Development and spatialization of a soil potential multifunctionality index for agriculture (Agri-SPMI) at the regional scale. Case study in the Occitanie region (France)

Abstract

Europe is faced to a competing demand for areas suitable for agriculture and areas suitable for urban development. To help building the general guidelines necessary for a sustainable development at the regional scale, we developed a soil potential multifunctionality index for agriculture (Agri-SPMI), which used the concepts of soil-based ecosystem services and soil functions. It considered the provision of a physical and chemical habitat for plant growth functions, the retention and transfer of water and pollutants function, and the carbon storage function. Three agricultural land uses were considered in this index: arable lands, perennial crops, and pastures. The assessment of the Agri-SPMI was done over a large territory, using a small set of inherent soil properties available in the French soil survey database at 1:250,000 scale. The output was in the form of two maps, which can be viewed in a GIS software: a map of areas with high Agri-SPMI and a map of the service of food, biomass, and fiber production. The concept of soil multifunctionality allowed highlighting environmental issues related to agriculture and to encourage land planners to take them into account in addition to the agronomic potential of soils. The framework used is fully transferable to other scales, other soil contexts, or other ecosystem services, with adaptation of the soil properties considered.