Fragipans and Duripans are frequently found in soils developed from sediments of the Barreiras Formation, in the low coastal plateaus of northeastern Brazil. Previous studies in arid regions have attributed Duripan cohesion to the amorphous silica. However, the Duripans and Fragipans in northeastern Brazil are located in semi-arid and high annual precipitation level zones (1.500 to 2.000 mm year-1). This study, based on a detailed characterization of soils from four depressions with different sizes, aimed to propose an evolution scheme […]

This work aimed to measure and analyze total rainfall (P), rainfall intensity and five-day antecedent rainfall effects on runoff (R); to compare measured and simulated R values using the Soil Conservation Service Curve Number method (CN) for each rainfall event; and to establish average R/P ratios for observed R values. A one-year (07/01/96 to 06/30/97) rainfall-runoff data study was carried out in the Capetinga watershed (962.4 ha), located at the Federal District of Brazil, 47° 52′ longitude West and 15° […]

Aiming to evaluate the influence of the clay fraction mineralogy on the physical properties of Latosols (Oxisols) from southeastern Brazil, seven Latosols, representative of this group, were selected from the states of Minas Gerais and Espírito Santo, having distinct morphological features associated with soil structure. The sampling of soils was performed in the latossolic B horizon, with disturbed and undisturbed samples being collected. Chemical, physical and mineralogical characterizations were performed in the laboratory. Regression and correlation analyses taking into account […]