Podzol

The podzol ( from Russian подзол from под pod " under " зола zola " ash ", translated as " ash soil "), even bleaching earth or gray earth called, is an acidic, low in nutrients or impoverished soil type in a damp, cold or humid temperate climate.

• 5.1 Literature

Formation

The genesis of podzols is called podsolization. They are formed from quartz-rich parent rocks such as sandstone, granite or loose, also quartz-rich sands, such as Dune sand. The low content of weatherable minerals leads firstly to a lack of clay minerals on the other hand too low buffering capacity against soil acidification. Due to the low pH, there is a downward displacement ( leaching ) of iron and aluminum hydroxides and humic substances with the leachate from the upper into the subsoil. There are at slightly higher pH, the iron, aluminum or humus compounds reprecipitated or fixed. The result is a faded, heavily depleted surface horizon ( Ae horizon) and a highly enriched with iron compounds and / or humus subsoil horizon (Bs, Bh or Bsh - horizon). The development takes up to 1000 years. The coarse ( water-permeable ) and nutrient-poor podzolic ( little humus in mineral soil ) has because of the low pH to a low soil life. This results in a natural state under forest to a poorly degradable, powerful raw humus layer, which provides due to its low mineralization only in small amounts plant available nutrients. The water- jamming Ortsteinschicht hampered root growth. By liming and intensive use of compost with green and livestock fertilization fertility easily worked podzol can be significantly improved.

Use

In the agricultural sector the podzols are among the poor soils. They are sandy, nutrient-poor and acidic, so have properties that prevent optimal growth of most crop plants. In areas with a high proportion of podzols in the past, the population was often threatened by hunger. For soil improvement is applied in northwestern Germany on such soils the sods, so that the podzols were gradually converted to Plagge ash soils. Today it is possible to uniformly high application of fertilizers and possibly with irrigation, also to do business profitably on podzols. However, since Podsol prone to leaching, there is a risk that fertilizer and pesticides may seep into the groundwater.

Areas with a predominant Podsolanteil such as Outwash plains, or areas with Holocene periglacial or Flugsandsedimentation ( inland dunes ), are now mostly planted with forest.

The podzol was on 5 December 2006 by a Board of Trustees consisting of members of the German Soil Science Society ( DBG ) and the Federation floor (BVB ), appointed to the ground in 2007.

Dissemination

The podzol is the typical soil of the boreal forests in the northern hemisphere and therefore one of the most widespread soil types at all. The low nutrient supply and low pH values ​​have been sufficiently favorable living conditions for coniferous tree species such as pine, spruce and larch the different species. Outside the boreal forest podzols but are also widespread in the temperate mixed forest zone on quartz- rich rocks. Typical Podsolgebiete Central Europe are the Sander and dry glacial valleys of Lower Saxony as well as the large granite and gneiss deposits in the low mountain ranges.

Typical consequences horizon

• Humus ( mor )
• C - source rock

Normpodsol ( Eisenhumuspodsol )

• Ahe - Auswaschungshorizont with mild humus content
• Bsh - humus accumulation horizon with Sesquioxidanreicherung recognizable
• Bhs - Sesquioxidanreicherungshorizont with humus accumulation of recognizable
• C - source rock

Eisenpodsol

• Ahe - Auswaschungshorizont with mild humus content
• Bs - Sesquioxidanreicherungshorizont
• C - source rock

Humuspodsol

• Ahe - Auswaschungshorizont with mild humus content
• C - source rock