Continental-Scale Digital Soil Mapping Using European Soil Profile Data: Soil PH

We used a compilation of 12,333 soil pH measurements from 11 different sources to create a quantitative map of estimated soil pH values across Europe using a geostatistical framework based on regression-kriging. We made use of 54 auxiliary variables in the form of raster maps at 1km resolution to explain the differences in the distribution of soil pHCaCl2 and we added the kriged map of the residuals from the regression model. The goodness of fit of the regression model was satisfactory (R2adj = 0.43) and its residuals follow a Gaussian distribution. The map results agree with our previous knowledge about this soil property. The lowest values correspond to the soils developed on acid rock (granites, quartzite¿s, sandstones, etc), while the higher values are related to the presence of calcareous sediments and basic rocks. The validation of the model also shows that our models is quite accurate (R2adj = 0.56). This shows the validity of regression-kriging in the estimation of the distribution of soil properties when a large and adequately documented number of soil measurements are available.

REUTER Hannes Isaak;  RODRIGUEZ LADO Luis;  HENGL Tomislav;  MONTANARELLA Luca; 

2008-08-12

University of Hamburg

JRC45667

https://publications.jrc.ec.europa.eu/repository/handle/JRC45667,