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

• Nutrient Cycling
• Habitat for Organisms
• Flood Regulation
• Source of Pharmaceuticals and Genetic Resources
• Foundation for Human Infrastructure
• Provision of Construction Materials
• Cultural Heritage
• Provision of Food, Fibre, Fuel
• Carbon Sequestration
• Water Purification and Soil Contamination Reduction
• Climate Regulation

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%