ABSTRACT Soils classified as Alisols are very frequent in the sedimentary agricultural areas of southern Brazil. The presence of red mottles with morphology similar to plinthite and saprolite residue is very common in these soils, and its identification can be considered a difficult task, both in the field and in the laboratory. The incorrect identification of these redoximorphic features can affect soils’ taxonomic and technical classification. We aimed to compare morphological, physical, chemical and mineralogical data to identify reddish mottles, […]

Despite numerous studies conducted on the lower limit of soil and its contact with saprolite layers, a great deal of work is left to standardize identification and annotation of these variables in the field. In shallow soils, the appropriately noting these limits or contacts is essential for determining their behavior and potential use. The aims of this study were to identify and define the field contact and/or transition zone between soil and saprolite in profiles of an Alisol derived from […]

Dark subsurface horizons with morphological characteristics similar to sombric horizons are found in higher altitude areas of the eastern portion of the Sul-Rio-Grandense Shield, Brazil. They developed in the A2, AB (or AC), and BA horizons of Ultisols, Alfisols, and Entisols. The mechanisms responsible for their genesis are still poorly understood, although most authors agree on the illuvial origin of the humus horizon and on its diagnostic character. The objective of this study was to characterize and analyze nine soil […]

Despite evidences that soil morphology and classification can be used to infer measurable soil properties and to correlate management results among different agricultural sites, there is still the need of data to support many of those inferences. The aim of this research was to validate the use of soil morphology and taxonomy to predict soil properties based on measurements and analyzed by geostatistics, mainly those related to Nitic and Ferralic/Oxic soil horizons. Three selected soil profiles under no-tillage and fallow […]

The soil types Neossolos Litólicos (Leptosols) and Neossolos Regolíticos (Regosols) have been poorly studied in Brazil, due to their relatively low potential for agricultural use. Consequently the morphological description of Neossolos in the field is also hampered, particularly in terms of contacts between soil, saprolite and rock, and their classification in the Brazilian Soil Classification System. The purpose of this study was: to define morphologically the contact between soil, saprolite and rock in Neossolos; generate data of the saprolite layer […]

Soil or land leveling, a process of adequation of land surface, is being practiced in many rice-growing farms in the state of Rio Grande do Sul, Brazil. This process produces profound changes in the morphological, physical, chemical, and biological properties of the soil. To study these changes, test areas were selected with homogeneous surfaces where Planosols occur and on which land leveling was performed for eight years, one year, and one month and with original soil, at São João do […]

Tensiometers were installed in a 25 m2 area plot, every 15 cm, at depths varying from 30 to 240 cm, with three repetitions, to determine the matric potential (φm) of a “Terra Roxa Estruturada Latossólica” soil. Its volumetric water content was also indirectly measured by using the soil water retention curve. The θ-method (Libardi et al., 1980) fitted the soil redistribution profiles (θ vs t) with determination coefficients (R2) greater than 0.98. The hyphotesis of a unit hydraulic gradient was […]