Soil quality is an account of the soil’s ability to provide ecosystem services by performing a range of functions under changing conditions (Tóth et al., 2007).

The term soil functions refers 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).

Soil functions which are present in agro-ecosystems are:

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)

(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 worked in the past month in order to develop a comprehensive science-based framework for understanding and quantifying soil functions. The first accomplished step was to describe the soil functions with initial definitions as follow:

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
 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
bullet_box_black Carbon sequestration and regulation -The capacity of a soil to reduce the negative impact of increased greenhouse gas (i.e., CO2, CH4, and N2O) emissions on climate
bullet_box_green Provision of functional and intrinsic biodiversity -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
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

If you want to learn more consult our LANDMARK GLOSSARY.

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