Soil apparent electrical conductivity and geographically weighted regression for mapping soil J. M. Terro ´n • J. R. Marques da Silva • F. J. Moral • Alfonso Garcı ´a-Ferrer Published online: 25 January 2011 Ó Springer Science+Business Media, LLC 2011 Abstract To resolve the spatial variation in soil properties intensively is expensive, but such knowledge is essential to manage the soil better and to achieve greater economic and environmental beneﬁts. The objective of this study was to determine whether the soil apparent electrical conductivity (EC a ), alone or combined with other variables, is a useful alternative for providing detailed information on the soil in the Extremadura region of Spain. Apparent soil electrical conductivity was measured and geographically weighted regression was used to characterize the spatial variation in soil properties, which in turn can be used for soil management. This study shows that soil cation exchange capacity, calcium content, clay percentage and pH have a relatively strong spatial correlation with EC a in the soil of the study area. Keywords Soil apparent electrical conductivity (Ec a )  Clay soil  Soil mapping  Site-speciﬁc management J. M. Terro ´n Departamento de Cultivos Extensivos, Centro de Investigacio ´n La Orden-Valdesequera, Consejerı ´a de Economı ´a, Comercio e Innovacio ´n, Junta de Extremadura, 06187 Guadajira, Badajoz, Spain J. R. Marques da Silva (&) Departamento de Engenharia Rural, Instituto de Cie ˆncias Agra ´rias e Ambientais Mediterra ˆnicas (ICAAM), Escola de Cie ˆncias e Tecnologia, Universidade de E ´ vora, Apartado 94, 7002-554 E ´ vora, Portugal e-mail: jmsilva@uevora.pt F. J. Moral Departamento de Expresio ´n Gra ´ﬁca, Escuela de Ingenierı ´as Industriales, Universidad de Extremadura, Avda. de Elvas, s/n, 06071 Badajoz, Spain A. Garcı ´a-Ferrer Departamento de Ingenierı ´a Gra ´ﬁca y Geoma ´tica, E.T.S. Ingenieros Agro ´nomos y Montes, Universidad de Co ´rdoba, Co ´rdoba, Spain 123 Precision Agric (2011) 12:750–761 DOI 10.1007/s11119-011-9218-5