Possible futures of soil-mapping in France

Marc Voltz,Dominique Arrouays,Antonio Bispo,Philippe Lagacherie,Bertrand Laroche,Blandine Lemercier,Anne Richer-De-Forges,Joëlle Sauter,Nathalie Schnebelen

doi:10.1016/j.geodrs.2020.e00334

Abstract

The need for soil data has largely increased worldwide given the growing general concern about the maintenance and recovery of ecosystem resources and services. The development of digital soil mapping (DSM) is often seen as a means for answering this demand. In France, the national soil mapping strategy has been defined in the early 1990s within the Soil Inventory, Management and Conservation Programme (IGCS) and based on conventional soil mapping approaches. Now, small-scale soil map coverage of France has been almost achieved, soil data needs have evolved and DSM approaches have matured. The question therefore arises of what should be the future soil mapping strategy in France so as to foster soil mapping, better answer end-users needs and raise societal concern about soils. To answer this issue, we present in this paper a prospective analysis of the French national soil mapping strategy, which included i) a survey of the needs and difficulties expressed by producers, managers and users of soil data and ii) a foresight study of potential future scenarios for the development of soil mapping that takes advantage of DSM approaches. The survey indicated that soil information needs are high in terms of soil attributes, spatial resolution and accuracy and go beyond the data and maps presently available for France. The survey also showed that DSM methods remain little known outside the academic sector. The foresight study led to two main outputs. The first is to propose two complementary spatial sampling strategies for new data acquisition: i) upgrading the density of observed soil profiles to homogenize the accuracy of 1:250,000 soil maps for France and ii) improving the knowledge of local soil distribution patterns in the French regions by developing detailed mapping of reference areas, representative of the local soil patterns. The second output is a set of four possible scenarios for the development of soil mapping that differ according to the expected level of concern about soils that may exist in France in the future. The comparison of the scenarios led to several recommendations for favouring soil mapping, acquisition of new soil data and dissemination of soil knowledge. The recommendations include awareness raising about soil mapping and its potential for answering many environmental challenges, capacity building of soil surveyors and soil data users for DSM approaches, and improved quality assessment of soil maps to guide users and stimulate new investments of map producers. This certainly involves renewed public support before market development of soil mapping activities can take place and become the main support for soil mapping in France.

Highlights

The need for soil data has largely increased worldwide given the growing general concern about the maintenance and recovery of⁎ Corresponding author at: INRAE, UMR LISAH, 2 Place Viala 34060, Montpellier, Cedex 1, France.especially to the use of data mining approaches and exploitation of many environmental covariates
To compute the number of new profiles, we considered two soil properties whose observation densities were at the extremes of the observation densities of the main soil properties stored in the DoneSol national soil database: organic carbon (OC) and cation exchange capacity (CEC)
We considered two types of criteria: i) those measuring progress in spatial soil knowledge and ii) those expressing the level of appropriation and concern about soil issues by end users and society

Summary

Introduction

The need for soil data has largely increased worldwide given the growing general concern about the maintenance and recovery of⁎ Corresponding author at: INRAE, UMR LISAH, 2 Place Viala 34060, Montpellier, Cedex 1, France.especially to the use of data mining approaches and exploitation of many environmental covariates. The GlobalSoilMap project (Sanchez et al, 2009; Arrouays et al, 2014) and the Global Soil Partnership of FAO have stimulated the application of DSM at national, continental and global scales (e.g., Bui et al, 2006; Odgers et al, 2012; Adhikari et al, 2013; Hengl et al, 2015; Mulder et al, 2016; Viscarra Rossel et al, 2015, Padarian et al, 2017) These initiatives have already led to the production of digital soil maps over whole countries that estimate soil properties or soil classes at fine spatial resolutions ranging between 20 and 200 m. Minasny and McBratney (2016) concluded in their paper about the history and future of DSM that it has shifted from a research phase into operational use

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