ABSTRACT Rheological parameters have been used to study the interaction between particles and the structural strength of soils subjected to mechanical stresses, in which soil composition and water content most strongly affect soil resistance to deformation. Our objective was to evaluate the effect of water tension on rheological parameters of soils with different mineralogical, physical, and chemical composition. Surface and subsurface horizons of four Oxisols, two Ultisols, one Alfisol, and one Vertisol were physically and chemically characterized; their rheological parameters […]

The objective of this study was to evaluate the physical, chemical, mineralogical and micromorphological characteristics of cohesive red, yellow and grayish soils in a toposequence of the Coastal Tablelands region in southern Bahia and northern Espirito Santo states. It was also sought to understand the mechanisms promoting their cohesion and fragipan formation. Therefore, the routine physical analyses, determination of the coarse clay/fine clay ratio, specific surface by BET-N2 and water vapor adsorption, magnetic susceptibility, scanning-electron microscopy analyses and the micromorphology […]

Through profile morphology and physical analysis (texture, bulk and particle densities, pore size distribution, water storage and retention, and field capacity determined “in situ”), the behavior of a yellow Latosol located in Cruz das Almas (BA), Brazil, was studied when subjected to irrigation. The results made showed that the AB and BA horizons were hard (cohesion), mainly when dry, becoming a strong mechanic impediment fot root growth , aeration and water movement; due to the presence of the hard layer, […]

The effects of continuous sugarcane cropping on the properties of a clayey Yellow Latosol were studied in the region of the Low Coastal Tablelands of Alagoas State, Brazil. Four sites were selected at Caeté mill, São Miguel dos Campos, AL, involving a native forest (Tn) and sugarcane fields cultivated for periods of two (T2), eighteen (T18) and twenty-five (T25) years. The soils were morphologically characterized and undisturbed samples of the A, AB, and BA horizons of each profile were collected […]