Soil compaction (agriculture)

Last updated
During the sugar beet harvest in late autumn in very moist soil condition, the lanes of agricultural equipment causes soil compaction of the clay soil. Ernteschaden.jpg
During the sugar beet harvest in late autumn in very moist soil condition, the lanes of agricultural equipment causes soil compaction of the clay soil.

Soil compaction, also known as soil structure degradation, is the increase of bulk density or decrease in porosity of soil due to externally or internally applied loads. [1] Compaction can adversely affect nearly all physical, chemical and biological properties and functions of soil. [2] Together with soil erosion, it is regarded as the "costliest and most serious environmental problem caused by conventional agriculture." [3]

Contents

In agriculture, soil compaction is a complex problem in which soil, crops, weather and machinery interact. External pressure due to the use of heavy machinery and inappropriate soil management can lead to the compaction of subsoil, creating impermeable layers within the soil that restrict water and nutrient cycles. This process can cause on-site effects such as reduced crop growth, yield and quality as well as off-site effects such as increased surface water run-off, soil erosion, greenhouse gas emissions, eutrophication, reduced groundwater recharge and a loss of biodiversity. [4]

Unlike salinization or erosion, soil compaction is principally a sub-surface problem and therefore an invisible phenomenon. [5] Special identification methods are necessary to locate, monitor and manage the problem appropriately.

History and current state

Soil compaction is not a recent issue. Before the beginning of mechanized agriculture, the usage of plough-pans was associated with soil compaction. [6] However, multiple studies have shown that modern farming techniques increase the risk of harmful soil compaction. [7]

The historic data basis for global soil compaction is generally very weak as there are only measurements or estimates for certain regions/countries at certain points in time. In 1991, it was estimated that soil compaction accounted for 4% (68.3 million hectares) of anthropogenic soil degradation worldwide. [8] In 2013, soil compaction was regarded a major reason for soil degradation in Europe (appr. 33 million ha affected), Africa (18 million ha), Asia (10 million ha), Australia (4 million ha), and some areas of North America. [9]

More specifically, in Europe approximately 32% and 18% of the subsoils are highly and moderately vulnerable to compaction respectively. [10]

Mechanism

In healthy, well-structured soils, particles interact with each other forming soil aggregates. The resulting soil structure increases in stability with the number of interactions between soil particles. Water and air fills the voids between soil particles, where water interacts with soil particles forming a thin layer around them. This layer can shield particle–particle interaction thus reducing the stability of soil structure. [11]

Mechanic pressure applied to the soil is counterbalanced by an increase of soil particle interactions. This implies a reduction in soil volume by reducing the voids in between soil particles. [11]

As a consequence water and air is displaced and soil bulk density increases, resulting in a reduced permeability for water and air. [12]

Susceptibility of soil to compaction depends on several factors, which influence soil particle interactions:

Causes

Soil compaction can occur naturally by the drying and wetting process called soil consolidation, [17] [9] or when external pressure is applied to the soil. The most relevant human-induced causes of soil compaction in agriculture are the use of heavy machineries, tillage practice itself, inappropriate choice of tillage systems, as well as livestock trampling.

Use of large and heavy machineries for agriculture often causes not only topsoil but subsoil compaction. Subsoil compaction is more difficult to be regenerated than topsoil compaction. Not only may the weight of machineries i.e. axle load, but also velocity and number of passages affect the intensity of soil compaction. [18] [19] Inflation pressure of wheels and tyres also plays an important role for the degree of soil compaction. [20]

Whether heavy machinery is in use or not, tillage practice itself can cause soil compaction. While the major cause of soil compaction in a tillage activity nowadays is due to machineries, the influence of compaction resulting from lighter equipments and animals to the topsoil should not be neglected. [21] Moreover, inappropriate choices of tillage systems may cause unnecessary soil compaction. [22] It should however be noted that tillage activity could reduce topsoil compaction compared to no tillage activity in the long term. [23]

Significant livestock trampling resulting from livestock farming on meadows and agricultural land is also viewed major cause of soil compaction. [24] This is not affected whether the grazing is continuous or short term, [25] however it is affected by the intensity of grazing. [26]

Effects

On-site effects

Major effects on soil properties due to soil compaction are reduced air permeability and reduced water infiltration. [27] Main physical negative effects to plants are restricted plant root growth in response to the accumulation of the plant hormone ethylene [28] and accessibility of nutrients due to increase in bulk density and reduced soil pore size. [9] This may lead to an extremely dry topsoil and eventually causes soil to crack because the roots absorb water requiring for transpiration from the upper part of the soil where plants can penetrate with their restricted root depth. [20]

