Bulk density (ρb) is an important indicator of soil physical quality, but it is seldom assessed at greater depths due to sampling difficulties. Pedotransfer functions have been relatively successful in estimating ρb, but specific functions for most Brazilian biomes are not available. The aim of this study was to develop mathematical functions to describe ρb to a depth of 1 m in areas of native vegetation in central and southern Minas Gerais, Brazil. For determination of ρb, soil core samples […]

Correlation between physical and chemical characteristics of soils and their natural mercury content is important for identifying the parameters that most influence Hg retention in these soils and its distribution in different environmental compartments. The aim of this study was to quantify the Hg content of tropical soils without anthropogenic influence and correlate it with physical and chemical soil characteristics. The present study is relevant because most research focuses on contaminated soils and, in the case of tropical soils, research […]

The area under the no-tillage system (NT) has been increasing over the last few years. Some authors indicate that stabilization of soil physical properties is reached after some years under NT while other authors debate this. The objective of this study was to determine the effect of the last crop in the rotation sequence (1st year: maize, 2nd year: soybean, 3rd year: wheat/soybean) on soil pore configuration and hydraulic properties in two different soils (site 1: loam, site 2: sandy […]

Macroporosity is often used in the determination of soil compaction. Reduced macroporosity can lead to poor drainage, low root aeration and soil degradation. The aim of this study was to develop and test different models to estimate macro and microporosity efficiently, using multiple regression. Ten soils were selected within a large range of textures: sand (Sa) 0.07-0.84; silt 0.03-0.24; clay 0.13-0.78 kg kg-1 and subjected to three compaction levels (three bulk densities, BD). Two models with similar accuracy were selected, […]

The dispersion of Oxisol samples can be somewhat difficult due to highly stable microaggregates that are not always completely destroyed by chemical and mechanical dispersion. It is therefore important that chemical and mechanical methods are combined, along with the pretreatment of the sample, for complete and stable soil particle dispersion throughout the analytical procedures. Thus, this study aimed to evaluate the efficiency of mechanical dispersion (slow agitation with an orbital shaker – 30 rpm for 16 h, in the presence […]

The time-domain reflectometry (TDR) technique has been one of the most used techniques to determine soil volumetric water content (q) owing to some favorable characteristics such as high precision, non-ionizing radiation and little influence of soil salinity, bulk density and texture. However, most of the TDR equipment and probes available do not allow a detailed measurement along the soil profile, as for instance the neutron probe does. For conventional TDR probes holes or trenches must be opened in the soil […]

Cattle ranching is one of the main economic activities in the agrosystem of Itapetinga, state of Bahia, Brazil. This activity is known to cause direct impacts on soil, subsoil and vegetation. This study aimed at verifying changes in soil chemical characteristics and texture under different vegetation covers in the cattle ranching region of Itapetinga by sampling soils in a primary forest-secondary forest-pasture sequence. Soil samples were collected along a transect with 36 small trenches, 60 cm deep, spaced 5 m apart (12 […]

Gully erosion are very common in areas with gneiss basement rocks. Their development is strongly influenced by subsuperficial processes, although the surface ones are also important. This study aimed to investigate the subsuperficial erosion mechanisms of these gullies and to understand how mineralogy and texture could influence the saprolite erodibility. Some basic trials and erodibility tests were carried out in representative samples, with imphasis to especially the pin-hole test. The results showed that seepage erosion does not occur and that […]

Knowledge on soil shear strength can actually be a very useful tool for the control of slope and gully erosion, as well as for the introduction of mechanical conservation practices in agricultural soils. In order to evaluate the shear strength of five soils in the region of Lavras (MG) and its relation with the weathering rate, an experiment was carried out, using a direct shear machine which allows the collection of undisturbed soil samples. These samples were collected at a […]

An empirical equation to represent the analytical soil particle-size curve is proposed. Based on this equation, a new expression was obtained to calculate the predominant mean diameter of soil particles, which represents the mean size of these particles. The equations can be applied, advantageously, in soil physics as well as in geological, geomorphological and sedimentological studies.