THE 4C APPROACH AS A WAY TO UNDERSTAND SPECIES INTERACTIONS DETERMINING INTERCROPPING PRODUCTIVITY

Modern agriculture needs to develop transition pathways toward agroecological,resilient and sustainable farming systems.One key pathway for such agroecological intensification is the diversification of cropping systems using intercropping and notably cereal-grain legume mixtures.Such mixtures or intercrops have the potential to increase and stabilize yields and improve cereal grain protein concentration in comparison to sole crops.Species mixtures are complex and the 4C approach is both a pedagogical and scientific way to represent the combination of four joint effects of Competition,Complementarity,Cooperation,and Compensation as processes or effects occurring simultaneously and dynamically between species over the whole cropping cycle.Competition is when plants have fairly similar requirements for abiotic resources in space and time,the result of all processes that occur when one species has a greater ability to use limiting resources(e.g.,nutrients,water,space,light)than others.Complementarity is when plants grown together have different requirements for abiotic resources in space,time or form.Cooperation is when the modification of the environment by one species is beneficial to the other(s).Compensation is when the failure of one species is compensated by the other(s)because they differ in their sensitivity to abiotic stress.The 4C approach allows to assess the performance of arable intercropping versus classical sole cropping through understanding the use of abiotic resources.

TRANSLATING THE MULTI-ACTOR APPROACH TO RESEARCH INTO PRACTICE USING A WORKSHOP APPROACH FOCUSING ON SPECIES MIXTURES

The EIP-Agri multiactor approach was exemplified during a 3-day workshop with 63 project participants from the EU H2020 funded project“Redesigning European cropping systems based on species MIXtures”.The objective was to share firsthand experience of participatory research among researchers who were mostly not familiar with this approach.Workshop participants were divided into smaller multidisciplinary groups and given the opportunity to interact with representatives from eight actor positions in the value chain of the agrifood cooperative Terrena located in Western France.The four stages of the workshop were:(1)key actor interviews,(2)sharing proposed solutions for overcoming barriers,and(3)developing possible interdisciplinary concepts.Expressions of frustration were recorded serving both as a motivation for group members to become more aware of the scientific concerns and practices of their colleagues,as well as a recognition that some researchers have better skills integrating qualitative approaches than others.Nevertheless,the workshop format was an effective way to gain a common understanding of the pertinent issues that need to be addressed to meet overall multiactorapproach objectives.Working with the actor networks was identified and emphasized as a means to overcome existing barriers between academia and practice in order to coproduce a shared vision of the benefits of species mixture benefits.