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Environmental Correlation and Spatial Autocorrelation of Soil Properties in Keller Peninsula, Maritime Antarctica Rev. Bras. Ciênc. Solo
Moraes,André Geraldo de Lima; Francelino,Marcio Rocha; Carvalho Junior,Waldir de; Pereira,Marcos Gervasio; Thomazini,André; Schaefer,Carlos Ernesto Gonçalves Reynaud.
ABSTRACT: The pattern of variation in soil and landform properties in relation to environmental covariates are closely related to soil type distribution. The aim of this study was to apply digital soil mapping techniques to analysis of the pattern of soil property variation in relation to environmental covariates under periglacial conditions at Keller Peninsula, Maritime Antarctica. We considered the hypothesis that covariates normally used for environmental correlation elsewhere can be adequately employed in periglacial areas in Maritime Antarctica. For that purpose, 138 soil samples from 47 soil sites were collected for analysis of soil chemical and physical properties. We tested the correlation between soil properties (clay, potassium, sand, organic...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Kriging; Geostatistical methods; Soil variability.
Ano: 2017 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832017000100316
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Estimating Sample Size of Soil Cone Index Profiles by Bootstrapping Rev. Bras. Ciênc. Solo
Alesso,Carlos Agustín; Masola,María Josefina; Carrizo,María Eugenia; Imhoff,Silvia Del Carmen.
ABSTRACT Measurements of the soil cone index are widely used to assess soil resistance to root penetration (SR) and to monitor the soil compaction status of agricultural fields. However, soil sampling for SR estimation is a rather challenging task in view of the high spatial and temporal variability of the soil. This study proposed a bootstrapping method to determine the minimum sample size required to estimate the vertical profile of mean soil cone index (CI) values at different levels of precision and confidence. For this purpose, CI data from a Typic Argiudoll under no-tillage before and after chiseling was used. A total of 151 CI profiles were recorded before and after chiseling in a 3,200 m2 (40 × 80 m) no-tillage area at sampling points distributed...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Sampling; Soil resistance; Bootstrap procedure; Soil variability.
Ano: 2017 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832017000100429
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Field determined variation of the unsaturated hydraulic conductivity functions using simplified analysis of internal drainage experiments Scientia Agricola
Villagra,M. M.; Michiels,P.; Hartmann,R.; Bacchi,O.O.S.; Reichardt,K..
Experimentally determined values of unsaturated soil hydraulic conductivity are presented for an Alfisol of the county of Piracicaba, S.P., Brazil. Simultaneous measurements of soil water content and pressure head are made along a 125 m transect within an irrigated field during the internal drainage process. Calculations of the soil hydraulic conductivity were made using the instantaneous profile method (Watson, 1966) and the unit gradient method (LIBARDI et al., 1980). The spatial variability of the soil hydraulic conductivity manifested along the transect indicates the need to develop a field method to measure K(theta) within prescribed fiducial limits, taking into account quantitative evaluation of spatial and temporal variances associated with the...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Soil variability; Hydraulic conductivity.
Ano: 1994 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90161994000100018
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IMPACTS OF WITHIN-FARM SOIL VARIABILITY ON NITROGEN POLLUTION CONTROL COSTS AgEcon
Vandyke, Laura S.; Bosch, Darrell J.; Pease, James W..
The effects of considering variable within-farm soil runoff and leaching potential on costs of reducing nitrogen losses are analyzed for a Virginia dairy. Manure applications may cause nitrogen losses through runoff and leaching because of factors such as uncertain nitrogen mineralization. Farmers can reduce nitrogen control costs by applying manure on soils with less nitrogen loss potential. Ignoring within-farm soil variability may result in overstating the farm's costs of reducing nitrogen losses.
Tipo: Journal Article Palavras-chave: Economic costs; Linear programming; Manure; Nitrogen; Nutrient management; Simulation; Soil variability; Environmental Economics and Policy.
Ano: 1999 URL: http://purl.umn.edu/15139
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Spatial variability of soil physical attributes in integrated production systems in the Amazon region PAB
Feitosa,Izabela de Lima; Passos,Alexandre Martins Abdão dos; Cipriani,Henrique Nery; Oliveira,Marcelo Silva de; Marcolan,Alaerto Luiz; Vasques,Gustavo Mattos.
Abstract: The objective of this work was to analyze the spatial variability of soil physical attributes in integrated production systems and its relationship with the growth and yield of a corn (Zea mays) crop intercropped with palisade grass (Urochloa brizantha). The experiment was carried out in an integrated crop-livestock (ICL) system and in an integrated crop-livestock-forestry (ICLF) system, in a Plinthic Hapludox. The ICLF system was managed in alleys between eucalyptus (Eucalyptus spp.) rows, spaced at 18, 30, and 42 m. Corn grain and forage yields were positively correlated with soil clay and moisture contents, whereas grain yield was negatively correlated with soil penetration resistance. The lowest corn plant heights and grain yields were...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Eucalyptus; Urochloa brizantha; Agronomic efficiency; Precision agriculture; Soil compaction; Soil variability.
Ano: 2019 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2019000100600
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Variability of apparently homogeneous soilscapes in São Paulo state, Brazil: I. spatial analysis Rev. Bras. Ciênc. Solo
Berg,M. van Den; Oliveira,J. B..
The spatial variability of strongly weathered soils under sugarcane and soybean/wheat rotation was quantitatively assessed on 33 fields in two regions in São Paulo State, Brazil: Araras (15 fields with sugarcane) and Assis (11 fields with sugarcane and seven fields with soybean/wheat rotation). Statistical methods used were: nested analysis of variance (for 11 fields), semivariance analysis and analysis of variance within and between fields. Spatial levels from 50 m to several km were analyzed. Results are discussed with reference to a previously published study carried out in the surroundings of Passo Fundo (RS). Similar variability patterns were found for clay content, organic C content and cation exchange capacity. The fields studied are quite...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Soil variability; Systematic sampling; Latosols; Semivariance analysis.
Ano: 2000 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832000000200015
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Variability of apparently homogeneous soilscapes in São Paulo state, Brazil: II. quality of soil maps Rev. Bras. Ciênc. Solo
Berg,M. van Den; Oliveira,J. B..
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 have a high purity for some legend criteria, such as B horizon type (> 90%) and soil texture class (> 80%). The purity for the "trophic character" (eutrophic, dystrophic, allic) was only 55% in Assis. It was 88% in Araras, where many soil units had...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Soil variability; Map quality; Sampling; Latosols.
Ano: 2000 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832000000200016
Registros recuperados: 7
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