Spatial distribution of the saturated hydraulic conductivity (k0) is essential in the study of soil erosion and surface runoff. The purpose of this study was to investigate the spatial continuity of the soil hydrologic characteristic k0 in the watershed Alto Rio Grande, state of Minas Gerais, and to map k0 based on geostatistical procedures, using data without and with logarithmic transformation. Exponential and spherical semi-variogram models were fitted to the experimental semi-variograms in two approaches: ordinary minimum square (MQO) and […]

The physical and chemical properties of a soil depend largely on its mineralogical constitution. Even over short horizontal distances, spatial variability may be high, and are best described by classical descriptive statistics associated with geostatistics. The objective of this study was to characterize the spatial variability of clay mineralogical properties of soils from the Guabirotuba formation, in the metropolitan region of Curitiba (PR), by classical descriptive statistics (especially coefficient of variation – CV) and geostatistics to propose more adequate sampling […]

Information on the spatial structure of soil physical and structural properties is needed to evaluate the soil quality. The purpose of this study was to investigate the spatial behavior of preconsolidation pressure and soil moisture in six transects, three selected along and three across coffee rows, at three different sites under different tillage management systems. The study was carried out on a farm, in Patrocinio, state of Minas Gerais, in the Southeast of Brazil (18 º 59 ‘ 15 ” […]

Tillage systems should create adequate conditions for plant development. The objective of this study was to evaluate the density, porosity and penetration resistance of a Yellow Ultisol in the semi-arid region of northeastern Brazil after tilling with four agricultural implements (chisel, tandem disc harrow, offset disc harrow with 0.56 m discs, offset disc harrow with 0.61 m discs) in one, two and three operations, using an area without tillage as control. Data of soil bulk density and porosity were analyzed […]

The chemical analysis of plant tissue is an efficient method to assess the nutritional status. This study aimed to characterize the spatial variability of plant nutrients and soybean yield in an experimental area (120 x 160 m, totaling 1.92 ha) of a Rhodic Hapludox under no tillage for two years. Soybean leaf and grain yield were sampled at 63 points in a regular 20 m grid. Plant nutrient contents (N, P, K, Ca, Mg, Cu, Fe, Mn, and Zn) were determined analyzing the 3rd leaf […]

A very active and influential parameter in the erosive process is the R factor, called rainfall erosivity. This factor is one of the components of the universal soil loss equation. Studies in spatial variability have been conducted in an attempt to define the spatial distribution of the R factor for a given region. This study aimed to calculate the rainfall erosivity (R factor – EI30) to generate spatial maps. The study was conducted in experimental areas of eucalyptus stands in […]

The estimation of non available soil variables through the knowledge of other related measured variables can be achieved through pedotransfer functions (PTF) mainly saving time and reducing cost. Great differences among soils, however, can yield non desirable results when applying this method. This study discusses the application of developed PTFs by several authors using a variety of soils of different characteristics, to evaluate soil water contents of two Brazilian lowland soils. Comparisons are made between PTF evaluated data and field […]

The influence of relief forms has been studied by several authors and explains the variability in the soil attributes of a landscape. Soil physical attributes depend on relief forms, and their assessment is important in mechanized agricultural systems, such as of sugarcane. This study aimed to characterize the spatial variability in the physical soil attributes and their relationship to the hillslope curvatures in an Alfisol developed from sandstone and growing sugarcane. Grids of 100 x 100 m were delimited in a convex and […]

The effectiveness of soil sampling plans may be increased if the spatial variability of soil properties is known and taken into consideration; the factors that determine it should therefore be studied. The objective of this paper was to evaluate the spatial variability of the contents P, K, Ca, Mg, and S in two Oxisols, one very clayey and the other with medium texture, managed in a similar system for eight years, in no-tillage. Soil samples were collected at regular distances […]

Soil properties are closely related with crop production and spite of the measures implemented, spatial variation has been repeatedly observed and described. Identifying and describing spatial variations of soil properties and their effects on crop yield can be a powerful decision-making tool in specific land management systems. The objective of this research was to characterize the spatial and temporal variations in crop yield and chemical and physical properties of a Rhodic Hapludox soil under no-tillage. The studied area of 3.42 […]