Mitigating and adapting to climate change through the introduction of legumes in Occitanie (MACHICOULIS)

Context and challenges

By 2050, southern European regions, such as Occitanie in France, will be confronted with greater variability in precipitation and an increase in temperatures and heat waves. At the same time, population growth could lead to increased pressure on the water resources available for irrigation.

Legumes have a number of agronomic, environmental and nutritional properties to help agri-food systems adapt to and mitigate climate change. Increasing the production and consumption of legumes can contribute to reducing the carbon footprint by avoiding direct GHG emissions thanks to the manufacture and application of nitrogenous fertilisers and imports of plant proteins for animal feed, but also indirect emissions through the substitution of animal proteins in human food. They can reduce the sensitivity of cropping systems to climatic hazards by shifting or reducing water requirements in the summer period (e.g. by substituting summer crops with winter legumes). Nutritionally, in addition to their high protein content, legumes are an important source of fibre and micronutrients that are beneficial to health.

© Marie-Benoit Magrini

Increasing the production and consumption of grain legumes for human consumption appears to be a key lever for a sustainable transition of agri-food systems. Given that the services provided by legumes may differ according to the production area allocated, the species grown, the cropping methods (pure or associated, types of crop succession), and the targeted markets (human or animal consumption), the ex-ante evaluation of the scenarios for the development of legumes and their use in food and feed systems (GHG mitigation, water use, meeting protein needs for human and animal consumption) seems to be an important research priority to promote the production of legumes and contribute to climate change adaptation and mitigation. The Occitanie region, where legume production has been on the rise in recent years, is an interesting case study.

Goals

The MACHICOULIS project proposes to develop an interdisciplinary work approach in order to build a conceptual and methodological framework to explore three interrelated questions:

• (i) What would be the surface area of legumes needed to satisfy the needs in plant proteins for human and animal food in Occitanie by 2050 in a context of climate change, growing populations, and diet transitions?
• (ii) What scenarios for integrating legumes into cropping systems would improve the climatic and food resilience of the Occitanie territory?
• (iii) What levers and obstacles would these cropping systems face, particularly in terms of targeted markets?

In order to move forward with a modelling approach at the regional level, the project has two specific goals: 1) to develop a model simulating the supply and demand of grain legumes in Occitanie based on the expertise of a variety of stakeholders in the region, and to assess the associated agronomic and environmental performances through the modelling of cropping systems; 2) to explore how different grain legume development scenarios will affect these performances by 2050.

Two major advances are expected. This work will allow us to build a conceptual and methodological model applied to the Occitanie region, and to derive a framework that is sufficiently generic to be redeployed to other regions. It will also allow to propose legume development scenarios in Occitanie that contribute to both adaptation and mitigation objectives, while taking into account the constraints of the territory. Ultimately, these results will help support public and collective policies in making decisions about field crop rotation in the region.

INRAE units involved

• AGIR, Toulouse
• MISTEA, Montpellier