6533b860fe1ef96bd12c2c05

RESEARCH PRODUCT

Study and modelling of the impacts of agricultural practices on the abundance of soil microbial communities: dynamics at the landscape scale

subject

description

Soil Microbial communities play a major role in soil fertility and are important as bioindicators to evaluate the impacts of agricultural practices on soils. The challenge is to promote their use in order to support / accelerate innovation in the agricultural sector. The goal of this thesis was to characterize spatial and temporal dynamics of soil microbialcommunities at the scale of an agricultural landscape in order to create models and propose a Decision Support Instrument (DSI) for stakeholders in the agricultural communities. For this, a multi-disciplinary approach was used combining microbial ecology, environment assessment, spatial computer modeling, associated to a participatory approach which effectively mobilize stakeholders’ knowledge (scientists, agricultural advisors and growers). This study was based on data collected in Fénay agricultural landscape (1200 ha, Dijon, 21, France) where soil microbial communities were characterized in 2011, 2016 and 2019 and farming practices are known since 2004. The variance of soilmicrobial community abundance analysis evidenced the impact of soil physico-chemical characteristics variability and the importance of historical plot management in soil microbial community abundance and agricultural practices. Based on this knowledge, a multi-agent model was created in order to predict the evolution of soil microbial community abundance in the face of changing agricultural practices. Calibration steps were required in order to evaluate soil microbial biomass carrying capacity and growth and determine time impact of agricultural practices depending on the land use, and thus result in a model with good predictive capabilities. A graphical user interface was developedin order to conduct participatory workshops and evaluated the handling of the model by various actors.