Soil quality is the degree to which a soil can perform its soil functions. A soil with ‘high soil quality’ can deliver the desired functions to meet demands, whereas a soil with ‘low soil quality’ delivers functions at sub-optimal rates (LANDMARK Glossary).

Soil functions refer to soil based ecosystem services: an overarching concept referring to one (out of five, following Schulte et al., 2014) elemental aspect of the soil system that contributes to the generation of goods and services ( LANDMARK GLOSSARY).

bullet_box_whitePrimary productivity (white box)

bullet_box_blueWater purification and regulation (blue box)

bullet_box_blackCarbon sequestration and regulation (black box)

bullet_box_greenProvision of functional and intrinsic biodiversity (green box)

bullet_box_purpleProvision and cycling of nutrients (purple box)

If you would like to consult previous literature on soil functions: Haygarth and Ritz, 2009; Creamer and Holden, 2010; Bouma et al., 2012; Rutgers et al., 2012; Schulte et al.,2014.

 

All soils perform these functions simultaneously, but both the extent and the relative composition of this functionality depends upon pedological, physical, chemical and biological soil properties.

 

The LANDMARK team developed a comprehensive science-based framework for understanding and quantifying soil functions. Each soil function has a definition and it is described by a set of attributes visually represented by a DEXi tree.

Colour code Soil functions Definition   PAPER
bullet_box_white Primary productivity The capacity of a soil to produce plant biomass for human use, providing food, feed, fiber and fuel within natural or managed ecosystem boundaries

Key indicators and management strategies report

DEXi Tree
Using data mining techniques to model primary productivity from international long-term ecological research (ILTER) agricultural experiments in Austria

Development of an Agricultural Primary Productivity Decision Support Model: A Case Study in France

 bullet_box_blue Water purification and regulation The capacity of a soil to remove harmful compounds from the water that it holds and to receive, store and conduct water for subsequent use and the prevention of both prolonged droughts and flooding and erosion

 

Key indicators and management strategies report

DEXi Tree
bullet_box_black Climate regulation and carbon  sequestration The capacity of a soil to reduce the negative impact of increased greenhouse gas (i.e., CO2, CH4, and N2O) emissions on climate

 

Key indicators and management strategies  report

DEXi Tree
bullet_box_green Soil biodiversity and habitat provisioning The multitude of soil organisms and processes, interacting in an ecosystem, making up a significant part of the soil’s natural capital, providing society with a wide range of cultural services and unknown services

 

Key indicators and management strategies  report

DEXi Tree
bullet_box_purple Provision and cycling of nutrients The capacity of a soil to receive nutrients in the form of by-products, to provide nutrients from intrinsic resources or to support the acquisition of nutrients from air or water, and to effectively carry over these nutrients into harvested crops

 

Key indicators and management strategies  report

DEXi Tree
 •The elusive role of soil quality in nutrient cycling: a review.

 

Functional Land Management is a conceptual framework for optimising the supply of soil-based ecosystem services, grouped together in these five overarching soil functions, to the demands at a range of spatial scales, with a view to simultaneously meeting agronomic and environmental policy objectives (Schulte et al., 2014; O’Sullivan et al., 2015).

Analogous to the expression Genotype x Environment x Management (G x E x M) approach commonly applied in the field of crop production, soil functionality depends on soil type “S” (i.e. diagnostic features – intrinsic and dynamic ones), environment “E” (climate, weather, slope, land use, etc. ) and soil management “M” acknowledging that soil functions are never uniquely determined by just one of these three factors.

S x E x M

For example, the impact of land use on the relative composition of soil functions may be illustrated as follows (Schulte et al., 2014) :

Soil functions