The spatial variability of physical and chemical attributes of Latosols (Oxisols) cultivated with sugarcane was assessed. The study was carried out in a 90 ha area in the surroundings of Jaboticabal, São Paulo State, Brazil (21 º 15 ‘ S and 48 º 18 ‘ W). A 50 m regular grid was projected onto the experimental area. Soil samples were obtained at each 50 m grid point (421 points) from the 0 to 0.20 m and from the 0.60-0.80 m soil layers. Organic matter, pH, P, K+, Ca2+, Mg2+, H + Al, CEC, soil […]

The determination of the soil water retention curve is a fundamental part of the characterization of soil hydraulic properties. Although soil water retention has been studied for a long time, many details on spatial variability of curves and experimental values are not well known. Knowing on this variability allows a better planning of experiments leading to simplification of sampling. The aim of the study was to explore the procedures for the analysis of the soil water retention curve in order […]

The objectives of this study were to use kriging indicators to generate a representation of soil properties expressed by numeric attributes, to assess the uncertainty in estimates, and to model the uncertainty propagation generated by the fuzzy procedures of map algebra. The studied attributes were exchangeable potassium (K) and aluminum (Al) contents, sum of bases (SB), cationic exchange capacity (CEC), base saturation (V), and total sand content (TST), extracted from 222 pedologic profiles and 219 extra samples, located in Santa […]

To design hydraulic structures, a sound estimation of rainfall parameters is necessary, in order to ensure the technical and economical feasibility of the project. Equations to predict intense rainfall are widely used to estimate runoff peak discharge. The difficulty to obtain estimates for sites where no rainfall data are available can be overcome by the interpolation of precipitation data, based on neighboring meteorological stations, through statistical procedures. The objective of this work was to compare the two most accurate statistical […]

Soil heterogeneity is known to cause variability of soil-water storage. Thus intensive sampling is required to characterize its spatial pattern. For irrigation management, it is necessary to measure the soil water content between irrigations. The objectives of this paper are to identify whether spatial patterns of soil water content in sprinkler irrigated area present temporal stability and whether this property presents spatial dependence. Temporal stability of spatial dependence structures and spatial correlation with clay content were studied. A 180 m long […]

Soil spatial variability of phosphorus, potassium, and organic matter was studied in different soils and management systems, in two counties: a) Eldorado do Sul, State of Rio Grande do Sul, Brazil, on a Dark Red Podzolic-Kandiudult (conventional tillage, no-tillage, minimum tillage, and pasture), using a grid sampling of 1 x 1 m and at depths of 0-0.05 and 0.05-0.20 m; b) Passo Fundo, State of Rio Grande do Sul, Brazil, on a Dusky Red Latosol – Hapludox (conventional tillage and […]

The variability of leaf nutrient concentrations (nitrogen, phosphorus, potassium, calcium, magnesium, zinc, copper, manganese, and iron) was assessed in a twelve-year-old orange orchard, cv. Pêra, grown on a dystrophic Yellow Latosol of medium texture plain relief, in Governador Mangabeira, State of Bahia, Brazil, 1990. A transect consisting of 50 trees, spaced four meters apart, was sampled. Twenty leaves were collected from each tree. The leaves were taken from four different points of the crown, opposite two by two, and from […]

With the objective of assisting sampling systems and planning orange experiments, soil variability was assessed in a twelve-year-old orange orchard, cv. Pera, grown on a dystrophic Yellow Latosol of medium texture plain relief, in Governador Mangabeira, State of Bahia, Brazil, 1990. A transect consisting of 50 trees, spaced 4 m apart, was sampled. Soil samples were taken from a fixed point under the tree drip line on the successively fertilized strip. Results showed that only phosphorus and gravimetric soil moisture […]