DIVIcia - Use and management of Vicia species for sustainability and resilience in biodiversity based farming systems

Intensive agricultural systems are often characterized by low crop diversity (specific and genetic) associated with a large use of chemical inputs. They are widely questioned for their negative impacts on soils and environment and their lack of resilience (Altieri et al. 2015). This brings about a downward spiral of soil fertility decline and food insecurity. In addition, the loss of traditional crop species and variety diversity contributes to the decline of provisoning, regulating, and cultural ecosystem services (Duru et al., 2015), as well as the damage caused to soil quality. Most farmers have to face lock-ins regarding crop diversification: lack of references (new crops, new management practices) of adapted varieties, of technnical solutions, of guidelines to combine species in time and space, uncertainty in economic performance and lack of adapted downstream value chains for crop diversification products (Magrini et al., 2016).

Thanks to symbiotic nitrogen fixation and nitrogen rhizodeposition (Fustec et al. 2010), the introduction of legumes in Mediterranean cereal cropping systems either in sole crop in rotations, or within complex crop communities is of major interest, as they provide proteins for food and feed, enhance nutrient efficiency of agroecosystems (Hinsinger et al. 2011), and beneficial biotic processes. As legumes are able to provide nutrients to other organisms, they boost multi-trophic interactions (Einsenhauer 2012) and play a multi-functional role, enhancing ecosystem services provided by biodiversity-based cropping systems: they improve N-C-P cycles coupling, limit erosion, help to cope with resource scarcity and sudden stresses, mitigate volatility of input costs, increase resilience. Inter- and mix-cropping with legumes are recognized to better use natural abiotic resources such as water and nitrogen than sole crops, mainly in low-input cropping systems (Malézieux et al. 2009, Gaba et al. 2015, Brooker et al. 2016, Bédoussac et al. 2015). They also help reduce weeds and soil-borne diseases and pests, and provide environmental benefits (Corre-Hellou et al. 2011, Ehrmann and Ritz 2014). The introduction of alleles conferring host plant resistance and abiotic stress adaptation and high yields potential would enhance crop improvement, sustainability and resilience of Mediterranean diversified cereal cropping systems. Access to local and adapted varieties is critical for resilient agroecosystems especially under current global change (Ficiciyan et al. 2018). Elite cultivars and landraces harbour useful genetic variation that needs to be more easily utilized in plant breeding (Dwivedi et al. 2016). Further mechanistic understanding, selection and breeding of drought-adapted crops are required to improve the productivity and economic benefits of such systems and their adoption by rural actors. Soil biodiversity contribution to ecosystem services is now widely recognized, impacting plant productivity, water and air quality (Doran and Zeiss 2000). Soil organisms respond sensitively to land management practices and climate, with good correlation with ecosystem functions including water storage, C N P and other nutrients cycling, protection from pollutions and pathogenic organisms. Comprehensible and unexpensive indicators of soil quality are necessary for farmers to evaluate agronomic practices and help the transition toward sustainability and resilience of the systems. To enhance the development and adoption of legume-based diversification in the Mediterranean Basin, better networking and engagement of the different actors is needed (Migliorini et al. 2018, FAO 2018). The participatory approach is now widely recognised as a basic operational principle for sustainable development. Also, DiVicia will actively collaborate with farmers and other stakeholders to collect tacit knowledge, perform participatory cereal cropping system evaluations and transfer scientific knowledge.

For supporting the transition toward sustainable and resilient biodiversity-based cereal cropping systems matching with future challenge in the Mediterranean Basin, DiVicia will: · Promote knowledge exchange between farmers, other stakeholders and researchers, and promote participatory activities, · Combine innovations in crop diversification practices with well characterized, interesting and diverse new local and drought-adapted Vicia spp. genotypes, · Use and adapt assessment tools and diagnoses to evaluate and predict the effect of the proposed practices on the sustainability of biodiversity-based Mediterranean cereal cropping systems, · Provide tools to (i) better manage and predict the effect of agronomic practices on the soil fertility (C and N cycles and organic matter quality), (ii) assess the sustainability of the system and (iii) predict the economic benefits of sustainable practices at the farm scale, as economic actors are also essential to achieve the transition (FAO 2018), · Develop excellence training programs for young scientists in order to pursue and promote this approach, as researchers also play an important role in the development of agroecological practices (FAO 2018).