Spatial variability of soil chemical properties after coffee tree removal
01/Oct/2009
Assessing the spatial variability of soil chemical properties has become an important aspect of soil management strategies with a view to higher crop yields with minimal environmental degradation. This study was carried out at the Centro Experimental of the Instituto Agronomico, in Campinas, São Paulo, Brazil. The aim was to characterize the spatial variability of chemical properties of a Rhodic Hapludox on a recently bulldozer-cleaned area after over 30 years of coffee cultivation. Soil samples were collected in a 20 […]
Spatial variability of the chemical, physical and biological properties in lowland cultivated with irrigated rice
01/Aug/2009
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 […]
Distribution and uncertainty of acidity of an oxisol under coffee cultivation
01/Aug/2009
With the development of agriculture, the use of new tools for the evaluation of the properties related to plant yields have become essential to improve the management of agricultural systems. The purpose of this study was to use a fuzzy model to investigate, based on soil chemical properties, the propagation of uncertainty of the acidity of a humic Red-Yellow Latosol (Oxisol) under Arabic coffee plantation. The soil was sampled at a depth of 0 – 0.2 m, in a grid, […]
Soil spatial variation and properties as related to Management units in an experimental area of integrated coconut production
01/Dec/2008
The objective of this work was to access spatial variations of soils from experimental plots for integrated coconut production based on the detailed mapping of soils and the construction of contour maps of soil properties. Observations and measurements were formed and samples collected in small trenches and soil profiles. The amount of soil clay from small trenches was evaluated in the field by finger touch feeling. Physical and chemical analyses were performed in all samples. Particle-size-distribution (profiles), Al, Ca and […]
Anisotropy to analyze spatial variability of some spatially referenced soil chemical variables
01/Dec/2008
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. […]
Spatial variability of mineralogical attributes of an oxisol under different relief forms. I – clay fraction mineralogy
01/Dec/2008
The distribution of the clay fraction minerals depends on specific soil-environmental conditions. The study of the relationship between properties of these minerals and specific sites of landscape occurrence is important to understand the relationship between the mineralogy and other soil attributes. This study aimed to evaluate the degree of cristallinity of goethite, hematite, kaolinite and gibbsite and the spatial pattern in an Oxisol under sugar cane for 30 years. In a grid with regular 10 m – intervals, 119 samples […]
Spatial variability of mineralogical attributes of an oxisol under different relief forms. II – correlation between mineralogy and aggregation
01/Dec/2008
Kaolinite, gibbsite, goethite and hematite are the main clay fraction components in Brazilian Oxisols. The abundance of these mineral influence the physical-chemical properties of such soils, which is thought to depend on the relief. This study aimed to characterize the spatial dependence of the crystallinity of kaolinite, gibbsite, goethite and hematite and aggregates of an Oxisol under sugar cane and to assess the spatial correlation between the attributes. In a grid with regular 10 m intervals 119 samples were collected […]
Simulation of water erosion spatial variability in a watershed representative of oxisols in southern Minas Gerais State
01/Oct/2008
Simulation of water erosion spatial distribution is an important tool for soil conservation planning in watersheds, being an important application of the Universal Soil Loss Equation (USLE) using interpolation principles, such as geostatistics. This study aimed to simulate spatial distribution of water erosion in a watershed of the Alto Rio Grande (MG) region, applying geostatistical tools for mapping, considering different land use scenarios. Water erosion was estimated by the USLE applied to grid cells, weighing pedologic units and land use […]
Selection criteria of spatial variability models used in thematical maps of soil physical attributes and soybean yield
01/Apr/2008
Studies on the spatial variability of soil attributes influencing crop productivity are important for the development of new technologies beneficial to agriculture. Geostatistical techniques can be used to evaluate the variability of soil attributes and contribute to soil mapping and management. The purpose of this paper was to evaluate the quality of the theoretical spatial model adjustments according to the Akaike Information and Filiben Criteria, Cross Validation and the maximum value of the log-likelihood function, of the soil humidity, of […]
Spatial variability of chemical attributes of a soil under different uses and managements
01/Dec/2007
The use and management of soil and crop condition the variability of soil attributes directly. This study was conducted in Selvíria-MS, Brazil with the objective of evaluating the spatial variability of pH, potassium (K), calcium (Ca), magnesium (Mg) and base saturation (% BS) in an Oxisol under different use and management conditions. Soil samples were collected in a grid, in regular 2 m intervals, at 64 grid points, at depths of 0.0-0.1 m and 0.1-0.2 m, from areas of: native cerrado vegetation (savannah), […]