ABSTRACT Soils with andic properties are characterized by a low apparent density, variable charges, large amounts of allophanes, imogolite, ferrihydrite, and/or organo-metallic complexes with Al, and present high phosphate retention. Soils derived from non-pyroclastic materials rich in silicates, formed under a cold and humid climate, a large amount of organic carbon, acid weathering, andic properties can manifest when a large amount of Al is present in the form of organo-metallic complexes. This study aimed to evaluate the characteristics and geographical […]

ABSTRACT There is a growing demand for more detailed knowledge about soils, their functions, and connections with human activities and environmental services. In Brazil, where soil survey and mapping have been scarce since the 1990s, there is a remarkable sense of urgency. Recently, a national soil program was created (PronaSolos) to attend to the massive demand for soil information. PronaSolos is an effort to return to the systematic soil mapping of the national territory, which requires many pedologists who master […]

ABSTRACT The classification of Spodosols on the second categorical level (suborder), according to the Brazilian Soil Classification System (SiBCS), is done by observing the colors of genetic horizons in the field. The presence or absence of iron oxides is the main factor for this classification, and the color of the horizon is the criterion currently adopted. However, the simple observation of color in the field can be mistaken and cause an error in the definition of the second categorical level. […]

ABSTRACT Soils in alluvial plains of the lower course of the Acaraú River, Ceará State, Brazil, are weakly developed and have a complex distribution in the landscape. This study reports the pedogenic characterization of such soils in an effort to understand their formation. Soil pits were opened in four representative sites, profile morphology was described, and soil samples were collected for chemical, physical, mineralogical, and micromorphological analyses. All profiles had weak pedogenic development, as inferred from their morphological characteristics, lack […]

ABSTRACT The assessment of spatial variability of environmental variables such as soil properties is important for site-specific management. A geostatistical index that allows quantifying and characterizing the structure of spatial variability is fundamental in this context. Thus, this study aimed to develop a new spatial dependency index, called the Spatial Dependence Measure (SDM) for the spherical, exponential, Gaussian, cubic, pentaspherical, and wave semivariogram models; and comparing it with some of the indexes available in the literature. The SDM is also […]

ABSTRACT The term Post-Barreiras is a definition for sediments above the deposits of the Barreiras Formation, and the genesis of soils in these environments must be related to sedimentary deposition. Our objective was to apply multi-technique analyses to characterize the sediments and soils to understand pedogenesis in these environments. We analysed sedimentological parameters and the geochronology of sediments. Morphological, chemical, and mineralogical analyses allowed the characterization of the soil. Also, these data supported the analysis of lithological discontinuity. We considered […]

ABSTRACT The northwestern part of the Acre State (Brazil) possesses singular soils in Brazilian Amazonia, but have been very little studied. This study aimed to discuss the genesis and some micropedological aspects of the soils from Serra do Divisor and adjacent floodplain soils of the Moa river, to enhance the knowledge on their formation. A toposequence of soils ranging from the uppermost part of sub-Andean Serra do Divisor to the Alluvial soils of Moa river floodplain was studied, regarding chemical, […]

ABSTRACT Notwithstanding the importance of soil surveys, advances in digital soil mapping have mainly focused on mapping soil attributes or properties rather than developing digital maps of soil units or soil classes. The purpose of this research was to develop digital soil unit maps based on primary soil data collection in areas without previously collected soil information. The covariate variability, the random effect across the data subset and the map outputs were the focuses of this study. We used five […]

ABSTRACT The pedological studies carried out so far in Trindade Island (TI) have obtained patchy evidences of allophane, without detailed mineralogical and micromorphological studies to confirm the occurrence of Andosols in TI. Therefore, in this study, the mineralogical, micromorphological, physical and chemical characterization of four soil profiles from Vulcão do Paredão (P1) and Morro Vermelho formations (P2, P3, and P4) were carried on the latest volcanic events in Brazil from Trindade Island (TI) with the aim of to evaluate the […]

ABSTRACT Soil maps are important to evaluate soil functions and support decision-making process, particularly for soil properties such as pH, carbon content (C), and cation exchange capacity (CEC), but the spatial resolution and soil depth should meet the needs of users. On another hand, the efficiency of statistical models to create soil maps, with an acceptable level of accuracy, often require a large number of samples with an appropriate distribution across the area of interest. However, accessibility for sampling can […]