Volume 38, Number 1, 2014
Revisiting the S-index for soil physical quality and its use in Brazil
01/Feb/2014
The S-index was introduced in 2004 in a publication by A.R. Dexter. S was proposed as an indicator of soil physical quality. A critical value delimiting soils with rich and poor physical quality was proposed. At present, Brazil is world leader in citations of Dexter’s publication. In this publication the S-theory is mathematically revisited and extended. It is shown that S is mathematically correlated to bulk density and total porosity. As an absolute indicator, the value of S alone has […]
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 […]
Characterization of Histosols in floodplain environments in the northeast region of Brazil
01/Feb/2014
The Histosols are generally associated with Southeastern and Southern regions of Brazil, and there are few studies on the occurrence and effects of the use and agricultural management of these soils in the Northeast. The aim of this paper is to physically, chemically and morphologically characterize six profiles of Histosols from flood plains in the states of Ceara, Rio Grande do Norte and Paraiba, Brazil and correlate their soil properties to the training environment, as well as quantify their carbon […]
Influence of mineral fertilization on edaphic fauna in Acacia auriculiformis (A. Cunn) plantations
01/Feb/2014
Fertilization and/or the accumulation of organic matter from plant residues can influence the composition of soil and litter community. The goal of this study was to evaluate the effects of P and K fertilization on total faunal and nematode faunal composition and richness in plant litter and soil for 360 days in an area reforested with Acacia auriculiformis (A. Cunn), located in the municipality of Conceição de Macabu in the State of Rio de Janeiro. For each treatment (fertilized and […]
Soil quality indicators in a rhodic kandiudult under different uses in northern Parana, Brazil
01/Feb/2014
Sustainable use of soil, maintaining or improving its quality, is one of the goals of diversification in farmlands. From this point of view, bioindicators associated with C, N and P cycling can be used in assessments of land-use effects on soil quality. The aim of this study was to investigate chemical, microbiological and biochemical properties of soil associated with C, N and P under different land uses in a farm property with diversified activity in northern Parana, Brazil. Seven areas […]
Time-space analysis of water balance components in an Oxisol
01/Feb/2014
Monitoring the variables that constitute the soil water balance equation in a farmed field is important for reliably evaluating water deficit periods during the crop cycle, managing irrigation and estimating nutrient losses through leaching. Components of the water balance equation may vary in space and time, and the study of the temporal stability of the spatial variability of these components is essential for determining the observation points in the field (sites) for monitoring soil moisture accurately with reduced effort in […]
Estimation of water percolation by different methods using TDR
01/Feb/2014
Detailed knowledge on water percolation into the soil in irrigated areas is fundamental for solving problems of drainage, pollution and the recharge of underground aquifers. The aim of this study was to evaluate the percolation estimated by time-domain-reflectometry (TDR) in a drainage lysimeter. We used Darcy’s law with K(θ) functions determined by field and laboratory methods and by the change in water storage in the soil profile at 16 points of moisture measurement at different time intervals. A sandy clay […]
Water storage variability in a vineyard soil in the southern highlands of Santa Catarina state
01/Feb/2014
In the subtropical regions of southern Brazil, rainfall distribution is uneven, which results in temporal variability of soil water storage. For grapes, water is generally available in excess and water deficiency occurs only occasionally. Furthermore, on the Southern Plateau of Santa Catarina, there are differences in soil properties, which results in high spatial variability. These two factors affect the composition of wine grapes. Spatio-temporal analyses are therefore useful in the selection of cultural practices as well as of adequate soils […]
Structure and water storage in an Alfisol under cultivated pasture, native forest and eucalyptus in the state of Rio Grande do Sul
01/Feb/2014
Unsuitable management practices have led to soil compaction and degradation of soil structure. Identifying properties that better represent these alterations are important for recovery of soil structure and for recommendation of practices to avoid damage to soil structure. The aim of this study was evaluate the effect of different soil uses on the structure and water properties of an Alfisol. The study was carried out in an Alfisol in the municipality of Butia in the “Serra do Sudeste” physiographic region […]
Influence of field slope and coffee plantation age on the physical properties of a red-yellow Latosol
01/Feb/2014
In modern agriculture, several factors cause changes in the soil physical properties. The time of establishment of a crop (plantation age) and the slope are examples of factors that moderate the impact of mechanized operations on the soil structure. The objective of this study was to analyze the effect of machinery traffic on the physical properties of a Red-Yellow Latosol under coffee plantations with different ages (2, 7, 18, and 33 years) and slope positions (3, 9 and 15 %). […]