Soil compaction
Of soil compaction is used when it is therefore by applying a high load to a deformation and a change in the three-phase system ground.
At relatively low applied load raises a reversible ( elastic ) deformation, which springs back to its initial state after the completion of the load again. If there is a load on the point of the preload, then shows a plastic deformation, which is not reversible and thus not fully spring back to its original state. Thus, it is mainly used for the crossing of the preload to a shearing of the soil particles against each other and a Einregelung this with an increase in the solid phase with a simultaneous decrease of the liquid and gaseous phase.
Agriculture and Forestry
Problems of soil compaction arise primarily in agriculture, as well as in forestry, where show particularly negative aspects. These soil compaction may be partly caused by the use of very heavy machinery in adverse (wet) soil conditions. Decreases in air conductivity, water conductivity and increases the preload, the shear parameters, storage density can be detected.
On the other hand, are the reasons for the increasing compaction of agricultural soils not only in the burden of the axle loads, justified in driving over or the wrong tire choice. Is shown by the small successes that are achieved today with the mechanical loosening or the use of wide tires. The soils compress very quickly. In many cases, humus loss and a greatly reduced soil life due to ever-tightening crop rotations, lack of catch crops and lack of organic matter ( SOM ) (eg manure or compost doses ) the reason for an increasing soil compaction.
Especially serious, the problem of sub- soil compaction has been shown below the plow sole on agricultural land. In addition to the reduced water and air supply ( ascendant as well dezendent ) for plants and microorganisms also makes an increased penetration of plant roots a management increasingly problematic.
In addition, iron toxicity can be felt. Iron is an essential trace element in plant organisms, where it influences photosynthesis and the formation of chlorophyll and carbohydrates. In the soil, it is in the normal pH values of Fe (OH) 3 before. With a low oxygen content of the soil Fe (III) by reduction to Fe (II) is reduced. Thus, the iron is placed in a soluble form for plant available. If this availability under anaerobic conditions, for example by soil compaction, too much, plant damage can occur due to iron toxicity, a phenomenon which is known particularly in rice-growing areas.
While there are appropriate measures to counteract these condensations, such as the use of Terra tires, no-tillage or mechanical easing, but a regeneration of soil damage takes place under natural conditions, if at all, only very slowly instead.
As a result of soil compaction can in heavy precipitation to increased surface runoff and thereby come to increase the erosion of the soil. The reduced storage capacity of the soil favors flood events. The entry of rainwater into the groundwater body is reduced, increasing the risk of lowering the groundwater table is created. Waterlogging can lead to a significant loss of nitrogen in the soil, as in wet soil amplifies the greenhouse gas nitrous oxide is formed. The overall deterioration in growth conditions can eventually also lead to an increase of the fungal infection and Aufschießens of weeds, which may lead to the increased use of chemical pesticides on crops after. In addition, the growth period of the plants can shorten in wet and therefore relatively cool soils and heavy soils to be processed require a higher fuel use in agricultural machinery.
Soil compaction in lawns lead to holes in the turf, especially when cars were parked on the lawn. Nachzusäen here is difficult; when solid ground and thus holes in lawns, so only helps a thorough digging up the affected area.
For the review of the causes of soil compaction, the method of spades diagnosis is particularly well suited.
Construction
While soil compaction applies in the agriculture and forestry generally considered undesirable, this is in the construction industry often a necessity dar. Here road rollers, vibratory plates, vibratory rammers, for example, etc. used to obtain a stable base for works or building and a professional to allow establishment.
Mining
In the reclamation of old opencast mines the edges of the sides shall be sometimes condensed to avoid setting the flow. This is the permanent slope protection for groundwater rebound and is particularly common in the Lusatian mining area.
Generally, a hole is drilled with a drilling in the layers to be compressed and ignited a defined explosive charge. This causes a local change in the bulk density.
Literature ( Agriculture and Forestry )
- Best, A. ( 2005): Agricultural land protection in practice. Foundations, analysis, management. Preservation of soil functions for production, water conservation and flood prevention.
- Best, A. ( 2006): How much water can hold my ground during heavy rain? How much dryness begins on my floor? Improve soil functions and increase soil fertility using the qualitative analysis of the soil. Guide for practitioners. 35 pages with color illustrations, including CD -ROM with sample images
- Günter Fellberg: chemical pollution, 3rd edition, Verlag BG Teubner, Stuttgart 1997, ISBN 3-519-23510-2
- Handbook of Soil Science ISBN 3-609-72210- X
- Manual of soil conservation ISBN 3-609-65853-3
- Robert Bosch Foundation, ed (1994 ): Schwäbisch Hall Farm colloquium on land use, soil functions and soil fertility. Memorandum for an environmentally friendly land use in agriculture. Gerlingen
- Heavy load on the field. In: Scientific American 8/2006, pp. 80-88