Volume 38, Number 3, 2014

Over the past three decades, pedotransfer functions (PTFs) have been widely used by soil scientists to estimate soils properties in temperate regions in response to the lack of soil data for these regions. Several authors indicated that little effort has been dedicated to the prediction of soil properties in the humid tropics, where the need for soil property information is of even greater priority. The aim of this paper is to provide an up-to-date repository of past and recently published […]

The semivariogram provides a visual assessment of spatial dependence but without directly resulting in a single numerical value that expresses the measurement of such dependence. However, from the estimated parameters of the theoretical model adjusted to the experimental semivariogram, it is possible to construct a measure of this spatial dependence. Currently, there are two indices in literature that are widely used; however, these indices show some gaps. The aim of this study was to propose a new index to measure […]

Soil properties have an enormous impact on economic and environmental aspects of agricultural production. Quantitative relationships between soil properties and the factors that influence their variability are the basis of digital soil mapping. The predictive models of soil properties evaluated in this work are statistical (multiple linear regression-MLR) and geostatistical (ordinary kriging and co-kriging). The study was conducted in the municipality of Bom Jardim, RJ, using a soil database with 208 sampling points. Predictive models were evaluated for sand, silt […]

There is a need to evaluate the importance of soil relief together with soil spectral attributes as the basis on soil mapping. The aim of this study was to test a method for detecting soil boundaries through the interaction of spectral data and relief features. Fourteen toposequences were used, representing an area of 13,000 ha near the municipalities of São Carlos and Araraquara, SP, Brazil. The samples were described by the conventional method of chemical and particle size analysis, such […]

Knowledge of the soil water retention curve (SWRC) is essential for understanding and modeling hydraulic processes in the soil. However, direct determination of the SWRC is time consuming and costly. In addition, it requires a large number of samples, due to the high spatial and temporal variability of soil hydraulic properties. An alternative is the use of models, called pedotransfer functions (PTFs), which estimate the SWRC from easy-to-measure properties. The aim of this paper was to test the accuracy of […]

Modern agriculture techniques have a great impact on crops and soil quality, especially by the increased machinery traffic and weight. Several devices have been developed for determining soil properties in the field, aimed at managing compacted areas. Penetrometry is a widely used technique; however, there are several types of penetrometers, which have different action modes that can affect the soil resistance measurement. The objective of this study was to compare the functionality of two penetrometry methods (manual and automated mode) […]

In the State of Rio Grande do Sul, the municipality of Pelotas is responsible for 90 % of peach production due to its suitable climate and soil conditions. However, there is the need for new studies that aim at improved fruit quality and increased yield. The aim of this study was to evaluate the relationship that exists between soil physical properties and properties in the peach plant in the years 2010 and 2011 by the technique of multivariate canonical correlation. […]

Soil physical properties, plant growth, and water availability in the soil are factors that interact in response to changes in soil structure. Knowing how these factors interact in field conditions is of great importance for management of soil compaction for crop yield. In this paper, three levels of soil compaction, with and without irrigation, were assessed in regard to growth and yield of common bean (Phaseolus vulgaris L.). The probability of interaction between soil compaction and irrigation was 88 % […]

There are two main types of penetrometers. In the static one, a rod with a conical tip is introduced continuously and gradually (nearly statically), simultaneously registering the reaction force, which is equal to the soil resistance. The dynamic penetrometer uses the same rod. However, it is introduced through bringing about an impact mass in freefall. Thus, the theory can be treated by Newtonian dynamics so as to obtain dynamic resistance. The aim of the software is to provide a quick […]

The use of mineralogy as a tool for assessment of soil mineral properties is extremely important for understanding the different chemical and physical relationships in the soil. These variables/properties in the identification of sources of suspended sediments may help elucidate the factors and processes that govern the transfer of sediments and pollutants from terrestrial to aquatic systems. The aim of this study was to quantitatively characterize the mineralogy of the soil of the sources and suspended sediments in a watershed […]