Rendzina – Soil of the Year 2018

Rendzinas are soils developed from rocks containing great amount of calcium carbonates (limestone, dolomite, marl and others) or gypsum. These soils varies from other occurs in Poland, primarily the high abundance of calcium (and often magnesium), which gives the unique soil properties and habitat value. Rendzinas are associated with Poland, throughout the world. The name “Rędzina” (formerly used also in the form of “rzędzina”), was promoted by prof. Sławomir Miklaszewski in the interwar period. Nowadays the term „rendzina”, „rendzic” or  „rend-” prefix occurs in almost all soil classification systems all over the world, including US Soil Taxonomy and the international FAO-WRB system. Rendzinas are loamy soils with high water retention in general. As they contains calcium carbonates (or gypsum), its reaction is neutral or slightly alkaline. Rendzinas are biological active soils that contain high amount of stable forms of humus which favorably affects the soil structure and plant vegetation conditions. They are soils with high production potential for agriculture and forestry. However, the value of rendzinas is very diverse, which depends on the depth of the soil profile (to the bedrock), skeletalness (the amount of rock fragments hindering mechanical cultivation), the type of carbonate bedrocks and the presence of other materials admixtures. A larger share of these admixtures, especially quartz sand, can significantly reduce the value of rendzinas. In Poland, there are rendzinas of all developmental stages. Mountain initial rendzinas have only a few centimeters organic or mineral layer lying on solid or fragmented  calcareous bedrock. Proper rendzinas are built with the shallow profile of weathered rock materials and high amount of skeletal fragments, but they have well-formed humus horizon. Brown rendzinas are medium-deep or deep soils, rich in skeletal rock fragments with advanced soil forming processes evidenced by the well-developed cambic horizons. Chernozemic rendzinas have the deepest profiles and the thickest humus horizons, as well as the smallest amount of the skeletal parts. The bonitation value of the proper and the brown rendzinas varies from IIIa to V class, while the value of the deep chernozemic rendzinas could reach even the I or II class. As forest soils, rendzinas form eutrophic habitats of rich multi-species hornbeam forests, fertile beech forests and thermophilous beech forests. The spatial arrangement of rendzinas is correlated with the presence of carbonate rocks outcrops, mostly in southern Poland. In the mountain range rendzinas mainly occur in the Pieniny and the Western Tatra mountains, sporadically also in the Sudetes. However, the largest areas covered with Rendzinas are  in the Kraków-Częstochowa, Kielce, Silesia and Lublin Uplands. Unique gypsum rendzinas might be found in the Nida Basin. In northern Poland occurs specific rendzinas developed from drained limnic calcareous sediments. Large areas of these soils are presented in protected areas – in several National Parks (Ojcowski, Pieniński, Roztoczański, Tatrzański), as well as in landscape parks.  

Materials to download:

Soil of the Year 2018 – poster (pdf)