# Nitrogen flows in the development of organic agriculture: two scenarios for the future of organic and conventional livestock in France

Fanny Vergely, Aurélie Wilfart, Joël Aubin, Souhil Harchaoui

► To cite this version:

Fanny Vergely, Aurélie Wilfart, Joël Aubin, Souhil Harchaoui. Nitrogen flows in the development of organic agriculture: two scenarios for the future of organic and conventional livestock in France. 75th Annual Meeting of the European Federation of Animal Science (EAAP), EAAP, Sep 2024, Florence (IT), Italy. hal-05224450

HAL Id: hal-05224450

https://hal.inrae.fr/hal-05224450v1

Submitted on 26 Aug 2025

HAL is a multi-disciplinary open access
archive for the deposit and dissemination of sci-
entific research documents, whether they are pub-
lished or not. The documents may come from
teaching and research institutions in France or
abroad, or from public or private research centers.

L'archive ouverte pluridisciplinaire HAL, est
destinée au dépôt et à la diffusion de documents
scientifiques de niveau recherche, publiés ou non,
émanant des établissements d'enseignement et de
recherche français ou étrangers, des laboratoires
publics ou privés.

<figure><img src="image_1.png" /></figure>

Distributed under a Creative Commons Attribution 4.0 International License
Contribution of livestock in organic agriculture development: a study on nitrogen flows in expansion scenarios in France

F. Vergely¹, A. Wilfart¹, J. Aubin¹, S. Harchaoui¹

¹ INRAE, Institut Agro Rennes-Angers, SAS, 35000 Rennes, France, mail : fanny.vergely@inrae.fr

The European Green Deal has established a goal of achieving a minimum of 25% of the EU's agricultural land under organic agriculture (OA) by 2030, compared to 9.9% currently. Nitrogen has been identified as the main limiting factor for the expansion of OA. Biological nitrogen fixation (BNF) by legume crops is the main nitrogen input available to OA supporting the entire OA agri-food system either through crop rotation or livestock integration. However, the contribution of organic and conventional livestock on the growth of OA, influenced by OA regulations, is barely addressed in the scientific literature. Here we examine the role of livestock in OA in the circularity of nitrogen of the agri-food system, in particular from grassland to cropland and its role on the proportion of animal proteins in human diets.

We calibrated the ALPHA nitrogen budget model (Chatzimpiros and Harchaoui, 2023) based on national statistics and survey data to assess current nitrogen flow metabolism at the national scale for the case of France. We simulated various scenarios to achieve the 25% OA target, taking into account key variables including the proportion of ruminant and monogastric, feed composition and feed import, manure management efficiency and crop rotation strategies.

In 2021, French OA demonstrated a 78% nitrogen self-sufficiency, with BNF contributing for 50% of nitrogen inputs. The remaining 22% of external inputs were evenly split between imported feed and conventional manure. The paper presents contrasting nitrogen circularity scenarios for OA that highlight the dynamics between organic and conventional livestock farming in terms of land use, self-sufficiency, food production and protein content in human diet.