Siqueira, Glécio MachadoDafonte Dafonte, JorgePaz González, AntonioVidal Vázquez, EvaValcárcel-Armesto, MontserratGuedes Filho, Osvaldo2018-01-082018-01-082016-09-29Siqueira, Glécio Machado, Dafonte, Jorge Dafonte, González, Antonio Paz, Vázquez, Eva Vidal, Armesto, Monteserrat Valcarcel, & Guedes Filho, Osvaldo. (2016). Spatial soil sampling design using apparent soil electrical conductivity measurements. Bragantia, 75(4), 459-473. Epub September 29, 2016.https://dx.doi.org/10.1590/1678-4499.4450006-8705http://hdl.handle.net/10347/16248Soil sampling is an important stage of digital soil mapping. The objective of this study was to characterize the spatial design of soil sampling using soil apparent electrical conductivity (ECa) and its optimized spatial sampling. For the characterization, it was used the Spatial Simulated Annealing (SSA) technique, incorporated on the software SANOS 0.1, and the method of response surface sampling design on the software ESAP 2.35. The ECa was measured at 1,887 points in an area of 6 ha located in the northwestern region of Spain. The EM38-DD equipment (Geonics Limited 2005) was used at 2 depths: vertical dipole (1.5 m effective measurement depth) and horizontal dipole (0.75 m effective measurement depth). Semivariogram showed trend for ECa in vertical dipole (ECa-V) and ECa in horizontal dipole (ECa-H). Software SANOS 0.1 and ESAP 2.35 were used to obtain the 40-point sampling scheme, using the 2 schemes (SANOS and ESAP). ECa-V estimation values at the 1,887 points were calculated with residual ordinary kriging. The sampling scheme obtained from ESAP was better than with SANOSeng© 2016, The author(s). This is an Open Access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly citedhttps://creativecommons.org/licenses/by/4.0/deed.enGeostatisticsSemivariogramSpatial variabilityOptimizationSoil samplingSpatial soil sampling design using apparent soil electrical conductivity measurementsjournal article10.1590/1678-4499.4451678-4499open access