Soil chemical properties are influenced by change in soil physical properties. One possible effect is a decrease in oxygen diffusion that causes anaerobic condition. Together with anaerobic condition, increases in soil water saturation can increase denitrification processes in the soil. Possible consequences are an increase in N2O emission, decreases in available nitrogen in soil and reduced efficiency of nitrogen usage by crops. [29] This may cause in an increase of fertilizer use. [9]

Soil biodiversity is also influenced by reduced soil aeration. Severe soil compaction may cause reduced microbial biomass. [30] Soil compaction may not influence the quantity, but the distribution of macro fauna that is vital for soil structure including earthworms due to reduction in large pores. [9] [31]

All these factors affect plant growth negatively, and thus lead to reduced crop yields in most cases. [32] As soil compaction is persistent, loss of crop yield as one of the "soil compaction costs" [33] may lead to a concern of long term economic loss.

Off-site effects

Soil compaction and its direct effects are closely interrelated with indirect off-site effects that have a global impact, visible only in the long-term perspective. Accumulating effects may result in complex environmental impacts contributing to ongoing global environmental issues such as erosion, flooding, climate change and loss of biodiversity in soil. [34]

Food security

Soil compaction causes reductions in crop growth, yield and quality. Locally, these effects may have minor impacts on food security. If one aggregates the losses in food supply due to soil compaction, however, compaction may threaten food security. This is especially relevant for regions that are prone to droughts and floodings. Here, compacted soil may contribute to dry topsoil and increased surface runoff. In addition, climate change can worsen adverse of soil compaction. This is because climate change features events such as heat waves and storms that can increase the risk of droughts and floodings and drainage systems.

Climate change and Energy use

Soil stores greenhouse gases (GHG). It is seen as a major terrestrial pool of carbon. [35] Providing nutrient cycling and filtering services, soil regulates GHG fluxes. The loss of gases from soil to the atmosphere is often enhanced by the influence of soil compaction on permeability and changes in crop growth. When compacted soils are waterlogged or have an elevated water content, they tend to cause methane (CH4) losses to the atmosphere due to an increased bacteria activity. The release of the GHG nitrous oxide (N2O) originates also from microbiological processes in soil and is reinforced by the use of nitrogen fertilizer on arable land. [36]

Furthermore, compacted soil requires an extra energy input. More fuel and fertilizer are used for cultivation compared to uncompacted soil due to restrictions in crop growth resulting from a decreased efficiency in nitrogen use. The production of nitrogen fertilizer is highly energy demanding.

Erosion, Flooding and Surface Water

The reduced permeability of compacted soil can result in local flooding. When water cannot infiltrate, ponding and water logging pose a general risk for soil erosion by water. [37] On compacted soils, wheel tracks are often the starting point for runoff and erosion. Soil erosion is likely to appear on sloping fields or especially hilly land. This might lead to a transfer of sediments [56] . Except for direct negative effects for farmers, the risk of surface runoff close to wheel tracks affects the off-farm environment indirectly, as it for example redistributes "sediment, nutrients and pesticides within the field and beyond". [20] Especially when the risk of surface soil erosion is heightened, eutrophication of surface waters becomes a big problem due to an increased amount of nutrients. [38] On high risk areas, such as wet soils on slopes, applied slurry can runoff easily. This results in a loss of ammonia, which is polluting surface waters, as it creates a lack of oxygen. Leading so to the death of many species, [37] soil erosion caused by compaction is responsible for a decline in habitat quality and therefore species loss.

Groundwater

Another off-site effect can be seen with regard to groundwater. The infiltration rate of grassland soil without traffic is five times higher than on soil with severe traffic. [39] A consequence might be a reduced recharge of groundwater. Especially in dryer regions suffering from a lack of water reserves, this poses a crucial risk. In regions where "the subsoil provides a significant proportion of the water required by crops to meet transpiration demands", [40] often being dependent on agriculture, this danger of compaction is most present.

