Context

If agriculture has experienced major gains in productivity (homogenization and intensive use of input), this model is jeopardized by the awareness of rapid global change, increased environmental stochasticity and the need for greater sustainability of agriculture. A new paradigm is emerging, in which agriculture is more relying on ecological functions within agroecosystems. Crop genetic diversity, like varietal mixtures, should play an essential role in this context, as a key element to reduce the use of chemical inputs. The introduction of intra-specific diversity using cultivar mixture might be one solution, as it could promote various ecosystem services* essential for yield stability, adaptation to climate change, and pest and disease resistance.

* Ecosystem services: benefits that men receive from ecosystems. Some examples: operating tradable goods (food, building materials...), air quality maintenance, water purification, creation of jobs...

Wheatamix project objectives

Assessing agroecologic and socioeconomic impacts of wheat blends, and evaluating the potential of ecosystem resilience in a context of global change.

Wheatamix aims at four major goals:

• Determine the diversity of wheat varietal traits and their plasticity in blend, and whether the combination of traits allows a better use of resources

• On the basis of varietal traits of interest, choose the best associations and assess their resilience and stability

• Assess the ecosystem services provided by varietal mixtures under different environmental conditions

• Assess the blends impact on wheat supply chain, and the feasibility of their adoption, from farmers’ community to consumers

Project area The project includes a farm network extended in 6 departments of the Paris basin: Cher, Eure, Indre, Loir-et-Cher, Loiret and Seine-et-Marne. There are also experiments on different sites of INRA: Versailles, Le Moulon, Rennes, Clermont-Ferrand and Toulouse.

Structure of the project

The project is structured in four workpackages (WP 1 to 4), and one coordination mission (WP0).

The complementarity between the different WP allow to study variety mixtures at different spatial scales, from the plot to the wheat supply chain.

Project planning

The project is divided in 4 missions in parallel :

WP1 : measuring phenotypic and genetic traits on 60 wheat varieties. In parallel, development of an ecophysiological model at the plant scale (it will be continued the two next years)

WP2 : on the experiment site of Versailles, assessing ecocystem services (aphids predation rate, nitrogen activity and microbial communities, etc…) on 2, 4, an 8-way mixtures and on the associated monocultures.
On the multisite experiment, measuring the yield performances (number of plants, number of spikes/plant, number of grains/ spikes, thousand kernel weight)

WP3 : ideotyping wheat mixtures (with scientists, advisors from Chambres d’Agriculture and farmers) and interviews of stakeholders about impacts of mixtures on the value chain of wheat sector

WP0 : coordination and organization of an annual meeting in December 2014, to discuss about first results and next works

Estimation of the organization of the WPs missions on the 4 years :