions, with occurrence of Cambisols with high (Ta) and low activity (Tb) clays, Vertisols or soils with vertic characteristics, also brownish, and Rendzinas. The low Fe o/Fe d ratio (iron oxalate/iron dithionite) revealed predominance of more crystalline iron oxides. The eutrophic and epieutrophic soils (dystrophic or allic) with low Na contents and a dominantly flat and gentle undulated relief confirm the great agricultural potential of the area, especially under irrigation. However, the soil chemical, physical and mineralogical characteristics diversity indicates variable soil beahavior depending on land use, suggesting the adoption of differential soil management practices.
Soils derived from limestone; Vertisols; Mollisols; Latosols