SUMMARYThe agricultural potential of Latosols of the Brazilian Cerrado region is high, but when intensively cultivated under inappropriate management systems, the porosity can be seriously reduced, leading to rapid soil degradation. Consequently, accelerated erosion and sedimentation of springs and creeks have been observed. Therefore, the objective of this study was to evaluate structural changes of Latosols in Rio Verde, Goiás, based on the Least Limiting Water Range (LLWR), and relationships between LLWR and other physical properties. Soil samples were collected from the B horizons of five oxidic Latosols representing the textural variability of the Latosols of the Cerrado biome. LLWR and other soil physical properties were determined at various soil compaction degrees induced by uniaxial compression. Soil compaction caused effects varying from enhanced plant growth due to higher water retention, to severe restriction of edaphic functions. Also, inverse relationships were observed between clay content and bulk density values (Bd) under different structural conditions. Bd values corresponding to critical soil macroporosity (Bdc MAC ) were more restrictive to a sustainable use of the studied Latosols than the critical Bd corresponding to LLWR (Bdc LLWR ). The high tolerable compression potential of these oxidic Latosols was related to the high aeration porosity associated to the granular structure.Index Terms: soil compaction, degradation of agricultural soils, soil penetration resistance, water availability, soil texture.
RESUMO: ALTERAÇÕES ESTRUTURAIS DE LATOSSOLOS REPRE-SENTATIVOS DA REGIÃO DO CERRADO: I -RELAÇÕES EN-TRE PROPRIEDADES FÍSICAS DO SOLO E INTERVALO HÍDRICO ÓTIMO