Regosols

A regosol (from Greek: " rhegos " = ceiling, cover ) is a shallower soil that forms at an early stage of soil development on lime-free to low lime loose material; this is a classic example sand. The soil type has two horizons, and is in the class R (Ah / C soil) divided. Its abbreviation is RQ.

Emergence and dissemination

Sand is the classic source material for Regosols because others are poor in lime to lime-free unconsolidated materials extremely rare. When it is present on the surface, there is initially only a horizon ( " pure sand " ) ago. Once setting a settlement with plants, resulting in the formation of humus, so that forms on the surface of a second horizon ( " humic sand "). This initial stage is called Lockersyrosem. Once the humus horizon reaches a thickness of about 2 cm, the soil is a regosol. Thus, the soil development but is not complete. In the course of it comes from the weathering of brunification and Verlehmung, so that a B horizon forms and the subsequent stage is reached ( nutrient-poor brown earth ). At the end of soil development is the podzol.

In Central Europe Regosols occur only on young surfaces, as they brown soils in the train of soil development relatively quickly and develop podzols. Longer-term or even permanent Regosols there is only on erosion -prone sites. These are primarily coastal dunes at the stage of Graudüne. In addition Regosols are nowadays generally widely used due to human activity. Primarily on eroded land by inappropriate use. Also material displacements in the course of civil engineering or military training areas with a sandy bottom can be mentioned.

Worldwide Regosols in dry areas with sandy deserts and semi-deserts are widespread. There, they are also often the final stage of soil formation due to the low biomass production and the constant wind erosion.

Leveling

The regosol has loud German soil classification, the leveling Ah / ILC.

• Ah: The surface horizon (A), humic (h). It has a thickness of at least 2 cm and a maximum of 40 cm ( average 10-20 cm). Under agricultural use may also occur the term Ap ( plowed p =).
• ILC: The starting material (C ) is loose ( l) and decalcified to scale-free (i = silicate; ≤ 2 % by weight of lime). In general, it is sand. The material is largely unweathered and has a thickness of at least 30 cm.

In the international soil classification WRB Regosols partly belong to the reference soil group of Arenosols, but mostly for the same group of Regosols.

Properties

Sand can not retain water and nutrients. Therefore Regosols are risk locations for drought stress and nutrient deficiency. Because of the single grain structure of sand, the material is very susceptible to erosion. Advantages of sand are good workability, root penetration, aeration and heating capacity. The pH can vary greatly. On most sands are very low; only on the coasts because of the shells very high. But due to the low nutrient holding capacity of sand results in a rapid decalcification, so that the values ​​decrease with time.

Use

Regosols is arable principle. Due to the characteristics of the sandy starting material ( nutrient levels, low pH values ​​, erodibility and low water holding capacity ) earnings expectations are but slight and uncertain. The annexe cultures are modest requirements ( rye), such that loose, warm soils prefer (asparagus, potatoes) or generalists ( maize). Possible measures to improve agricultural use are eg Irrigation, regular and appropriate fertilization or humus enrichment by organic fertilization (improving retention capacity of nutrients and water). In particular, the anti-erosion must be considered, especially when the present regosol is only formed by erosion.

Sandy soils in central Europe often used forestry ( pine ).

In the dunes of the coasts, a use is neither possible nor appropriate. The dune belt is important for nature conservation and coastal protection.

Other Ah / C soils

In addition to the regosol include three other soil types in the class of Ah / C soils that differ diagnostically especially in the lime content of the starting material:

• The Pararendzina built on marly material ( carbonate content > 2 wt % and < 75 % by mass). Most are unconsolidated materials such as loess.
• The Ranker also forms on lime- or - free material ( carbonate content ≤ 2 % by mass). However, it must be here to hard rock.
• The rendzina located on calcareous materials ( carbonate content ≥ 75 % by mass) such as limestone or gypsum.

• Soil type