The optimal interpolation by using the technique of ordinary kriging, based on the regionalised variable theory, is described and illustrated by a case study of the top-soil (depth 0-30cm) CaCO3 and humus content in the 136 pedons at Petrovo polje, located in dalmatinska Zagora. The spatial variability of the CaCO3 and humus content shown by threedimensional diagrams of the kriged estimates and associated standard errors diagrams may be consequence of different geology, topography and hidrology of the area. Reliability diagrams or maps of the kriged estimation errors, migh be useful in locating areas of large errors, to define optimal sampling strategy for different levels of estimation precision. The results of investigation showed that, by using anisotropic semivariogram models, applied geostatistical analysis can be used to improve local estimation precision of the selected soil properties. For this reason, kriging can be recommended, as a convenient tool, for quantitative estimating and mapping of the individual soil properties at unsampled locations.

soil; kriging; semivariograms; regionalized variable theory

Published by University of Zagreb, Faculty of Agriculture, Zagreb, CROATIA
Sponsored by Ministry Science and Education of the Republic of Croatia