Soil compaction

Soil compaction

Soil compaction occurs when weight of livestock or heavy machinery compresses soil, causing it to lose pore space. Affected soils become less able to absorb rainfall, thus increasing runoff and erosion. Plants have difficulty in compacted soil because the mineral grains are pressed together so as to leave little space for air and water, which are essential for root growth. Burrowing animals also find a hostile environment, because the denser soil is more difficult to penetrate.

The ability of a soil to recover from compaction depends on climate, mineralogy and fauna. Soils with high shrink-swell capacity, such as Vertisols, recover quickly from compaction where moisture conditions are variable (dry spells shrink the soil, causing it to crack). But clays which do not crack as they dry cannot recover from compaction on their own unless they host ground-dwelling animals such as earthworms — the Cecil soil series is an example.

In construction

Increasing the density of soil, along with its side effects of increased strength and decreased permeability, is usually desirable in earthwork construction and below building foundations. Compaction is accomplished by use of heavy equipment. In sands and gravels, the equipment usually vibrates, to cause re-orientation of the soil particles into a denser configuration. In silts and clays, a sheepsfoot roller is frequently used, to create small zones of intense shearing, which drives air out of the soil.

The result of soil compaction is measured by determining the bulk density of the compacted soil and comparing it to a maximum density, e.g. obtained from a Proctor compaction test, to determine the "relative compaction".

In agriculture

Compaction of agricultural soils is a concern to many agricultural soil scientists and farmers, since soil compaction due to heavy field traffic may reduce plant growth. This may be observed clearly in wheel ruts. However, it cannot be stated that all compaction reduces plant growth. The topic is complicated, because it involves the response of the plant to the soil structure and the availability of water. Thus, it requires knowledge about the stress distribution in the soil below the applied load, and knowledge about the resulting soil deformation and shearing.

ee also

* Compactor
* Consolidation (soil)
* Earthwork
* Soil structure

External links

* [http://www.keengrower.com/2007/06/28/soil-compaction-%e2%80%93-not-conducive-to-root-growth/ Soil Compaction and Root Growth]


Wikimedia Foundation. 2010.

Игры ⚽ Нужна курсовая?

Look at other dictionaries:

  • Compaction — may refer to: Soil compaction, for mechanically induced compaction near the ground surface Compaction (geology), part of the process of lithification involving mechanical dewatering of a sediment by progressive loading under several km of… …   Wikipedia

  • Soil — For other uses, see Soil (disambiguation). A represents soil; B represents laterite, a regolith; C represents saprolite, a less weathered regolith; the bottommost layer represents bedrock …   Wikipedia

  • Compaction (geology) — For compaction near the surface, see Soil compaction; for consolidation near the surface, see Consolidation (soil) Compaction (geology) refers to the process by which a sediment progressively loses its porosity due to the effects of loading. This …   Wikipedia

  • Soil morphology — is the field observable attributes of the soil within the various soil horizons and the description of the kind and arrangement of the horizons. [cite book | last = Buol | first = Stanley W. | authorlink = | coauthors = Southard, Randal J.,… …   Wikipedia

  • Soil structure — is determined by how individual soil granules clump or bind together and aggregate, and therefore, the arrangement of soil pores between them. Soil structure has a major influence on water and air movement, biological activity, root growth and… …   Wikipedia

  • Consolidation (soil) — Consolidation is a process by which soils decrease in volume. According to Karl Terzaghi consolidation is any process which involves decrease in water content of a saturated soil without replacement of water by air. [citation needed] In general… …   Wikipedia

  • Cecil (soil) — with the [http://maps.google.com/maps?f=q hl=en geocode= q=http:%2F%2Fsoil science.info%2Fmaps%2FTypic Soil Pedons.kml ie=UTF8 t=h om=1 ll=36.045456, 78.490705 spn=0.029251,0.061669 z=15 typic Cecil pedon] actually located in Franklin County, NC …   Wikipedia

  • Characterisation of pore space in soil — Soil is essential to most animals on the earth. It is a relatively thin crust where an even smaller portion contains much of the biological activity. Soil consists of three different phases. A solid phase (≈ 20%) that contains mainly minerals of… …   Wikipedia

  • Proctor compaction test — The Proctor compaction test and the related modified Proctor compaction test, named for engineer Ralph R. Proctor (1933), are tests to determine the maximum practically achievable density of soils and aggregates, and are frequently used in… …   Wikipedia

  • Dynamic compaction — is a method that is used to increase the density of the soil when certain subsurface constraints make other methods inappropriate. It is a method that is used to increase the density of soil deposits. The process involves of dropping a heavy… …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”