Periodic Reporting for period 3 - ReMIX (Redesigning European cropping systems based on species MIXtures)
Reporting period: 2020-05-01 to 2021-04-30
ReMIX aimed at analysing and optimizing the functioning of species mixtures, also called intercrops, in order to help design sustainable and diversified cropping systems for both conventional and organic agriculture. The studied species mixtures were mainly cereals and grain legumes. Eleven multi-actor platforms (MAPs) were set up in ten countries in order to demonstrate potential performances and interests of species mixtures. MAPs were a rich picture of promising species mixtures embedded in local negotiations and adjustments by relevant actors securing developing effective solutions fitted to the social and economic context in which farmers operate.
Several knowledge syntheses, new experimental and modelling studies have been carried out to determine how plant traits (e.g. root architecture and canopy morphology), cropping practices (e.g. plant density), and environment (availability of N, P and water, light quality) influence the performances of species mixtures as compared to sole crops for the capture of abiotic resources and the control of animal pests, diseases and weeds. Novel ideas and specific concepts were developed in order to support breeding for intercropping. As much as possible, we aimed at converting scientific results into practical tools and synthetic information disseminated not only to farmers, advisors, and other farming sector stakeholders, but also to policy makers.
Several knowledge syntheses, new experimental and modelling studies have been carried out to determine how plant traits (e.g. root architecture and canopy morphology), cropping practices (e.g. plant density), and environment (availability of N, P and water, light quality) influence the performances of species mixtures as compared to sole crops for the capture of abiotic resources and the control of animal pests, diseases and weeds. Novel ideas and specific concepts were developed in order to support breeding for intercropping. As much as possible, we aimed at converting scientific results into practical tools and synthetic information disseminated not only to farmers, advisors, and other farming sector stakeholders, but also to policy makers.
Local MAPs activities highlighted that the socio-economic context is a major driver for the type of species mixture grown, in contrast to the information generally found in scientific literature that rather focuses on the mechanistic understanding of interspecific interactions.
The ‘four C’ approach (Competition, Complementarity, Cooperation and Compensation) was used to analyse the final outcome of plant-plant and plant-environment underlying ecological interaction mechanisms. The differences in plant traits and partial separation of the time period during which two or more species are cultivated together are the main drivers for the niche differentiation and/or facilitation that contribute to yield gains or increased resource use efficiency in intercrops.
There is still a lack of information on mechanisms at work in species mixtures to reduce weeds, animal pests and diseases, and hence contribute to the reduction of pesticide needs. Indeed contrasted results were obtained in field experiments about effects of intra- and interspecific mixtures on biotic interactions due to pests and beneficial organisms.
New ideas on breeding for intercropping were developed: the theory of hybrid breeding in maize based on the "general mixing ability" (GMA) and the "evolutionary plant breeding" (EPB) methods. Key-traits and defined ideotypes were identified for good performance in species mixtures, developed assessment tools for species mixture performances, screened existing varieties to estimate their mixing ability, and estimated and compared the genetic gains of new breeding schemes that will include key-traits, GMA and EPB approaches.
Modeling was used as the key tool for representing the functioning of species mixtures. Different types of models were developped: (1) functional-structural plant models, (2) process-based classical crop models (STICS, Florys) adapted for intercropping, (3) empirical models directly using data from experiments, and (4) expert-based qualitative models. Simulations illustrated the potential of species mixtures to be better adapted to variable water availability than sole crops, and the role of plant trait combinations conferring high yields, high resource use efficiency, good levels of pest control, and high productivity and resilience under higher weather variability caused by climate change.
Practical information was also produced on intercropping by assembling information from across ReMIX results and many other past and present EU and national projects into a tool box available to all (www.agrodiversity.eu). Specific guidance on settings for combined harvesters for intercropping have been provided, thus solving an important technical problem. Prototypes of decision support tools and teaching material, such as Interplay serious Game and Ecosystemix for ecosystems services assessment, were designed and validated with farmers and advisors.
Activities of dissemination were achieved to reach a wide range of publics: i) farmers, advisors, stakeholders and end-users through the organization of project events such as workshops and trainings in MAPs and 29 practices abstracts, ii) scientists and policy-makers with the organization of two final conferences in collaboration with the Diversify twin project, iii) students with a one-week virtual training school on intercropping, iv) general public and citizens with the use of social media (Twitter, Facebook groups), website, and newsletters, and a “YouTube channel” to broadcast project videos.
