Soil functioning indicators (INFOSOL): a methodological approach for developing and assessing dynamic soil functions within the soil protection strategy content

Germeau, Martin [UCL] Alonso, Alice [UCL] Bielders, Charles [UCL] Javaux, Mathieu [UCL] Laloy, Eric [SCK-CEN] Mattern, Samuel [SPW, Départ. Géomatique] Roisin, Céline [RECOSOL] Vanclooster, Marnik [UCL] et al.[show all]

Soils are subjected to multiple pressures which cause their degradation and endanger their ecological, economic, social and cultural functioning. This justifies the development of indicators for driving sustainable soil management strategies and policies. In this context, numerous soil quality indicators are currently available that allow measuring the physical, chemical and biological status of soil. Yet, only few approaches are available for assessing the soil functioning. This study develops and evaluates indicators for the water flux regulation function of soil. The methodological approach encompasses three steps: (i) the definition and measurement of the relevant reference physical properties of the soil (basic indicators) allowing to assess the physical qualities relative to the environmental function mentioned above; (ii) the development and definition of a set of synthetic indicators of soil functioning, based on 2-dimensional simulation of water fluxes using Hydrus 2D/3D, which explicitly considers the soil structural heterogeneity generated by tillage; and (iii) the establishment of relations between the developed synthetic indicators of soil functioning and the more easily measurable basic indicators. We illustrate this approach for two different land cultivation strategies (ploughing and reduced tillage), two soil types (silt loam and sandy loam) and 2 levels of compaction due to traffic.