The use of electromagnetic induction to detect the spatial variability of the salt and clay contents of soils

Williams, BG; Hoey, David

doi:10.1071/sr9870021

Cited by 187 publications

(92 citation statements)

References 4 publications

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“…In the USA, EM data have been used to estimate (i) depth to clay pan (Sudduth et al, 1995) and (ii) depositional depth of sand after a large flooding event in the Midwest of the USA (Kitchen et al, 1996). In Australia, average clay content was mapped using an EM38 at the field level in the lower Gwydir valley (Triantafilis et al, 2001a), while Williams and Hoey (1987) used an EM34 to map average clay content to 7 m.…”

Section: Introductionmentioning

confidence: 99%

Mapping clay content variation using electromagnetic induction techniques

Triantafilis

Lesch

2005

Computers and Electronics in Agriculture

183

110

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Section: Introductionmentioning

confidence: 99%

Mapping clay content variation using electromagnetic induction techniques

Triantafilis

Lesch

2005

Computers and Electronics in Agriculture

183

110

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“…Estudos realizados no Sudeste da Austrália demonstraram a alta correlação existente entre a CE e o teor de argila (Williams & Hoey, 1987). Shaw & Mask (2003), ao avaliar o desempenho do sensor VERIS, modelo 3100, na medição da CE de solos ácidos do Tennessee, EUA, sob plantio direto, constataram que a palha que cobre o solo, neste sistema de manejo, não causou impacto significativo nas medições da CE.…”

Section: Introductionunclassified

Mapeamento da condutividade elétrica e relação com a argila de Latossolo sob plantio direto

Machado

Bernardi

Valencia

et al. 2006

Pesq. agropec. bras.

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Resumo -O objetivo deste trabalho foi mapear e avaliar a variabilidade espacial da condutividade elétrica do solo (CE), obtida por meio de sensor de contato de campo, num Latossolo Vermelho distroférrico, sob plantio direto de grãos, e relacionar a CE com os teores de argila medidos pelo método do densímetro, em amostras georreferenciadas de solo. As amostras foram coletadas numa área de 13 ha, por meio de uma grade de 40x40 m e de grades de 20x20 m, 10x10 m e 5x5 m. A continuidade espacial da CE e do teor de argila foi modelada com o uso de semivariogramas. A CE variou de 1,9 a 13,7 mS m -1 , com valor médio de 5,2 mS m -1 e coeficiente de variação de 48%. O mapa interpolado mostrou tendência de aumento da CE com o aumento dos teores de argila. Os coeficientes de determinação foram de 0,78 e 0,77 entre CE e teor de argila, camadas 0-5 e 5-10 cm, respectivamente. O mapa da CE reflete suficientemente a variação espacial dos teores de argila para uso na delimitação de zonas de manejo.Termos para indexação: geoestatística, granulometria, agricultura de precisão, sensores de campo. Electrical conductivity mapping in relation to clay of a Ferralsol under no tillage systemAbstract -The objective of this work was to map and evaluate the spatial variability of the soil electrical conductivity (EC), measured with a contact sensor in a Rhodic Ferralsol under no till grain crops. The values of soil EC were related to soil clay content, measured by the densimetric method in georreferenced samples collected at 0-5 and 5-10 cm, in a 13 ha field. Soil samples were collected using a 40x40 m grid and densed grids of 20, 10 and 5 m spacing. Spatial continuity of EC and of clay content was modeled using semivariograms. Soil EC ranged from 1.9 to 13.7 mS m -1 with an average of 5.2 mS m -1 and coefficient of variation of 48%. The kriged map of soil EC pointed out a tendency of increase where clay levels were higher. Determination coefficients between soil EC and clay content were 0.78 and 0.77, respectively for 0-5 and 5-10 cm depth. The EC map adequatly reflects the spatial variation in soil texture for establishing the limits of management zones.

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“…Techniques for predicting soil salinity from EC a survey data have been discussed by numerous authors, including Williams and Baker (1982), Rhoades et al (1989Rhoades et al ( , 1999, Hendrickx et al (1992), Rhoades (1992Rhoades ( , 1996, and Lesch et al (1995a). Other soil properties that have also been successfully mapped using EC a data include clay content (Williams and Hoey, 1987), depth to clay layers (Doolittle et al, 1994), and moisture content (Sheets and Hendrickx, 1995;Kachanoski et al, 1988). Additionally, yield potential has been shown to be directly related to EC a data in many applications (Jaynes et al, 1993;Sudduth et al, 1995;Kitchen et al, 1999;Johnson et al, 2003).…”

Section: Introductionmentioning

confidence: 99%