The ‘four C’ approach (Competition, Complementarity, Cooperation and Compensation) was used to analyse the final outcome of plant-plant and plant-environment underlying ecological interaction mechanisms. The differences in plant traits and partial separation of the time period during which two or more species are cultivated together are the main drivers for the niche differentiation and/or facilitation that contribute to yield gains or increased resource use efficiency in intercrops.
There is still a lack of information on mechanisms at work in species mixtures to reduce weeds, animal pests and diseases, and hence contribute to the reduction of pesticide needs. Indeed contrasted results were obtained in field experiments about effects of intra- and interspecific mixtures on biotic interactions due to pests and beneficial organisms.
New ideas on breeding for intercropping were developed: the theory of hybrid breeding in maize based on the "general mixing ability" (GMA) and the "evolutionary plant breeding" (EPB) methods. Key-traits and defined ideotypes were identified for good performance in species mixtures, developed assessment tools for species mixture performances, screened existing varieties to estimate their mixing ability, and estimated and compared the genetic gains of new breeding schemes that will include key-traits, GMA and EPB approaches.
Modeling was used as the key tool for representing the functioning of species mixtures. Different types of models were developped: (1) functional-structural plant models, (2) process-based classical crop models (STICS, Florys) adapted for intercropping, (3) empirical models directly using data from experiments, and (4) expert-based qualitative models. Simulations illustrated the potential of species mixtures to be better adapted to variable water availability than sole crops, and the role of plant trait combinations conferring high yields, high resource use efficiency, good levels of pest control, and high productivity and resilience under higher weather variability caused by climate change.
Practical information was also produced on intercropping by assembling information from across ReMIX results and many other past and present EU and national projects into a tool box available to all (www.agrodiversity.eu). Specific guidance on settings for combined harvesters for intercropping have been provided, thus solving an important technical problem. Prototypes of decision support tools and teaching material, such as Interplay serious Game and Ecosystemix for ecosystems services assessment, were designed and validated with farmers and advisors.
Activities of dissemination were achieved to reach a wide range of publics: i) farmers, advisors, stakeholders and end-users through the organization of project events such as workshops and trainings in MAPs and 29 practices abstracts, ii) scientists and policy-makers with the organization of two final conferences in collaboration with the Diversify twin project, iii) students with a one-week virtual training school on intercropping, iv) general public and citizens with the use of social media (Twitter, Facebook groups), website, and newsletters, and a “YouTube channel” to broadcast project videos.
Species mixtures are of high importance for future farming systems to meet policy requirements and consumer concerns about the relationship between the food they eat and their health, as well as environmental and ecological impacts of cropping practices that were used to produce it. Using a multiactor approach, ReMIX have stimulated situated, and independent, diffuse innovation activities in Europe expected to develop further beyond the project timeframe. Close collaborations with actors outside the traditional scientific community, all along the relevant value chains have been heavily involved in generating species mixture concepts with local/regional relevance bringing in ideas, views and opinions. Such co-ownership is expected to take species mixture into further development. Having said that, frontrunner farmers and companies engaged in such transition in various farming sectors are embedded in a network of actors used to simplified sole crop cultivation and time will be needed for a broader adoption of species mixtures in European farming systems. Results from field experiment and meta-analyses confirmed that species mixtures generally contribute to improve abiotic resource capture and production in low inputs systems. In addition, they also usually lead to a better control of animal pests, diseases and weeds, in given production situations, under specific cropping practices, including genotype specific effects. For optimum support of beneficial insects, fine grained plant spatial arrangements are crucial as natural enemies depend on sugar food sources in the near vicinity. The synthesis of worldwide data confirmed the great potential of species mixtures to reduce pesticide use. We demonstrated that the design of intercrops in terms of component species, management and configuration needs to be adapted to local demands, aspirations and possibilities. This requires to take into account the diversity of European production situations, not only in term of pedo-climates and landscapes, but also in terms of socio-economic contexts and markets. There is no "one size fits all" intercropping solution that suits all purposes. Local adaptation is needed.
In order to develop intercropping in Europe, institutional and regulation changes are required with possible new innovation arenas introduced with more direct value chain actor interactions. This will enable the development of new products and processes to add value and improve the range of products available to consumers.
In order to develop intercropping in Europe, institutional and regulation changes are required with possible new innovation arenas introduced with more direct value chain actor interactions. This will enable the development of new products and processes to add value and improve the range of products available to consumers.