SOIL ORGANIC MATTER FRACTIONS IN PRESERVED AND DISTURBED WETLANDS OF THE CERRADO BIOME
01/Jan/2015
Veredas are humid tropical ecosystems, generally associated to hydromorphic soils and a shallow water table. The soils of these ecosystems are affected by the use of the areas around these veredas. The objective of this study was to determine soil organic matter (SOM) fractions in veredas adjacent to preserved (native savanna) and disturbed environments (agricultural areas and pastures) in the Cerrado biome. Soil samples were collected from the 0-10 and 10-20 cm layers along reference lines drawn along the relief […]
USE OF SCALED SEMIVARIOGRAMS IN THE PLANNING SAMPLE OF SOIL PHYSICAL PROPERTIES IN SOUTHERN AMAZONAS, BRAZIL
01/Jan/2015
There is a great lack of information from soil surveys in the southern part of the State of Amazonas, Brazil. The use of tools such as geostatistics may improve environmental planning, use and management. In this study, we aimed to use scaled semivariograms in sample design of soil physical properties of some environments in Amazonas. We selected five areas located in the south of the state of Amazonas, Brazil, with varied soil uses, such as forest, archaeological dark earth (ADE), […]
COMPARISON OF SAMPLING PROCEDURES FOR TRAINING PREDICTIVE MODELS IN DIGITAL SOIL CLASS MAPPING
01/Jan/2015
The predictive models used in digital soil mapping (DSM) need to be trained with data that most fully capture the variation of terrain and soil properties in order to generate adequate correlations between environmental variables and the occurrence of soil unities. Several methods have been used in DSM to evaluate the accuracy of these models. The aims of this study were to compare the use of three sampling procedures for training a classification and regression tree (CART) algorithm, and evaluate […]
USE OF SCALED SEMIVARIOGRAMS IN THE PLANNING SAMPLE OF SOIL CHEMICAL PROPERTIES IN SOUTHERN AMAZONAS, BRAZIL
01/Jan/2015
The lack of information concerning the variability of soil properties has been a major concern of researchers in the Amazon region. Thus, the aim of this study was to evaluate the spatial variability of soil chemical properties and determine minimal sampling density to characterize the variability of these properties in five environments located in the south of the State of Amazonas, Brazil. The five environments were archaeological dark earth (ADE), forest, pasture land, agroforestry operation, and sugarcane crop. Regular 70 […]
Pedogenesis and classification of latosols developed from itabirites in the region of Quadrilátero Ferrífero in Minas Gerais
01/Apr/2014
Located in the Midwest of the State of Minas Gerais, a region called Quadrilátero Ferrífero covers an area of approximately 7,000 km2. Since the seventeenth century, it is known as gold- and iron-producing province, and the geological context is therefore one of the best-studied of Brazil. The regional topography is very rugged, with mostly poorly developed pedogenesis, especially Cambissolos Háplicos, Neossolos Litólicos and Neossolos Regolíticos. In a smaller proportion and on colluvial ramps (hilly relief), very Fe-rich Latossolos Vermelhos occur, […]
Using numerical classification of profiles based on Vis-NIR spectra to distinguish soils from the Piracicaba Region, Brazil
01/Apr/2014
Considering that information from soil reflectance spectra is underutilized in soil classification, this paper aimed to evaluate the relationship of soil physical, chemical properties and their spectra, to identify spectral patterns for soil classes, evaluate the use of numerical classification of profiles combined with spectral data for soil classification. We studied 20 soil profiles from the municipality of Piracicaba, State of São Paulo, Brazil, which were morphologically described and classified up to the 3rd category level of the Brazilian Soil […]
Mineral assemblage of soils developed from different lithologies in southern Minas Gerais, Brazil
01/Feb/2014
Systematic studies on of soil formation factors are relatively scarce in Brazil since comprehensive samplings of a variable factor while keeping others constant are difficult to perform. Near Lavras, Minas Gerais, there is wide geological diversity over a small area, which offers a chance to assess the control exerted by different lithologies on mineral suites and other soil properties. Thus, eight soils overlying quartzite, mica-schist, gabbro, itabirite, serpentinite, meta-limestone, gneiss and phyllite, under similar climate and tropical, semideciduous forest conditions […]
Experimental use of ground-penetrating radar (GPR) to investigate tablelands in the northern coast of Bahia, Brazil
01/Jun/2002
Nine profiles were studied along a toposequence developed on Barreiras Group sediments, in Fazenda Rio Negro, Entre Rios, Bahia, Brazil. Besides conventional analysis, an electromagnetic probe through GPR – Ground-Penetrating Radar was employed. The objective of this study was to analyze the use of this tool in the acquisition of information on features occurring underground, by comparing the radargrams and pedologic descriptions obtained in the area. The equipment used was a Geophysical Survey model, with an 80 MHz antenna. The […]