The Plagge Esch is limited almost exclusively to the area of North- West Germany soil type that was created by a centuries performed Plagge fertilization. Since the formation of this soil is based on human activity, it is in the German soil classification in the Y class belongs ( anthropogenic soils). Its abbreviation is YE.
On World of soil 2012, this soil type was proclaimed by the Federal Association of the German soil and Soil Science Society as a floor of 2013.
Emergence and dissemination
Plagge ash caused by a special management for soil improvement - the Plagge economy. In nutrient-poor sandy soils, which are typical in the space of the Northwest German Geest, formed in medium to high rainfall usually podzols, who are not good arable sites. These areas were shunned by farmers as long as possible. As the population pressure in the Middle Ages from about the year 1000 rose sharply, a domestication of these low-value areas was necessary, and the returns were marginal and insecure.
To ensure the level of income and security and, in the absence of mineral fertilizer, it was necessary to develop other forms of fertilization. In addition to the then usual Dreifelderwirtschaft Plagge the economy was in the area of North- West Germany developed for this purpose. Here, a few village or hofnahe hallways were ( in northern Germany called Esch) regularly with grass or heather sods fertilized. As sods humus ( grass ) is abgestochener called topsoil with parts of the thereon vegetation and litter. The sods were collected at a remote location in the so-called "common land " ( in the Osnabrück country, " Mark " ), first used in the stables for about a year as litter and then brought to the fields with the manure, ash, and kitchen waste.
Through archaeological excavations it is known that Plagge ash soils originated from the 11th century. In Osnabrück region as a main distribution area of Esch soils continued its emergence a first in the 12th and 13th century.
The end of the Plagge economy was suddenly beginning of the 20th century, since the introduction of Minderaldünger end of the 19th century, the labor-intensive work with the sod was unnecessary. At least since the 1930s, the Plagge bat is no longer practiced. Future remains soil type of the Plagge ash under arable use yet received a long time, is in a phase of degradation, since he is no longer actively created. In absence of Plagge economy it will develop under forest in the long run back towards podzol.
Plagge ash worldwide are only very small areas to be found, because their distribution is linked to the former management. More specifically, they are a regional specialty of the north-west German area with a focus to Osnabrück and Cloppenburg. Here they take a large area fractions of up to 20 percent. However, they occur in central Europe to the Ruhr area and in Belgium, the eastern Netherlands and Denmark. In addition, there are analogous deposits in the Orkneys and Shetland Islands some.
Medieval soil erosion
While the ash experienced by Plagge economy a strong appreciation, it came into their surroundings hardly describable damage to the soil. Since the Abstichflächen were constantly disturbed and several years passed for the formation of a humus layer broke, a large reserve of vulgar land was needed for an Esch. The area ratio was depending on the location at about 1:5 to 1:30. After extraction Plagge these soils to erosion were defenseless, so it came to Bodenauswehungen and water damage on a large scale. Due to the soil and nutrient losses a real devastation was set in motion that can be detected up to now. An example is the whole North-West Germany numerous dunes of this medieval erosion phase. In addition to the erosion of the overuse also led to large-scale Verheidung.
The constant supply of material caused a Aufhöhung the ground surface and the emergence of deep humus ash - horizons that have their own name in the German soil classification (E horizon). Raising the floor level was at a rate of about a millimeter per year Plagge economy. A 40 cm mighty E- horizon must therefore have been geplaggt at least 400 years. As always, the same areas were geplaggt, it came time to abrupt changes in altitude ( Esch edges). This can be as long as one meter.
The strange mineral soil often led to a change in the type of soil. About the starting material sand are often found schluffigere areas. The fertilizer value of manure, ash and kitchen waste is detectable even decades after the end of the Plagge Economy: The ash horizons have today a significant increase in nutrients phosphorus ( sand of the podzol: <20 mg P/100 g soil, E - horizon: 400-1000 mg P/100 g soil ) and potassium, the phosphorus with manure from the animals and potassium were supplied with the ashes. The increase of the nitrogen content can no longer be determined because of the rapid washout of this nutritive element.
With the sod so-called artifacts such as brick or ceramic fragments came into the soil. Downright typical is interspersed throughout the E- horizon charcoal from the ashes. Not only the nutrient but also the water balance of the soil has been improved due to the high content of organic matter.
Plagge ash soils have a special importance for archeology as an archive floors. They act like a protective layer overlying layers of culture time ago and very early. For example, the Stone Age artifact of the Venus of Bierden found under a up to 60 cm thick ash layer, offering protection against the destruction by agriculture. Similarly, the bottom ash was active in the Fund Kalkriese region as a possible site of the Varus Battle.
The German soil classification is the only world that Plagge Ash identifies as its own soil type. In it, they belong to the class Y of terrestrial anthropogenic soils. To identify a bottom as Plagge Esch, the combined thickness of the A - and E- horizon must be at least 40 cm. If this area is low powerful, the name occurs as " with ash Edition ".
The leveling is: Ap / I / IIf ...
- Ap: surface horizon (A) under arable use ( p: plowed ). Partial Plagge ash are not used for agricultural purposes. In this case, it is on the surface an Ah horizon ( humus ( h) top shelf). The A horizon is dark - black humus.
- E: E is the actual ash horizon. It was created by the long-standing economic and Plagge is consistently turns dark humus. Stemmed the sods of turf, so the color is brownish, since the organic material was readily decomposable and the mineralization is more advanced ( Brown Ash ). Sods of heath areas, however, resulted in a gray color. In them, the decomposition conditions are worse, so that the humification überwiegte (gray ash ). Forest sod can develop both colors. The E horizon typically includes visible artifacts ( charcoal, Ziegelbröckchen ... ). In the laboratory, a strongly raised phosphorus content must be proven.
- IIf ...: Under the E- horizon of the original buried soil is ( f: fossil). Since it often means different soil material, a layer change ( II) may be present. The ... represent the variable depending on the location of the covered soil horizons. In the upcoming Podsol often these are usually the horizons fae, FBHS, Bv and C ( see also podzol ).
In the international soil classification (World Reference Base for Soil Resources ) Plagge the ash are among the plaggic, hortic or terric Anthrosolen.
Plagge ash are still classical field locations. Because of the high sand content is well drained, nutrient-poor sites. To achieve satisfactory yields a sufficient, regular fertilization is required. The operated for centuries Plagge economy led but a strong appreciation of the sites, which led to a doubling of the estimated land value number and especially to secure income on average. Previously, the classic fruit cultivation of rye.
By localnear layers of ash Plagge this soil type is often gone by overbuilding. In many settlements still have street names such as "Am Esch " or "On the Esch " attention to the former property of these surfaces.
In the 1980s there were in northern Germany a geoscientific research project under the name " Eschprospektion ". Because the Lower Saxony State Office for Soil Research from Hannover and the University of Kiel were involved. With the project were non-destructive archaeological prospection, such as soil resistivity measurements, checked at the mighty ash requirements.
In Lechtingen near Osnabrück is located in the Windmill Lechtingen a " Plagge Esch- Information Center" under construction, which is operated by the University of Osnabrück.