Moreover, the amount of fertilizer that is used on compacted soils is more than plants can take up. Thus, the surplus of nitrate in soil tends to leach into groundwater resulting in pollution. Due to a declining filter ability of soil, microbial decomposition of pesticides is restrained and also pesticides are more likely to reach groundwater. [37]

Identification methods

Soil compaction can be identified either in the field, the laboratory or via remote sensing. In order to get reliable data and results a combination of different methods is necessary as "there is no single universal method available to identify compact soils". [41]

In the field

Phenomena like waterlogging on the surface or in subsurface layers, visible reduction in porosity and changes of soil structure, soil moisture and soil colour are indicators of soil compaction in the field. [20] A blue-grey soil colour and a smell of hydrogen sulphide can occur in the top soil due to extenuated aeration . An increase in soil strength can be measured with a penetrometer, which is basically a device for measuring the resistance of a soil. Another important indicator of soil compaction is the vegetation itself. By means of patterns of crop growth, pale leaf colours and root growth, it is possible to draw conclusions to the extent of compaction. [41] Especially when trying to identify soil compaction in the field with the measurements mentioned above it has been considered particularly important to make a comparison between potentially compacted soil and uncompacted soil nearby.

In the laboratory

Soil bulk density, pore-size distribution, water permeability and the relative apparent gas diffusion coefficient give a good overview of the permeability of soils to air and water and therefore on the degree of compaction. Since the coarse pores are most important for water infiltration, gas exchange and transport, focusing on them when measuring the porosity and the diffusion coefficient is recommended. [42] Data gained at a laboratory are reliable as long as a certain amount of samples has been analyzed. That is why it is necessary to gather a large number of soil samples throughout the entire sample plot that is of interest.

Remote sensing

Remote sensing helps to recognize alterations of soil structure, root growth, water storage capacities and biological activity. "Detection of these features directly on the surface of bare soil or indirectly by the vegetation lead to identification of this type of degradation." [43] This is especially helpful for large areas. As a prevention of soil compaction remote sensing can model the susceptibility of soils by considering soil texture, slope value, water regime and economic factors like the type of farming or the machinery being used.

Limitations

Soil compaction is often local and depends on many factors that may vary within a few square meters. This makes it very hard to estimate susceptibility of soils to compaction at a large scale. Since methods of remote sensing are not able to identify soil compaction directly there are limitations to identification, monitoring and quantifying, especially on a global scale. Identification methods mentioned above are insufficient for large areas since it is not possible to get a large enough sample size without harming the soil and keeping financial afford to a reasonable level.

Avoidance and mitigation

It takes several decades for a partial restoration of compacted soil and therefore it is extremely important to take active measures in order to regenerate soil functions. [44] Since soil compaction is very hard to identify and reverse, special attention has to be paid on avoidance and alleviation.

Public policy responses

The United Nations General Assembly has agreed to jointly combat land degradation. In particular, member states committed themselves to "use and disseminate modern technology for data collection, transmission and assessment on land degradation". [45]

The European Union addresses soil compaction by means of the Seventh EU Environment Action Programme, which entered into force in 2014. It recognises that soil degradation is a serious challenge and states that by 2020 land is supposed to be managed sustainably in the entire Union. [46]

National governments have regulated agriculture practices in order to mitigate the effect of soil compaction. For instance, in Germany farmers operate under the Federal Soil Conservation Law. The law states that farmers have the obligation of precaution towards soil compaction according to acknowledged good practices. [47] Good practices may vary from case to case, involving a variety of biological, chemical and technical methods.

Biological methods

The introduction of deep rooting plants is a natural way to regenerate compacted soils. Deep rooting crops provide crop induced wetting and drying cycles that crack the soil, break up impermeable layers of soil by root penetration and increase organic matter.[ citation needed ] The zaï technique [48] describes a system planting pits that are being dug into poor soil. These pits, with an average diameter of 20–40 cm and a depth of 10–20 cm, are filled with organic matter then seeded after the first rain of the season. This technique conserves soil, captures water, and gradually rehabilitates the structure and health of the underlying soil. [49] A systematic way to regenerate degraded soil (e.g. compacted soil) in the long run is the transformation of conventional farming to agroforestry. Agroforestry systems aim at the stabilization of the annual yield as well as the healthy maintenance of the ecosystem by combining the cultivation of crop plants and trees on the same site. [ citation needed ]

Chemical methods

Since soil compaction can lead to a reduced crop growth and therefore to a reduced economic yield the use of fertilizer, especially nitrogen and phosphorus, is increasing. This growing demand causes several problems. Phosphor occurs in marine deposits, magmatic deposits or in guano. Phosphor extracted from marine deposits contains cadmium and uran. Both elements can have toxic effects on soil, plants and hence for humans or animals as consumer.

