African Journal of
Agricultural Research

  • Abbreviation: Afr. J. Agric. Res.
  • Language: English
  • ISSN: 1991-637X
  • DOI: 10.5897/AJAR
  • Start Year: 2006
  • Published Articles: 6578

Full Length Research Paper

Measurement of apparent electrical conductivity of soil and the spatial variability of soil chemical properties by electromagnetic induction

Glecio Machado Siqueira
  • Glecio Machado Siqueira
  • Departamento de Geociências - São Luís (MA), Universidade Federal do Maranhão - Brazil.
  • Google Scholar
Jorge Dafonte Dafonte
  • Jorge Dafonte Dafonte
  • Departamento de Ingeniería Agroflorestal - Lugo (Galicia), Universidad de Santiago de Compostela - Spain.
  • Google Scholar
Antonio Paz Gonzalez
  • Antonio Paz Gonzalez
  • Universidade da Coruña - Facultad de Ciencias - La Coruña (Galicia), Spain.
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Monteserrat Valcarcel Armesto
  • Monteserrat Valcarcel Armesto
  • Departamento de Ingeniería Agroflorestal - Lugo (Galicia), Universidad de Santiago de Compostela - Spain.
  • Google Scholar
Enio Farias de Franca e Silva
  • Enio Farias de Franca e Silva
  • Departamento de Engenharia Agrícola - Recife (Pernambuco), Universidade Federal Rural de Pernambuco - Brazil.
  • Google Scholar
Mayanna Karlla Lima Costa
  • Mayanna Karlla Lima Costa
  • Departamento de Geociências - São Luís (MA), Universidade Federal do Maranhão - Brazil.
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Raimunda Alves Silva
  • Raimunda Alves Silva
  • Departamento de Geociências - São Luís (MA), Universidade Federal do Maranhão - Brazil.
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  •  Received: 05 April 2016
  •  Accepted: 02 June 2016
  •  Published: 29 September 2016

Abstract

The aim of this research is to evaluate the relationship between the measurement of apparent electrical conductivity of soil and its chemical attributes by electromagnetic induction. Geophysics methods used for soil measurement, with electromagnetic induction technique for measuring apparent electrical conductivity of the soil (ECa) is important for soil digital mapping, as it determines soil properties, with which ECa is directly related. The apparent soil electrical conductivity (ECa) was measured by electromagnetic induction with EM38-DD device (Geonics Ltd) at two depths: Vertical dipole (effective depth of 1.5 m- ECa-V) and horizontal dipole (effective depth of 0.4 m - ECa-H) in 6 ha of land located in the Northwest of Spain (Castro de Ribeiras de Lea, Lugo) on several dates. The experimental semivariogram showed that there was a drift for ECa-V and ECa-H data. Soil chemical properties were shown in 23/06/2008 following the sample scheme building by ESAP program (40 spots). At the 40 optimized sampling points, the following soil properties were measured at 0.0 to 0.3 m depth: Organic matter (OM), pH in CaCl2, phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), potential acidity (H+Al), sum of the basis (SB), cation exchange capacity (CEC) and percent of base saturation (V%). The moderate negative correlation coefficient was found between Log ECa-V and organic matter. Both ECa-H and ECa-V exhibited comparatively low correlations with the chemical properties of soil.

 

Key words: EM38-DD, geostatistics, soil management, precision agriculture.