Workpackage 2

Objectives

Study blend impacts on agro ecosystem functioning and bundles of ecosystem services provided.

Members involved

Coordinator: Xavier LE ROUX

Partners: LEM, Agronomie, iEES Paris, BIOGER, CA-FDGEDA, CESCO, ECOSYS

Missions

• Analyzing interactions between cultivated intraspecific diversity and (i) keys ecosystem services (ii) keys functioning ecosystems aspects. It aims at better understand the role of varietal biodiversity in providing services (including inputs reduction)

Services considered: yield and grain quality (including inter-annual variability), maintenance of soil fertility, regulation of main foliar diseases (rusts and septoria leaf blotch), biological pest control, regulation of weeds, and maintenance of biodiversity.

• Studying the compatibility among services (including yield and grain quality) and characterizing links between traits associated to blends and bundles of ecosystem services (synergies, trade-offs…). It aims at evaluating valuable services in low input systems to feed the socio-economic analysis of blend use in wheat sectors

Link to the other WPs:

Workpackage 3: Assisting the blend design, basing on the bundle of ecosystem services provided and their interactions

Workpackage 4: Assisting the conception of new breeding schemes

Field experiments

• Main diversity experiment:

Analysis of ecosystem services on large plots, with contrasted varietal diversity (INRA Versailles, years 1 and 2)

16 varieties are chosen, selected by their contrasting traits (size, nitrogen use...) and representing the diversity cultivated in the Paris region (7 varieties). Plots of 80 m² are planted with the 16 varieties in monoculture and also mixtures of 2, 4 or 8 varieties in equal proportions. In parallel, the 16 varieties are repeated twice on 80 m² plots. The plots are carried out at low input with optimal yield objective of 70%: fertilization at heading/flowering time, no fungicides or pesticides, and herbicides on demand, according to the density of weeds.

• Multi-site experiment:

Comparison of technical and economic performances between four-ways mixtures and monocultures associated (years 2 to 4)

Analysis of ecosystem services on plots with contrasted varietal diversity in different environmental conditions (years 1 and 2). It is the same experiment as above, repeated in 4 INRA sites in France (Rennes, Clermont- Ferrand, Dijon and Toulouse) and on plots of 7m². Plots are observed under low and high inputs, defined according to the local yield objectives. NB: 28 plots are added in year 2, including two-ways mixtures with the most contrasted varieties observed at year 1 (results of WP1).

• Farm network of "Chambres d'Agriculture":

Comparison of technical and economic performances between four-ways mixtures and monocultures associated (years 2 to 4)