Another opportunity to increase soil fertility besides from using mineral fertilizer is liming. Through liming the pH level and base saturation should be raised to a level more suitable for microorganisms and especially earth worms in the topsoil. Through an increased activity of soil fauna a loosening of the soil and following a higher porosity and improved water and air permeability should be reached. [50]

Technical methods

Technical methods mainly aim to reduce and control the pressure applied on soil by heavy machinery. First, the idea of controlled wheel traffic is to separate the wheeled tracks and area for plant rooting. [51] Expected is a reduction of area compacted by tyres, reducing negative effects on crop growth. In some areas, GIS-based technology was introduced to better monitor and control the traffic paths. [20]

Low tyre pressure is another way to distribute the pressure applied on a greater surface and soften the overall pressure. For an integrated management, computer-based modelling of crop yard for vulnerability to compaction is recommended in order to avoid driving over vulnerable soil. [52]

No tillage may contribute to better soil condition as it conserves more water than traditional tillage, [51] however as tillage is a preparation of crop yard for coming seeding or planting process, no tillage does not necessary give a positive result in all cases. Loosening of already compacted soil layers by deep ripping may be beneficial for plant growth and soil condition.

See also

Related Research Articles

<span class="mw-page-title-main">Tillage</span> Preparation of soil by mechanical agitation

Tillage is the agricultural preparation of soil by mechanical agitation of various types, such as digging, stirring, and overturning. Examples of human-powered tilling methods using hand tools include shoveling, picking, mattock work, hoeing, and raking. Examples of draft-animal-powered or mechanized work include ploughing, rototilling, rolling with cultipackers or other rollers, harrowing, and cultivating with cultivator shanks (teeth).

<span class="mw-page-title-main">Soil erosion</span> Displacement of soil by water, wind, and lifeforms

Soil erosion is the denudation or wearing away of the upper layer of soil. It is a form of soil degradation. This natural process is caused by the dynamic activity of erosive agents, that is, water, ice (glaciers), snow, air (wind), plants, and animals. In accordance with these agents, erosion is sometimes divided into water erosion, glacial erosion, snow erosion, wind (aeolian) erosion, zoogenic erosion and anthropogenic erosion such as tillage erosion. Soil erosion may be a slow process that continues relatively unnoticed, or it may occur at an alarming rate causing a serious loss of topsoil. The loss of soil from farmland may be reflected in reduced crop production potential, lower surface water quality and damaged drainage networks. Soil erosion could also cause sinkholes.

In geotechnical engineering, soil structure describes the arrangement of the solid parts of the soil and of the pore space located between them. It is determined by how individual soil granules clump, bind together, and aggregate, resulting in the arrangement of soil pores between them. Soil has a major influence on water and air movement, biological activity, root growth and seedling emergence. There are several different types of soil structure. It is inherently a dynamic and complex system that is affected by different factors.

<span class="mw-page-title-main">Cover crop</span> Crop planted to manage erosion and soil quality

In agriculture, cover crops are plants that are planted to cover the soil rather than for the purpose of being harvested. Cover crops manage soil erosion, soil fertility, soil quality, water, weeds, pests, diseases, biodiversity and wildlife in an agroecosystem—an ecological system managed and shaped by humans. Cover crops can increase microbial activity in the soil, which has a positive effect on nitrogen availability, nitrogen uptake in target crops, and crop yields. Cover crops may be an off-season crop planted after harvesting the cash crop. Cover crops are nurse crops in that they increase the survival of the main crop being harvested, and are often grown over the winter. In the United States, cover cropping may cost as much as $35 per acre.

<span class="mw-page-title-main">Topsoil</span> Top layer of soil

Topsoil is the upper layer of soil. It has the highest concentration of organic matter and microorganisms and is where most of the Earth's biological soil activity occurs.

<span class="mw-page-title-main">No-till farming</span> Agricultural method

No-till farming is an agricultural technique for growing crops or pasture without disturbing the soil through tillage. No-till farming decreases the amount of soil erosion tillage causes in certain soils, especially in sandy and dry soils on sloping terrain. Other possible benefits include an increase in the amount of water that infiltrates into the soil, soil retention of organic matter, and nutrient cycling. These methods may increase the amount and variety of life in and on the soil. While conventional no-tillage systems use herbicides to control weeds, organic systems use a combination of strategies, such as planting cover crops as mulch to suppress weeds.

