Recycling urban biowaste through vermicomposting

The aim of the thesis is to optimize the recovery of biowaste and to study the technique of vermicomposting (worm composting) which, through the use of earthworms, transforms organic matter into a richer soil amendment: vermicompost.

The objective of this study is to qualitatively and quantitatively evaluate the effect of vermicompost on soil fertility, biodiversity, and yield in organic farming.

To achieve this objective, two main areas of focus have been defined:

• the study of the quality of vermicompost as an organic soil amendment in the laboratory (area 1)
• and the study of the effect of this compost applied in the field on soil fertility and biodiversity (area 2).

The field trials will also make it possible to compare the effects of different amendments on the quantity and quality of agricultural biomass production.

To this end, a trial will be conducted on an organic farm, where the effects of vermicompost will be compared with those of “conventional” composts and digestates from anaerobic digesters also derived from urban biowaste.

In order to work at the crop system level (the decision-making level for farmers), these amendments will also be combined with other agroecological practices such as reduced tillage and cover crops in order to determine the most efficient practices in organic field crop systems.

Léo Girard mainly studies the relationships between these management practices and biodiversity, all in the context of climate change. This involves agroecology applied to extensive fish farming. The Isara research team works with fish farmers and pond managers to combine fish production with the preservation of the environment and biodiversity.

In the first part, Léo analyzes the effects of certain agro-fish farming practices on the ecological functioning, biodiversity, and productivity of ponds. The objective here is to show that it is possible to reconcile two important services: agroecological fish production and the maintenance of biodiversity.

In the second part, he examines other services that these environments can provide and the role they can play in the context of climate change. To do this, he studies both the influence of this change on biodiversity and the regulatory services provided. Are fish ponds carbon sinks or sources?

All this work is part of the European PONDERFUL project, and the data comes from two fish farming regions, Dombes in France and Midden-Limburg in Belgium.