Do Andosols occur in the Czech Republic?

Abstract

The aim of this contribution was either to confirm or refuse the supposition that there are soils on the volcanic effusive rocks in the Bruntál district which can be assigned to the referential group of Andosols. The conditions for the genesis of Andosols are described and the diagnostic criteria of the andic process are defined both according to the principles of the WBR/FAO 2006 classification and according to the Slovak MKSPS 2000 classification system. In the Czech classification system, the diagnostics of Andosols has not yet been described or defined because their occurrence on the territory of the Czech Republic has not been confirmed till now. On the Velký Roudný volcanic dome (780 m), samples from two profiles were taken and described: one from below the summit as a sample of forest soil, and the other from the terraced, grass-covered foot of the hill, formerly used as a ploughed land. The samples from the two profiles were processed, and analyses were carried out according to both the classification systems mentioned above. The results of the analyses were subsequently evaluated. It was discovered that both evaluated profiles conformed to most of the diagnostic characteristics of andic development according to both WRB 2006 and the Slovak 2000 classification systems. Both evaluated profiles could be then classified – according to WRB 2006 – as Vitric Andosol (Dystric) and Vitric – Umbric Andosol (Dystric, Colluvic), respectivelly; according to Slovak Classification System as Andic Cambisols. The occurrence of soils with andic development in the Czech Republic was thus confirmed. The conclusion drawn by some authors (eg. in US Taxonomy) that a higher content of volcanic glass and a substrate of andesite type are not an indispensable condition for the creation of soils classified as Andosols was also confirmed. Likewise, according to the WRB criteria, a melanic humus horizon is not a necessary condition. Because of the difficulties in distinguishing the types, the Czech classification system recommends that a humic andic horizon should be evaluated as molic. We assume that in some cases it could be better classified as umbric. A preliminary proposal has been put forward to insert the Andozem soil types in Taxonomic Soil Classification System of the Czech Republic: Haplic Andosol, Vitric Andosol, Lithic Andosol, Umbric Andosol, but the properties and criteria of those soils will have to be defined precisely. One problem which will also have to be resolved is how to allocate the profiles displaying andic properties either to the proposed subtype of Cambic Andosol or to the subtype of Andic Cambisol (outside the referential class of Andsols). This issue is, indeed, not dealt with satisfactorily either by the Slovak system or the worldwide WRB 2006 classification, either.