In organic farming, crop fertilisation is essentially based on organic fertilisers (e.g. manure) and soil fertility. However, the majority of farms in the Lake Geneva region specialising in field crops have little or no livestock. In this context, the fertilisation of organic crops depends on soil improvers that are not produced on the farm: fertilisers from conventional farms, methanisation products and commercial organic fertilisers.
The aim of this project is to quantify the dependence of a small group of farmers in the French-speaking part of Switzerland on external inputs in order to assess the situation. Subsequently, workshops will be organised to define the ideal crop rotation and associated management practices (tillage, fertilisation, etc.) to best meet the nitrogen needs of the crop while ensuring long-term fertility (carbon sequestration) without exceeding the phosphorus limits of the "Suisse-Bilanz".
