Carbon stock map and texture map for CAPV soils.

Maps obtained as part of the LURCARBONTEXT project (KLIMATEK call 2017). Sand, silt and clay maps have been obtained based on 6,736 georeferenced soil analyses. Since the texture is expressed as % of the three classes (sand, clay and silt) and its sum must be 100 %, the additive log-ratio transformation proposed by Aitchison (1982) has been carried out for compositional data. In this way, the adjusted model chosen will consist of a multivariate response model for the transformed sand and clay variables, and the third (lime) will be the result of the difference between 100 % and the sum of the other two. The statistical model used is the Generalised Additive Models (GAM) subject to a softening penalty.The modelling of the organic carbon content in the first 30 cm of mineral soils (Mg C ha-1) of the Basque Country was made with 12,122 georeferenced analytical samples.