Scientific output

The “Soil Science” team gathers different disciplines belonging to soil

science: pedology, soil physics and physico-chemistry, microbial ecology, biogeochemistry, remote sensing and digital mapping, micromorphology and image analysis, but also analytical and isotopic chemistry and agronomy. It was created during the last term period by merging the Soil group from EGC (25 permanent staff) and the Soil Organic Matter group from BIOEMCO (5 permanent staff). The team rules 3 technical plateaux of EcoSys: UPLC_MS_MS, radioisotope (14C), stable isotope (13C); a long-term field experiment QualiAgro, included in national networks opened for external use (SOERE-PRO, ANAEE-France) and two patrimonial field trials: “36 parcelles” and Dehérain.

The framework of our research is the role of soils in agroecosystems facing external constraints related to global changes. In line with our project 2013-2018 which focused on soil functions and ecosystem services that soils can provide, our work has been organized around 4 main research lines: (1) Optimizing organic waste recycling in agriculture, (2) Understanding the fate, dispersion and impacts of pesticides and other organic contaminants in agricultural soils, (3) Soil heterogeneities at the porous scale and (4) Soil organic matter dynamics, C storage and its controlling factors at different spatial organization levels. A new line of research was initiated in 2015 targeting the assessment of soils contribution to ecosystem services. Figure 13 shows the links between our different research topics and highlights the importance of the soil organic matter compartment and the coupling between soil processes (physical, chemical and biological) at different spatial and temporal scales.

The team is nationally and internationally recognized in the research fields concerning the agronomic and environmental assessment of OWP recycling, the understanding on SOM dynamics and C storage as well as the regulation of exposure of pesticides in relation to soil management in various cropping systems. We describe below the main approaches and achievements for our four main research lines (RL).

• RL1. Optimizing organic waste recycling in agriculture

• RL2. Pesticides and other organic contaminants

• RL3. Studying soil organic matter dynamics

• RL4. Assessing ecosystem services provided by soils at different spatial scales

Conclusions

Over the last term period, the 3 first research lines have gained in maturity and autonomy. Considering the territory scale as the operational scale to optimize OWP recycling has been put as a research priority and was reinforced. Understanding the exposure of organic contaminants in soils (pesticides and emerging contaminants) were strongly related to the assessment of the environmental performances of a large panel of cropping systems, with a strong focus on practices related to soil organic matter management and OWP recycling. The activities on soil organic matter dynamics, C storage and its controlling factors at different spatial organization levels have ensured a good integration of the colleagues from the former BioemCo unit. The new research line on ecosystem services has emerged over the period and has been consolidated through different projects. This has clearly benefited from the input of works realized within the three research lines but also from methodological work realized on spatial modeling, geomatics and long- term soil evolution.

A significant part of these activities has contributed to the ECOSYS transversal axes with specific links to the organic waste recycling, climate regulation, regulation of environmental compartment quality and also to the integration approaches axis. The Soil team has maintained strong collaboration with the Eco&Phy team on GHG, ammonia, VOC’s produced by OWP input to soils and on pesticide volatilization. We have developed new collaborations with the Ecotox team via several projects connecting the fate and the effect of various contaminants or mixture of contaminants (trace metal and pharmaceuticals, pesticides cocktails) on soil organisms.

Scientific stategy and project

Research lines (RL) for the next years will still concern the understanding and modeling of soil functions in relation to some important ecosystem services provided by soils. Therefore, strong links exist between our research topics and the 4 axes of the Project Unit presented previously (Fig. 27). This concerns the role of soil carbon storage in climate change mitigation and attenuation, the optimization of organic waste recycling in urban, peri-urban and rural territories, the role of soils in the fate and exposure of contaminants such as pesticides and pharmaceuticals residues, the consideration of the distribution of soil properties at different spatial scales in order to better assess the performance of more resilient and sustainable cropping systems. Within each research lines, new research priorities have emerged and will contribute to the unit research project. They are presented below.