<span class="mw-page-title-main">Nutrient management</span> Management of nutrients in agriculture

Nutrient management is the science and practice directed to link soil, crop, weather, and hydrologic factors with cultural, irrigation, and soil and water conservation practices to achieve optimal nutrient use efficiency, crop yields, crop quality, and economic returns, while reducing off-site transport of nutrients (fertilizer) that may impact the environment. It involves matching a specific field soil, climate, and crop management conditions to rate, source, timing, and place of nutrient application.

<span class="mw-page-title-main">Soil fertility</span> The ability of a soil to sustain agricultural plant growth

Soil fertility refers to the ability of soil to sustain agricultural plant growth, i.e. to provide plant habitat and result in sustained and consistent yields of high quality. It also refers to the soil's ability to supply plant/crop nutrients in the right quantities and qualities over a sustained period of time. A fertile soil has the following properties:

Tilth is a physical condition of soil, especially in relation to its suitability for planting or growing a crop. Factors that determine tilth include the formation and stability of aggregated soil particles, moisture content, degree of aeration, soil biota, rate of water infiltration and drainage. Tilth can change rapidly, depending on environmental factors such as changes in moisture, tillage and soil amendments. The objective of tillage is to improve tilth, thereby increasing crop production; in the long term, however, conventional tillage, especially plowing, often has the opposite effect, causing the soil carbon sponge to oxidize, break down and become compacted.

<span class="mw-page-title-main">Soil conservation</span> Preservation of soil nutrients

Soil conservation is the prevention of loss of the topmost layer of the soil from erosion or prevention of reduced fertility caused by over usage, acidification, salinization or other chemical soil contamination.

<span class="mw-page-title-main">Living mulch</span> Cover crop grown with a main crop as mulch

In agriculture, a living mulch is a cover crop interplanted or undersown with a main crop, and intended to serve the purposes of a mulch, such as weed suppression and regulation of soil temperature. Living mulches grow for a long time with the main crops, whereas cover crops are incorporated into the soil or killed with herbicides.

<span class="mw-page-title-main">Agricultural soil science</span> Branch of soil science

Agricultural soil science is a branch of soil science that deals with the study of edaphic conditions as they relate to the production of food and fiber. In this context, it is also a constituent of the field of agronomy and is thus also described as soil agronomy.

Soil biodiversity refers to the relationship of soil to biodiversity and to aspects of the soil that can be managed in relative to biodiversity. Soil biodiversity relates to some catchment management considerations.

The environmental impact of agriculture is the effect that different farming practices have on the ecosystems around them, and how those effects can be traced back to those practices. The environmental impact of agriculture varies widely based on practices employed by farmers and by the scale of practice. Farming communities that try to reduce environmental impacts through modifying their practices will adopt sustainable agriculture practices. The negative impact of agriculture is an old issue that remains a concern even as experts design innovative means to reduce destruction and enhance eco-efficiency. Though some pastoralism is environmentally positive, modern animal agriculture practices tend to be more environmentally destructive than agricultural practices focused on fruits, vegetables and other biomass. The emissions of ammonia from cattle waste continue to raise concerns over environmental pollution.

<span class="mw-page-title-main">Agricultural pollution</span> Type of pollution caused by agriculture

Agricultural pollution refers to biotic and abiotic byproducts of farming practices that result in contamination or degradation of the environment and surrounding ecosystems, and/or cause injury to humans and their economic interests. The pollution may come from a variety of sources, ranging from point source water pollution to more diffuse, landscape-level causes, also known as non-point source pollution and air pollution. Once in the environment these pollutants can have both direct effects in surrounding ecosystems, i.e. killing local wildlife or contaminating drinking water, and downstream effects such as dead zones caused by agricultural runoff is concentrated in large water bodies.

Soil management is the application of operations, practices, and treatments to protect soil and enhance its performance. It includes soil conservation, soil amendment, and optimal soil health. In agriculture, some amount of soil management is needed both in nonorganic and organic types to prevent agricultural land from becoming poorly productive over decades. Organic farming in particular emphasizes optimal soil management, because it uses soil health as the exclusive or nearly exclusive source of its fertilization and pest control.

Controlled traffic farming (CTF) is a management tool which is used to reduce the damage to soils caused by heavy or repeated agricultural machinery passes on the land. This damage and its negative consequences have been well documented and include increased fuel use, poor seedbeds, reduced crop yields and poor soil function in terms of water infiltration, drainage and greenhouse gas mitigation due to soil compaction.

