Case study 14: France: Diversification of arable crops rotations, specialised on winter crops, under oceanic situations

Cluster 3: Crop diversification in systems from Western Europe

The case study will contribute to the development of low input systems by improving weed management and soil fertility, maintaining economic margins and improving robustness over oceanic situations. Introduction of legumes in the crop sequence and intercropping seems to be an efficient in reducing nitrogen use, energy consumption and greenhouse gas emission at the same time.

What are the main problems underlying the emergence of the case study?
The emergence of multi-performing farms requires a shift toward new production systems (including new crop sequences), based on ecological intensification, adapting to local conditions, and manageable by farmers.  
The global objective of the case study is to produce references, know-how, and tools, to promote innovations in arable crop production by mobilizing farmers and stakeholders. Over oceanic situations, in shallow, clay-limestone soils where cropping systems are quite simple (winter oilseed rape, winter wheat, and winter barley with reduced tillage), the case study must contribute to the development of low -input systems by improving weed management and soil fertility, maintaining economic margins, and improving robustness.

How is the problem addressed and which actors are involved?
The three French technical institutes of arable crops Arvalis-Institut du végétal, ITB, and Terres Inovia launched in 2014 a national project about co-design, ex-ante evaluation, and experimentation of multi-service farming systems matching with regional challenges. 
The Case Study, “Diversification of arable crop rotations, specialised in winter crops under oceanic situations”, is one of five locations, representing main arable crop production systems in France.
In order to build the case study, the methodology of de novo co-design of cropping systems was applied to reconcile global issues and local constraints. Working groups have been set up with farmers, local advisors, researchers, crop specialists, and grain collectors to keep a view on new production opportunities.
Five steps were followed to design innovative cropping systems: i) identifying local issues based on a prospective study and defining a local set of goals and constraints, ii) defining the most representative cropping system in the region, and its limitations, based on regional statistics and local expertise, iii) identifying candidate crops and suitable agronomic strategies, based on general knowledge and local expertise, iv) designing innovative cropping systems, and v) making an ex-ante assessment of each system.
This first work has led to the implementation of “cropping systems experiments” (WP3) and factorial trials.
In parallel, Terres Inovia has led a group of innovative farmers in that region since 2005, with the aim to accompany farmers in the step -by -step design of innovative cropping systems. Some of these farmers have been associated in the design workshops described above, and links are developed between the experimental platform and this group to favor the mutual exchange of experiences and knowledge. 

Solution investigated
The „Library of Ideas" was compiled during the meetings of the working groups. Each practice was described with its agronomic function and expected benefits for the systems. Practices like the introduction of legume or permanent cover crops and reduced tillage were mentioned. Double cropping or crops in association were also proposed to improve soil productivity. Moreover, the use of robots, biocontrol solutions or stress tolerant varieties were considered to reduce input dependency. Five systems were co-designed from this library of ideas.
According to the ex-ante assessment, in this case study, legume crops were introduced as cash crops (lentil and pea), intercrops, and cover crops in the crop sequence and seems to reduce nitrogen use, energy consumption, and greenhouse gas emissions simultaneously. A succession of two spring crops (maize and sunflower) can be introduced for breaking the weed cycle. Minimum tillage and permanent cover (through cover crops) should be applied to favor soil fertility.

Expected outcome
The case study has social, economic, and technical expectations towards DiverIMPACTS. The project will answer questions on how to scale out innovative cropping systems to farmers, involve collectors, and promote emerging and new supply chains. The commercialization and competitiveness of new crops should be explored besides specific technical advice on the production of rainfed maize, pest control in intensified legume presence (Aphanomyces and Sclerotinia), and the efficient management of complex cropping systems.

Relevance to the DiverIMPACTS goals
The relevance of this case study for the DiverIMPACTS goals is due to the consideration of a situation with a technical impasse, in terms of weed and insect damage control, in which crop diversification can be a relevant solution. This solution was proposed following a collaboration between farmers, advisors, and stakeholders.
 

Contact

  • Gilles Sauzet, Terres Inovia, Case study leader
  • Stéphane Cadoux, Terres Inovia, Case study leader