- Could you briefly describe CrosyeN?
Yann Nouvellon: CrosyeN is an acronym for Cropping System Experimental Network. It does just what its name implies: it uses cropping system experiments to design and assess agroecological systems that are adapted to climate objectives, energy transitions, and environmental transitions. In other words, the goal is come up with systems that consume minimal amounts of fossil fuels while simultaneously meeting general societal expectations around agriculture, notably in regard to biodiversity, food security, economic security, human health, and environmental health.
CrosyeN began in April 2023 and will run for five years. It is coordinated by CIRAD in close collaboration with INRAE and IRD. The project is led by a multidisciplinary team of researchers, primarily experts in agronomy, agroecology, agroforestry, biogeochemistry, and soil science.
We also have several international collaborators at foreign universities because, in addition to its four experimental sites in France, the project has four experimental sites abroad, in Zimbabwe, Cambodia, and Vietnam. In France, we have a network of non-academic partners that includes representatives from various chambers of agriculture and the agricultural industry. All these experimental sites are already up and running. CrosyeN is helping to build networks and standardise data collection, with a view to creating a scientific community focused on designing new cropping systems.
More specifically, we want to construct a network of experimental cropping systems, equip them with measurement devices, collect data, and compare their results with those obtained from conventional production systems. Thanks to this approach, we will be able to test different combinations of agricultural strategies, such as crop diversification across space and time during successive rotations, maximising soil cover, reducing tillage, and planting legumes to reduce inputs.
- What is CrosyeN’s international significance?
Yann Nouvellon: Climate change means we need to limit fossil fuel use and plant appropriate crops. CrosyeN is therefore fully in alignment with the Paris Agreement and the European Union's goal of carbon neutrality by 2050. Not only must we drastically reduce fossil fuel usage, but we must also work with the agricultural industry to bump up levels of carbon sequestration and storage to deal with residual emissions. These goals can only be reached if the industry makes major changes to its farming practices and cropping systems. Indeed, modern agriculture is currently responsible for 11% of global greenhouse gas emissions, largely because of mechanisation and the use of fertilisers, whose production requires massive quantities of fossil fuels.
Additionally, its input-intensive practices are causing groundwater pollution and biodiversity declines.
- CrosyeN is centred on "experimental cropping systems". Can you explain what these are?
Yann Nouvellon: A cropping system can be defined as a set of procedures employed to produce plants, whether for food or other uses. It also consists of a particular temporal sequence of crops and the technical itineraries applied to each crop. By experimenting with cropping systems, we can compare conventional systems with innovative systems, such as pilot systems, and explore the results of different combinations of agricultural strategies, such as using legumes, modifying rotations, or maximising soil cover to limit nitrate losses, for example.
Our experiments have several stages. First, we have to define our objectives, then design and implement the pilot cropping systems or strategies that we want to use in our comparisons. Once running, these systems yield data on productivity, greenhouse gas emissions, levels of labour, soil biodiversity, and soil carbon storage, among other variables. We can then compare these systems using all our target criteria and, finally, transfer the results to stakeholders in the agricultural industry.
- How and why do you evaluate the multidimensional performance of cropping systems?
Lionel Alletto: When evaluating cropping systems, we are studying variables that are inherently multidimensional. Conducting a multicriteria assessment allows us to holistically examine sustainability by considering how variables potentially affect each other. We have three categories of sustainability criteria: economic, social, and environmental. Within each category, we will have a set of indicators that can shed light on specific issues. The aim is to attain a more global perspective. Because many methods and indicators are already available, one of CrosyeN’s goals is to build a network of contrasting experimental cropping systems so we can select, organise, and group indicators for a shared evaluation method.
- Will this work require creating experimental infrastructure?
Yann Nouvellon: Our infrastructure goals are to identify and provide the material resources and human resources that are required by long-term experiments, which are often challenging to maintain over time. Indeed, CrosyeN is interested in long-term issues. Our objective was to create an infrastructure that would establish a network of sites, guide and support their work, and address some particular concerns. More specifically, the question is how to assess experimental system performance and sustainability overall within each region. Such is the basis for our project’s coordination efforts and objectives: to bring these experimental systems together within a network and provide financial support so that they can achieve medium-term, if not long-term, visibility. It is necessary to renew or upgrade certain equipment at certain sites to slightly improve monitoring breadth and quality. Then, all the network members can interact and furnish the same set of target data.
- How will you transfer your findings to the private sector?
Lionel Alletto: Although we will carry out a comprehensive assessment at the end of the project, knowledge transfer to the agricultural industry will be ongoing. The aim is for the experimental cropping systems to serve as a conduit for interactions and discussion. Local professionals are regularly invited to participate in meetings and in exchanges among stakeholders involved in agricultural development. The experimental sites are also points of information transfer, a process that will continue throughout their lifetimes. It is the entire life cycle of the experimental systems that counts, not just the final evaluations. Agricultural stakeholders will be involved the whole time, and it is important to consider their feedback.
Yann Nouvellon: CrosyeN will technically run for five years, but it has put a whole framework in place and has fostered contacts with all the visits to the sites. Thus, we are creating an experimental ecosystem that is destined to last more than five years. We really hope that our network will outlast our project.
- What makes CrosyeN unique?
Yann Nouvellon: Exchanges among sites are already occurring, although not on the scale we have planned. Also, things are slightly more informal and are organised around specific topics. They do not deal with large sets of criteria.
Lionel Alletto: In general, we carry out assessments after the fact. However, CrosyeN will strive to be more proactive, to plan a bit further ahead, using the exchanges and networking to generate a shared database. This approach is quite new compared to the usual mode of operation.
- What are CrosyeN’s main work tasks?
Yann Nouvellon: The first step is to set up the experiments. Then, we need to design the standardised measurement protocols for all the variables and establish a data management plan. Next, we will need to monitor the experiments, including the data acquisition and archiving processes. Then, the data will need to be made available to researchers involved in the project as well as to others.
The second step will be to define the criteria and methodology to be used in the multicriteria analyses.
Finally, once these analyses have been completed, the results will be published and shared with policymakers. While CrosyeN is running, we will be engaged in complementary activities—training programmes, site visits, and meetings with industry professionals.
- What are the main expected results of your work?
Yann Nouvellon: In addition to generating basic knowledge about how these ecosystems function, we want to make the resulting data available to the entire scientific community. We will also be collaborating with academic researchers, so the project will be training students. Additionally, we will be working with professionals from the agricultural industry. CrosyeN will answer practical and theoretical questions about how our experimental cropping systems function.
Lionel Alletto: To expand on Yann's comment about interacting with the agricultural world, certain sites organise day-long visits dedicated to certain practices, such as how to destroy vegetation cover mechanically instead of with chemicals. While this practice has not yet been widely adopted by farmers, it represents an important first step towards crop diversification and soil carbon storage. Numerous visits of this type have taken place at our sites and have helped disseminate the technical know-how of our site teams. Over time, they will acquire a wide range of skills.
Yann Nouvellon: The experimental cropping systems have a well-established presence in their local agricultural ecosystems. Industry professionals have been invited to help co-design the systems, a process that thus involves multiple partners.