<span class="mw-page-title-main">Soil regeneration</span>

Soil regeneration, as a particular form of ecological regeneration within the field of restoration ecology, is creating new soil and rejuvenating soil health by: minimizing the loss of topsoil, retaining more carbon than is depleted, boosting biodiversity, and maintaining proper water and nutrient cycling. This has many benefits, such as: soil sequestration of carbon in response to a growing threat of climate change, a reduced risk of soil erosion, and increased overall soil resilience.

<span class="mw-page-title-main">Tillage erosion</span> Form of soil erosion

Tillage erosion is a form of soil erosion occurring in cultivated fields due to the movement of soil by tillage. There is growing evidence that tillage erosion is a major soil erosion process in agricultural lands, surpassing water and wind erosion in many fields all around the world, especially on sloping and hilly lands A signature spatial pattern of soil erosion shown in many water erosion handbooks and pamphlets, the eroded hilltops, is actually caused by tillage erosion as water erosion mainly causes soil losses in the midslope and lowerslope segments of a slope, not the hilltops. Tillage erosion results in soil degradation, which can lead to significant reduction in crop yield and, therefore, economic losses for the farm.

<span class="mw-page-title-main">Effects of deforestation on soil erosion in Nigeria</span> Effects of deforestation on soil erosion

Deforestation in Nigeria can be said to be the process of cutting down trees or clearing forests for either agricultural, commercial, residential, or industrial purposes. In Nigeria, it has become an increasingly important environmental concern as it has adverse effects on the ecosystem, including soil erosion.

