Soil Functions

Soils provide many important functions for plants, animals and humans. The most obvious is for supporting growing crops, plants and trees in the wild, on the farm and in our gardens - but there are lots of others too. For example soil is very important as a home, or habitat, for the teeming millions of soil organisms. It is quite amazing how much variety of life exists in soil.

Soil is extremely important as a filter removing pollution from our drinking water and helping to regulate the flow of water through the landscape. Most rainwater ends up moving into the soil before it gets to plant roots, the aquifers or the river!

Soil is also the foundation for our buildings and roads. Houses and schools are built on soil. The type of soil affects how buildings are made!

Soil also protects our history and past - archaeological finds are dug from the soil. Soil plays an important part in the preservation of the earth's history.

Finally, soils are important in the story 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 also helps regulate other greenhouse gases such as nitrous oxide and methane.

The Millennium Ecosystem Assessment (MA) produced in the early 2000s identified 'ecosystem services' as the benefits that people obtain from ecosystems, including provisioning services such as food, water, timber, and fiber; regulating services that affect climate, foods, disease, wastes, and water quality; cultural services that provide recreational, aesthetic, and spiritual benefits; and supporting services such as soil formation, photosynthesis, and nutrient cycling. Humans, while buffered against environmental changes by culture and technology, are fundamentally dependent on the flow of these ecosystem services.

Many of these 'ecosystem services' depend on the functioning of soil - from regulating flood waters, to supporting agriculture and from recreation activities to nutrient recycling. See the Ecosystem Services section for a fuller explanation of how soils relate to each category of service. This section identifies the many and varied soil functions.

All these are important reasons we must understand and look after soil.