Soils I - Part 1 - Soil Functions, Threats and Definitions

The "Pedosphere" is the top most part of the lithosphere. It is in touch and in exchange with the Atmosphere (Earth's Atmosphere), the Hydrosphere (soil solution, groundwater, surface waters), the Biosphere (plants, animals, microorganisms) and the Lithosphere (rocky crust of the earth).

Land consumption: Mostly by urbanisation (space for housing, parking, leisure activities). It effects the infiltration capability which results in sealing and therefore poses an increased flood risk.

Soil compaction: Mostly through heavy machinerey in intensively cultivated areas. It results in a reduced groundwater recharge (reduced infiltration capability through compaction/ compression), an increased flood risk as well as the release of toxic gases (e.g. greenhouse gases).

Soil erosion: Caused by inappropriate soil management (e.g. compaction, fully removing vegetation, animal farming). This results in economic damage, water eutrophication and infrastructural damage.

Soil pollution: Many types of pollution affect soils.

1. atmospheric pollution: can be man made (e.g. coal burning, industry, traffic) or natural (e.g. fires, volcanos). Acid Rain.
2. ground or surface water pollution: e.g. arsenic and agricultural products (fertilizers, pesticides, etc), industrial products (gas, oils) and waste (sewage sludge, mining waste)
3. geogenic pollution: naturally occuring toxins in bedrock, e.g. arsenic and cadmium

Pollutants are either inorganic, organic or radioactive.

1. Water balance and aeration (otherwise pollution of the ground water, microorganisms, etc.)
2. Rootability
3. Nutrients and soil organisms in balance
4. Tolerable levels of pollutants for plants and living organisms

1. Soil is not reproducible (extremely slow regeneration)
2. Support for structures (homes, etc.)
3. Sink for pollutants (as long as they are healthy)

► Only an intact soil structure guarantess the functioning of soils. 

Climate, Organisms/ Biota, Relief, Parent Material/ Rocks, Time

1. Solid Phase (soil matrix of mineral phase and humus): 46% (minerals) 4% (humus)
2. Liquid Phase (soil water): 25%
3. Gaseous Phase (soil air): 25%

• fine pores < 0.2 µm (uninhabited)
• medium pores 0.2-10 µm (bacteria, fungi, algae, root hairs, unicellular organisms)
• coarse pores & secondary pores > 10 µm (roots, nematodes, mites, collembola and other fauna)

Fluctuations in temperature, relative humidity and light. Soils are rather cool, humid and dark.

= surface component of the earth that developed from geological materials (lithosphere/ parent material) and dead biomass (biosphere) by physical (e.g. temperature variations), chemical (e.g. atmospheric gases and liquids) and biological (e.g. organisms) processes.

Displaced soil without in situ soil formation.

Weathered rock without biological influence.

Elementary soil unit (1-10 m² with a depth of 0.5-2m).

A company of pedons (few m² - 1000km²).

• same horizon sequence
• same characteristics of the horizons
• not necessarily the same bedrock

! Soil type can also refer to grain size (dt. Bodentyp).

Differentiation within climate zones due to specific influences of relief, water balance, bedrock and age.

Young soils without characteristic profile.

Relief controlled soil sequence (typically a slope).

Soil development over time.

1. Knowledge (soil is not dirt)
2. Precautionary soil protection
3. Coordinated soil monitoring and surveillance (NaBo) (need to understand the long term effects)
4. Sustainable, careful use
5. Remediate polluted soils to such an extent that there is no danger
6. Soil = common property. Whoever uses soil is responsible for its protection
7. Integrity of the soil is ensured by legal standards
8. Soil protection = corporate mandate > improve institutional conditions for soil protection + financial resources
9. Implement soil protection by all actors
10. Important partners in soil protection: spatial planning, agriculture and forestry