References

  1. Alakukku, Laura (2012). Soil Compaction. In: Jakobsson, Christine: Ecosystem Health and Sustainable Agriculture 1: Sustainable Agriculture. Uppsala University. URL: www.balticuniv.uu.se/index.php/component/docman/doc_download/1256-chapter-28-soil-compaction- (accessed November 14th 2014).
  2. Whalley, W.R., Dumitru, E. & Dexter, A.R. (1995). "Biological effects of soil compaction". Soil and Tillage Research, 35, 53–68.
  3. FAO (2003). Soil Compaction - an unnecessary form of land degradation. p. 2. URL: http://www.fao.org/ag/ca/doc/Soil_compaction.pdf (accessed November 15th 2014)
  4. Batey, T. (2009). "Soil compaction and soil management – a review". Soil Use and Management. 12 (25): 335–345 [339–340]. doi:10.1111/j.1475-2743.2009.00236.x. S2CID   96618510.
  5. FAO (unknown). Conservation of natural resources for sustainable agriculture: what you should know about it. See page 2. URL: http://www.fao.org/ag/ca/training_materials/cd27-english/sc/soil_compaction.pdf (accessed November 14th 2014).
  6. Batey, T. (2009). Soil compaction and soil management – a review. In: Soil Use and Management, 12, 25, 335-345. See page 335.
  7. Stalham, M.A., Allen, E.J. & Herry, F.X. (2005). Effects of soil compaction on potato growth and its removal by cultivation. Research review R261 British Potato Council, Oxford.
  8. Oldeman, L.R., Hakkeling, R.T.A. and Sombroek, W.G. (1991). World map of the status of human-induced soil degradation. An explanatory note. ISRIC, Wageningen, UNEP, Nairobi.
  9. 1 2 3 4 5 Nawaz, Muhammad Farrakh; Bourrié, Guilhem; Trolard, Fabienne (2012-01-31). "Soil compaction impact and modelling. A review" (PDF). Agronomy for Sustainable Development. 33 (2). Springer Nature: 291–309. doi: 10.1007/s13593-011-0071-8 . ISSN   1774-0746. S2CID   17247157.
  10. B, Fraters (1996-03-31). "Generalized Soil Map of Europe ; aggregation of the FAO-Unesco soil units based on the characteristics determining the vulnerability to degradation processes".{{cite journal}}: Cite journal requires |journal= (help)
  11. 1 2 3 Hartge, Karl Heinrich and Horn, Rainer (1991). Einführung in die Bodenphysik, Enke Verlag. 2. Auflage, p. 25–115
  12. 1 2 Jones, Robert JA and Spoor, G and Thomasson, AJ (2003). Vulnerability of subsoils in Europe to compaction: a preliminary analysis, Soil and Tillage Research. Vol. 73, 1, 131–143.
  13. Saffih-Hdadi, Kim and Défossez, Pauline and Richard, Guy and Cui, Y-J and Tang, A-M and Chaplain, Véronique (2009). A method for predicting soil susceptibility to the compaction of surface layers as a function of water content and bulk density, Soil and Tillage Research. Vol. 105, 1, 96–103
  14. Saffih-Hdadi, K and Défossez, Pauline and Richard, Guy and Cui, Y-J and Tang, A-M and Chaplain, Véronique (2009). A method for predicting soil susceptibility to the compaction of surface layers as a function of water content and bulk density, Soil and Tillage Research. Vol. 105, 1, 96–103
  15. Hamza, MA and Anderson, WK (2005). Soil compaction in cropping systems: a review of the nature, causes and possible solutions, Soil and tillage research. Vol. 82, 2, 121–145.
  16. Nachtergaele, Freddy and Batjes, Niels (2012). Harmonized world soil database. FAO.
  17. Fabiola, N., Giarola, B., da Silva, A. P., Imhoff, S. and Dexter, A. R. (2003). Contribution of natural soil compaction on hardsetting behavior , Geoderma 113 : 95 - 108.
  18. Taghavifar, H. and Mardani, A. (2014). Effect of velocity, wheel load and multipass on soil compaction, Journal of the Saudi Society of Agricultural Sciences 13 : 57 - 66.
  19. Hamza, M. and Anderson, W. (2005). Soil compaction in cropping systems: A review of the nature, causes and possible solutions , Soil and Tillage Research 82 : 121 – 145.
  20. 1 2 3 4 5 Batey, T. (2009). Soil compaction and soil management - a review, Soil Use and Management 25 : 335 - 345.
  21. J. DeJong-Hughes, J. F. Moncrief, W. B. Voorhees, and J. B. Swan. 2001. Soil compaction: causes, effects and control. http://www.extension.umn.edu/agriculture/tillage/soil-compaction/#density-effects. (last accessed: 19.11.2014)
  22. FAO. 2014. Machinery, tools and equipment, 2. Soil tillage in Conservation Agriculture. http://www.fao.org/ag/ca/3b.html (last accessed: 20.11. 2014)
  23. Alvarez, R. and Steinbach, H. (2009). A review of the effects of tillage systems on some soil physical properties, water content, nitrate availability and crops yield in the Argentine Pampas , Soil and Tillage Research 104 : 1 - 15.
  24. Mulholland, B. and Fullen, M. A. (1991). Cattle trampling and soil compaction on loamy sands, Soil Use and Management 7 : 189-193.
  25. Donkor, N. T., Gedir, J. V., Hudson, R. J., Bork, E. W., Chanasyk, D. S. and Naeth, M. A. (2002). Impacts of grazing systems on soil compaction and pasture production in Alberta, Canadian Journal of Soil Science 82 : 1-8.
  26. Mapfumo, E., Chanasyk, D. S., Naeth, M. A. and Baron, V. S. (1999). Soil compaction under grazing of annual and perennial forages, Canadian Journal of Soil Science 79 : 191-199.
