Case study 5: France: Breaking irrigated maize monoculture

Cluster 1: Service crops

Negative impact of maize mono-cropping and problems in terms of weed management, soil erosion,  soil quality and pest pressure pushed farmers from the Hautes Pyrenees and Pyrénées-Atlantique to look for agronomic innovations, as crop diversification, to solve the problem with the actors upstream and downstream the value chain.

What are the main problems underlying the emergence of the case study?
Since the beginning of the 1990s, water agencies have highlighted the negative impact of maize mono-cropping on water resources both in quantitative and qualitative terms. In addition, farmers are facing agronomic problems in terms of weed management, soil erosion, and soil quality and pest pressure (e.g., wireworms). They took some actions to limit nutrient and water losses but, in a period of high maize prizes, these were not adopted by the farmers.

How is the problem addressed and which actors are involved?
Since the price of maize grains for feed started to fluctuate, farmers began looking for information to reduce production costs while solving their agronomic problems. Some of them are involved in the Ecophyto dynamic. This dynamic has mobilized around 3000 farms in France, with around 220 farms in the southwestern part of the country. Twenty farmers from the Hautes Pyrenees (maize grains mainly exported in Spain) and Pyrénées-Atlantique (maize grains for local pigs or poultry production) are looking for agronomic innovations to solve these problems. This dynamic has to be supported.

Solution investigated
Crop diversification is a potential solution, as underlined by some trials that aim to set up rapeseed production in the rotation. Some farmers would like to introduce spring crops in the rotation; soybean, for example. The introduction of other cereal crops within the rotation may lead to the increased use of pesticides, which calls for solutions. There is a need to support the evolution/organization of the upstream and downstream parts, i.e., cooperatives, of the chain. The use of service crops involving, for example, cruciferous species (sown sole or intercropped with legumes), is also a promising alternative to control wireworms but requires further adoption.

Expected outcome
Face socio-economic lock-ins involving up- and downstream actors in the value chain. Get familiar with the introduction of alternative spring crops such as soybeans on regional and local scales in order to share methods, results and promote discussions between farmers and engineers. Reduce the dependence on pesticide input through adopted management strategies.

Relevance to the DiverIMPACTS goals?
One objective of the DiverIMPACTS project and the clusters in Hautes-Pyrénées and Pyrénées Atlantique is to set up some working groups with the regional cooperatives in order to clearly identify the lock-ins that are limiting crop diversification.


  • Olivier Micos, APCA Occitany, case study leader
  • Lionel Alleto, APCA Occitany, case study leader