Pararendzina
The Pararendzina is a type of soil which is in an early stage of bottoming in Marly starting material ( lime content > 2 wt.% And <75%) forms. Solid or loose materials such as pebble or silicate rock , clay marl or loess come into question. The soil type has two horizons and is divided into class R ( Ah / C soils ). Its abbreviation is RZ.
Origin and Distribution
On free surfaces it comes relatively quickly to a settlement with pioneer plants . If a low powerful humic horizon has been formed, the initial stage, the soil formation reaches ( Lockersyrosem for looseness materials or Syrosem on bedrock). As soon as this humus layer is more than 2 cm thick, the class of Ah / C soils is reached, to which the Pararendzina also belongs. However, this does not mean that soil development is over. In the further course the weathering leads to browning and silting , so that a B-horizon is formed and the following stages are reached. In Central Europe the brown earth and / or parabroun earth follows ; under the steppe climates the black earth .
Since marly, massive rocks are rare, pararendzins are almost always on loose material. These are widespread in Central Europe, for example in the loess areas of central and southern Germany and on the ground moraine landscapes covered with marl boulder in northern Germany and in the foothills of the Alps (e.g. Allgäu , Mecklenburg-Western Pomerania and Schleswig-Holstein ).
Nonetheless, naturally occurring pararendzins are not very widespread in Central Europe, as the soil development quickly changes them to later soil stages (e.g. parabrown earth ) and marly loose material seldom adjoins erosion-prone locations. They are most likely to be found on the steep coasts of the southern Baltic Sea , when the clay till there is repeatedly exposed by soil erosion . Due to soil erosion caused by humans, pararendzins are now widespread soils on agricultural land.
Pararendzins can arise naturally in dry areas (e.g. Kaiserstuhl ) through secondary calcareous formation (rise of lime with evaporating water) from calcium-rich and low-silicon igneous rocks .
Leveling
According to the German soil systematics, the Pararendzina has the leveling Ah / eC.
- Ah: The topsoil horizon (A) is humic (h). It has a thickness of at least 2 cm and a maximum of 40 cm. The term Ap (p = plowed) can also appear under agricultural use.
- eC: The starting material (C) is marbled (e; lime content> 2% by weight and <75%). As a rule, it is loess or young moraine attachments. The material is largely unweathered and must be at least 30 cm thick.
In the international soil systematic World Reference Base for Soil Resources (WRB), the pararendzines, depending on the form of the Ah horizon, predominantly belong to the regosols and phaeozemes .
properties
The properties of the Pararendzina are very similar to those of the Rendzina , but are slightly weakened in comparison. This is the reason for the naming (Para (= apparent) Rendzina). The A horizon is because of not very strong decalcification still carbonathaltig generally. As a result, the pH value is usually in the upper range between 5 and 7.
The marly raw material often has a soil type in the area of loamy sand with around 5% clay . Thus, the supply is plants with water and nutrients relatively well. The humus is usually in the form Moder to Mull before -Moder and thus has a relatively good quality. The C / N ratio is tight. The flat humus area is particularly disadvantageous. All in all, the locations are of medium quality.
use
Natural sites cannot be used due to erosion. Otherwise arable farming , grassland (pasture and hay meadows) and forestry ( beeches ) are common.
Other Ah / C floors
In addition to the Pararendzina, three other soil types belong to the class of Ah / C soils, which differ diagnostically mainly in the lime content of the starting material:
- The Ranker arises on hard rock with little or no lime (carbonate content ≤ 2% by mass). Mostly it is sandstone , granite or quartzite .
- The Regosol also forms on low lime or -free material (carbonate content ≤ 2% by mass). However, it must be loose material. This is almost always sand.
- The Rendzina lies on lime-rich materials (carbonate content ≥ 75% by mass) such as limestone or gypsum.
literature
- AD-HOC-AG Soil 2005: Soil Science Mapping Instructions. Published by the Federal Institute for Geosciences and Raw Materials in cooperation with the State Geological Services of the Federal Republic of Germany, 5th edition, Stuttgart 2005
- W. Amelung, H.-P. Blume , H. Fleige, R. Horn, E. Kandeler , I. Kögel-Knabner , R. Kretschmar, K. Stahr , B.-M. Wilke: Scheffer / Schachtschabel textbook of soil science. 17th edition. Heidelberg 2018. ISBN 978-3-662-55870-6 .
- Leitgeb, E., Reiter, R., English, M., Lüscher, P., Schad, P., Feger, KH (Eds.): Forest floors. An image atlas of the most important soil types from Austria, Germany and Switzerland . Wiley-VCH Verlag GmbH, Weinheim 2013, ISBN 978-3-527-32713-3 (387 pages, approx. 270 colored illustrations).