13 results

Variability of apparently homogeneous soilscapes in São Paulo state, Brazil: II. quality of soil maps

M. van Den Berg, J. B. Oliveira

01/Jun/2000

The quality of semi-detailed (scale 1:100.000) soil maps and the utility of a taxonomically based legend were assessed by studying 33 apparently homogeneous fields with strongly weathered soils in two regions in São Paulo State: Araras and Assis. An independent data set of 395 auger sites was used to determine purity of soil mapping units and analysis of variance within and between mapping units and soil classification units. Twenty three soil profiles were studied in detail. The studied soil maps […]

Soil sampling and kriging intensity to characterize soil water storage in a center pivot – irrigated area

A. C. A. Gonçalves, M. V. Folegatti, S. R. Vieira

01/Sep/1999

Irrigation quality has been described by calculated parameters assuming that water storage capacity in soil is a constant. However, this property presents spatial variations. Concern with environmental and economic aspects has led to culture management in specific areas, a fact which requires knowledge of spatial distribution of soil properties. Geostatistics makes possible the identification of the spatial dependence structure and the mapping of a given soil property. The objective of this work was to identify sampling and block kriging intensities, […]

Soil spatial variability of phosphorus, potassium, and organic matter, in relation to management systems

L. da S. Souza, N. P. Cogo, S. R. Vieira

01/Mar/1998

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 […]

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