  27. Whalley, W., Dumitru, E. and Dexter, A. (1995). Biological effects of soil compaction , Soil and Tillage Research 35 : 53 - 68.
  28. Pandey, Bipin K.; Huang, Guoqiang; Bhosale, Rahul; Hartman, Sjon; Sturrock, Craig J.; Jose, Lottie; Martin, Olivier C.; Karady, Michal; Voesenek, Laurentius A. C. J.; Ljung, Karin; Lynch, Jonathan P.; Brown, Kathleen M.; Whalley, William R.; Mooney, Sacha J.; Zhang, Dabing; Bennett, Malcolm J. (15 January 2021). "Plant roots sense soil compaction through restricted ethylene diffusion". Science. 371 (6526): 276–280. Bibcode:2021Sci...371..276P. doi:10.1126/science.abf3013. PMID   33446554. S2CID   231606782.
  29. Ruser, R., Flessa, H., Russow, R., Schmidt, G., Buegger, F. and Munch, J. (2006). Emission of N2O, N2 and CO2 from soil fertilized with nitrate: effect of compaction, soil moisture and rewetting , Soil Biology and Biochemistry 38 : 263 - 274.
  30. Pengthamkeerati, P., Motavalli, P. and Kremer, R. (2011). Soil microbial activity and functional diversity changed by compaction, poultry litter and cropping in a claypan soil , Applied Soil Ecology 48 : 71 - 80.
  31. Frey, Beat and Kremer, Johann and Rüdt, Andreas and Sciacca, Stephane and Matthies, Dietmar and Lüscher, Peter (2009). Compaction of forest soils with heavy logging machinery affects soil bacterial community structure, European journal of soil biology. Vol. 45, 4, 312-320.
  32. McKenzie, R. H., (2010) Agricultural Soil Compaction: Causes and Management, Alberta Agriculture and Rural Development Research Division, 1,2.
  33. Arvidsson, J. and Håkansson, I. (1991). A model for estimating crop yield losses caused by soil compaction , Soil and Tillage Research 20 : 319 - 332.
  34. O’Sullivan, M.F., Simota C. (1995). Modelling the environmental impacts of soil compaction: a review. Soil& Tillage Research, 35, 69–84. doi:10.1016/0167-1987(95)00478-B
  35. Batjes, N.H., (1996). Total carbon and nitrogen in the soils of the world. European Journal of Soil Science, 47, 151–163. doi: 10.1111/j.1365-2389.1996.tb01386.x
  36. Watson, R.T., Noble, I. R., Bolin, B., Ravindranath, N. H., Verardo D.J., Dokken, D.J. (2000). Land Use, Land-Use Change and Forestry - IPCC Cambridge University Press: Cambridge. http://www.ipcc.ch/ipccreports/sres/land_use/index.php?idp=23 (15.11.2014, chapter 1.2.3)
  37. 1 2 3 Soane, B.D., van Ouwerkerk, C., (1995). Implications of soil compaction in crop production for the quality of the environment. Soil & Tillage Research, 35, 5-22. doi:10.1016/0167-1987(95)00475-8
  38. Vitousek, M. P.; Aber, J. D.; Howarth, R. W.; Likens, G. E.; Matson, P. A.; Schindler, D. W.; Schlesinger, W. H.; Tilman, D. G. (1997). Human Alteration Of The Global Nitrogen Cycle: Sources and Consequences. Ecological Applications, 7, 737–750.
  39. Soane, B.D., van Ouwerkerk, C., (1995). Implications of soil compaction in crop production for the quality of the environment. Soil & Tillage Research,35, 5-22. doi:10.1016/0167-1987(95)00475-8
  40. Batey, T. (2009). Soil compaction and soil management – a review. In: Soil Use and Management, 12, 25, 341.
  41. 1 2 Batey, T.; McKenzie, D. C. (2006). Soil compaction: identification directly in the field. In: Soil Use and Management, June 2006, 22, 123-131. doi: 10.1111/j.1475-2743.2006.00017.x
  42. Frey, B.; Kremer, J.; Rüdt, A.; Sciacca, S.; Matthies, D. and Lüscher, P. (2009). Compaction of forest soils with heavy logging machinery affects soil bacterial community structure, European Journal of Soil Biology 45: 312 - 320.
  43. Gliński, J.; Horabik, J.; Lipiec, J. (Eds.) (2011). Encyclopedia of Agrophysics. Springer Verlag, Hamburg. see page 767.
  44. Schäffer, J. (2012). Bodenstruktur, Belüftung und Durchwurzelung befahrener Waldböden – Prozessstudien und Monitoring. Schriftenreihe Freiburger Forstliche Forschung, Band 53.
  45. United Nations General Assembly (1994). ELABORATION OF AN INTERNATIONAL CONVENTION TO COMBAT DESERTIFICATION IN COUNTRIES EXPERIENCING SERIOUS DROUGHT AND/OR DESERTIFICATION, PARTICULARLY IN AFRICA. URL: http://www.unccd.int/Lists/SiteDocumentLibrary/conventionText/conv-eng.pdf (accessed November 2014)
  46. Decision No 1386/2013/EU of the European Parliament and of the Council of 20 November 2013 on a General Union Environment Action Programme to 2020 ‘Living well, within the limits of our planet’
  47. Bundes-Bodenschutzgesetz vom 17. März 1998 (BGBl. I S. 502). URL: https://www.gesetze-im-internet.de/bbodschg/BJNR050210998.html
  48. Zai-system
  49. "enhanced agricultural productivity".
  50. Schäffer, J.; Geißen, V.; Hoch, R.; Wilpert, K. v. (2001). Waldkalkung belebt Böden wieder. In: AFZ/Der Wald, 56, 1106-1109.
  51. 1 2 Hamza, M. and Anderson, W. (2005). Soil compaction in cropping systems: A review of the nature, causes and possible solutions , Soil and Tillage Research 82 : 121 - 145.
  52. Saffih-Hdadi, K., Défossez, P., Richard, G., Cui, Y.-J., Tang, A.-M. and Chaplain, V. (2009). A method for predicting soil susceptibility to the compaction of surface layers as a function of water content and bulk density , Soil and Tillage Research 105 : 96 - 103.