ABSTRACT The assessment of spatial variability of environmental variables such as soil properties is important for site-specific management. A geostatistical index that allows quantifying and characterizing the structure of spatial variability is fundamental in this context. Thus, this study aimed to develop a new spatial dependency index, called the Spatial Dependence Measure (SDM) for the spherical, exponential, Gaussian, cubic, pentaspherical, and wave semivariogram models; and comparing it with some of the indexes available in the literature. The SDM is also […]

ABSTRACT: In geostatistical studies, spatial dependence can generally be described by means of the semivariogram or, in complementary form, with a single index followed by its categorization to classify the degree of such dependence. The objective of this study was to construct a categorization for the spatial dependence index (SDI) proposed by Seidel and Oliveira (2014) in order to classify spatial variability in terms of weak, moderate, and strong dependence. Theoretical values were constructed from different degrees of spatial dependence, […]

In analysis of the spatial and temporal variability of the factors inherent to agricultural production, geostatistics is the basis for the application of the concepts of precision agriculture. Thus, this study was developed to evaluate the spatial variability of soil physical and water properties and to delineate homogeneous zones in a vineyard using geostatistical tools. A field experiment was carried out in Petrolina, Pernambuco, Brazil (in the Lower Middle São Francisco Valley) in a grape vineyard, irrigated by microsprinklers. In […]

The use of geostatistical techniques allows detection of the existence of dependence and the spatial distribution of soil properties, thus constituting an important tool in the analysis and detailed description of the behavior of soil physical properties. The aim of the present study was to use geostatistics in assessment of physical properties in a Latossolo (Oxisol) dystrophic under native forest and pasture in the Amazon region of Manicore. Grids with of 70 x 70 m were established in native forest […]

In the areas where irrigated rice is grown in the south of Brazil, few studies have been carried out to investigate the spatial variability structure of soil properties and to establish new forms of soil management as well as determine soil corrective and fertilizer applications. In this sense, this study had the objective of evaluating the spatial variability of chemical, physical and biological soil properties in a lowland area under irrigated rice cultivation in the conventional till system. For this […]

Studies on soil fertility mapping based on geostatistics should consider some spatial variability characteristics such as spatial continuity and absence of anisotropy. The present study reports an anisotropic analysis of the spatial variability of the following soil chemical variables: iron (Fe), potential acidity (H + Al), organic matter (OM) and manganese (Mn) of a data set of 128 plots without local chemical management, spatially referenced, studied between 1998 and 2002 in a dystrophic Red Latosol (Oxisol), in Cascavel, Paraná, Brazil. […]

The commom practice of burning the sugar cane plant straw before harvesting has been the subject of very intensive discussions related to the possible changes on soil properties as well as the emission of gases in the atmosphere. The objective of this study was to evaluate variations in soil physical and chemical properties of two areas of Cambisols (Inceptisols) cultivated with sugarcane, on of which area was submitted to continuous cultivation and the other was in its 50th

The spatial variability of soil chemical attributes was evaluated in a commercial plantation under conventional soil tillage in Uberlândia, state of Minas Gerais, Brazil, in 2004. The sampling grid was the Santa Rosa Farm, where the soil is classified as very clayey Red Latosol (680 g kg-1 clay). The objective was to evaluate the spatial distribution and dependence of the soil chemical attributes in a plantation under conventional soil tillage. For this purpose, soil data were collected from a grid […]

The soil particle-size distribution has great influence on the plant yield. In the 2002/2003 growing season, plant and soil attributes of an experimental station of the Faculdade de Engenharia/UNESP (Ilha Solteira/SP – Brazil) were analyzed: common bean grain yield (GP), straw yield (SP), clay content (CL), silt (SI) and sand (SA) of a Red Latosol (Oxisol) under no-tillage. The objective was to analyze the variability of the evaluated attributes to characterize spatial dependences and to study linear and spatial correlations […]

Knowledge on spatial dependence characterization of plant and soil properties can help plan and optimize research studies, and be used for commercial agricultural cultivation aiming at precision agriculture. The objective of this study was to evaluate the spatial variability and dependence of several chemical soil properties and of corn yield on a sandy loam Paleudalf. The area was treated with lime and phosphorus by plowing the fertilizers into the soil along with oat residues two months prior to soil sampling. […]