5 soil functions
editThese are in order of my personal preference:
- Competency Area 1: Basic Soil Properties
- PO 1. Know The Five Soil Functions.
- Soil is a Medium for plant growth or bio-materials production whereby this medium combines with the other soil functions to anchor roots, and allow for the transport of water and nutrients to the root/soil interface.
- Soil is a Habitat for soil organisms, making up more than half of all "life" on the planet. The micro-organisms are mainly responsible for most of the bio-chemical transformations in the soil medium; whereas, the macro-organisms primarily affect physical soil transformations.
- Soil acts as a Biochemical or Nutrient Reactor which absorbs, releases (i.e., desorbs), and transforms inorganic and biochemical compounds such as essential plant nutrients, pesticides, minerals, heavy metals, and numerous other compounds.
- Soil acts as a Hydrologic Buffer which stores (i.e., water holding capacity) and regulates the flow (i.e., drainage) of water in the landscape, allowing for the transport of various inorganic and biochemical compounds within and through the soil medium.
- Soil is a Foundation for the physical support of structures including everything from plants to skyscrapers.
source: https://nrcca.cals.cornell.edu/soil/CA1/CA0101.php
- Functions of Soil in the Global Ecosystem
Soils perform five key functions in the global ecosystem. Soil serves as a:
- medium for plant growth,
- regulator of water supplies,
- recycler of raw materials,
- habitat for soil organisms, and
- landscaping and engineering medium.
note: extensive supporting text.
source: Plant and Soil Sciences eLibrary http://passel.unl.edu/pages/informationmodule.php?idinformationmodule=1130447033&topicorder=3&maxto=7
- Soil Quality for Environmental Health USDA-NRCS
- Nutrient Cycling - Soil stores, moderates the release of, and cycles nutrients and other elements. During these biogeochemical processes, analogous to the water cycle, nutrients can be transformed into plant available forms, held in the soil, or even lost to air or water.
- Water Relations - Soil can regulate the drainage, flow and storage of water and solutes, which includes nitrogen, phosphorus, pesticides, and other nutrients and compounds dissolved in the water. With proper functioning, soil partitions water for groundwater recharge and for use by plants and soil animals.
- Biodiversity and Habitat - Soil supports the growth of a variety of plants, animals, and soil microorganisms, usually by providing a diverse physical, chemical, and biological habitat.
- Filtering and Buffering - Soil acts as a filter to protect the quality of water, air, and other resources. Toxic compounds or excess nutrients can be degraded or otherwise made unavailable to plants and animals.
- Physical Stability and Support - Soil has the ability to maintain its porous structure to allow passage of air and water, withstand erosive forces, and provide a medium for plant roots. Soils also provide anchoring support for human structures and protect archeological treasures.
Source: Soil Quality for Environmental Health USDA-NRCS http://soilquality.org/functions.html
A 6th soil function: Atmospheric modification
editLESSON PLAN: Six Ecosystem Functions of Soil (group skits)
5. Atmospheric modification. Soils breathe! Gases are exchanged between the soil surface and the air. Gases like oxygen and methane are absorbed, while, while gases like carbon dioxide and nitrous oxide are released. The soil provides a valuable carbon sink. The evaporation of soil moisture also affects air temperature and weather patterns.
Source: Soil4Youth http://soilweb.landfood.ubc.ca/youth/ >> https://soil4youth.soilweb.ca/wp-content/uploads/sites/11/2015/05/LessonPlan5-SixEcosystem-Oct2013.pdf
Elements of the Nature and Properties of Soils by Chegg
modifying the atmosphere
Alternative list
edit5 functions of soil
(combines 2 functions, includes 6th respiration/climate change/atmospheric function)
- Support
- Water provision
- Habitat
- Digestion
- Respiration
source: https://www.regenerative.com/magazine/five-functions-soils
Cranfield University Source
editSoil function
- Soils have many important functions. Perhaps the best appreciated is the function to support the growth of agricultural and horticultural crops. .... The soil's natural cycles go a long way in ensuring that the soil can provide an adequate physical, chemical and biological medium for crop growth. ... soil is also essential for maintaining natural and semi-natural vegetation ...
- The soil itself contains million of organisms, the exact nature and role of which we are still trying to determine. Undoubtedly the soil flora and fauna play a vital role in cycles which are fundamental to the ability of the soil to support natural and semi-natural vegetation without additions of fertiliser and other support mechanisms. They breakdown plant debris, take in components from the atmosphere, aerate the soil together with many other functions that make the soil such an important medium. ...
- Soil is increasingly being recognised as playing a fundamental role in the quality and distribution of our water supply. ...
- Related to how water moves through the soil and the absorption properties of soils is the soil's ability to perform an important function in pollution control. ...
- Soil has always been important for the foundation platform of buildings, roads and other communications and never more so. ...
- Soil plays an important part in the preservation of the earth's history. ...
- Finally, soils have been recognised as having a key role in modifying and ameliorating the risks and effects of climate change. Soil organic matter is one of the major pools of carbon in the biosphere and is important both as a driver of climatic change and as a response variable to climate change, capable of acting both as a source and sink of carbon. ... Soils can also act as a source and sink for nitrous oxides and methane, both also important in creating the greenhouse gas effect.
source: Cranfield University https://www.soil-net.com/legacy/advanced/soil_functions.htm
FAO Infographic
editSoil functions: Soils deliver ecosystem services that enable life on earth
(expands beyond the five functions)
- Water purification and soil contaminant reduction
- Climate regulation
- 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 and fuel
- Carbon sequestration
source: http://www.fao.org/resources/infographics/infographics-details/en/c/284478/