Abstract :
[en] Nowadays, to ensure sustainable production, it is essential to promote two actors essential to the resilience of our soils: earthworms and microorganisms communities (EMC). Through the ecological functions they perform in soils (decomposition/mineralization of organic matter, stability of aggregates, resistance to biotic or abiotic stresses,…), they contribute to the provision of ecosystem services to mankind (permeability/infiltration of water in soils, erosion control, ultimately primary production,…).
The relationship between EMC is far from being understood: Positive feedbacks would take place during earthworm activity, as changes in microbial biomass and enzymatic activity would amplified during cohabitation. A detailed study of these interactions and how they evolve with a change in agricultural practices is necessary to better understand how to optimize the provision of ecosystem services.
In Wallonia (Belgium), we can see agricultural practices evolving against two intensification gradient : the decrease in the use of synthetic inputs and the decrease in intensive tillage. Therefore, this thesis will focus on 4 agricultural modalities : Organic agriculture, conservation agriculture, organic + conservation agriculture and conventional agriculture.
The objective is to really quantify the contribution of EMC in these different modalities, through the innovative combination of two approaches. Firstly, a factorial approach is divided into two parts: Tests and samplings in partner long term trials and an ex-situ experimentation in mesocosms. Secondly, a systemic approach will integrate the study in
commercial farms and therefore take into account socio-economic variabilities.
Agricultural practices act as filters for the expression of life in soil, resulting in differences in abundance and diversity then translated in the unlike provision of ecosystem services. In 2021, by sampling about 50 agricultural plots, a previous master’s thesis proved this phenomenon for earthworm communities. For the next four years, a PhD will go further, by adding the interaction with microorganisms communities. This poster presents the thesis objectives and the context in which this research takes place. First results from a previous work are also briefly presented.
