Project

Biodiversity-based agriculture refers to a strong ecological modernization of agriculture based on an ecocentric approach (Hill 1998) relying on high biological diversification of farming systems (Kremen et al. 2012) and intensification of ecological interactions between biophysical system components promoting fertility, productivity and resilience (e.g. Duru et al. 2015). Despite the role of biodiversity in ES delivery remains not fully understood, high spatiotemporal biodiversity from the field to the landscape level has been shown to provide resilience of the systems in changing environments (Quijas et al. 2010).

Although the landscape level must not be neglected, crop diversification at the farm and CS, often mentioned as ‘agroecological practices’, strongly contributes to the valorisation of ecological processes and ESs in considering them as fundamental elements for crop production (Wezel et al. 2014). In CCS, previous and cumulative effects of succeeding crops within the rotation affect the quality of soil organic matter, structural stability, nutrient cycling, weeds and pests control (e.g. Duru et al. 2015). Designing diversified rotation crops with plants mixtures well adapted to the local context would result in functional complementarity, facilitation, and synergisms between species and genotypes in time and space. Together with the implementation of low‐input agronomic practices, crop diversification is highlighted as a key issue for future sustainable development of agroecosystems valorising natural and cultivated biodiversity for agricultural purposes (Kremen and Miles 2012, Stagnari et al. 2017, Duru et al. 2015).

Thanks to SNF and N rhizodeposition (Fustec et al. 2010), the introduction of legumes in Mediterranean CCSs 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 ESs provided by biodiversity-based CSs: 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 CCSs. 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 ESs 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.

Most farmers have to face lock‐ins regarding crop diversification: lack of references (new crops, new management practices), of adapted varieties, of technical 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). To enhance the development and adoption of these approaches 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 CCSs

evaluations and transfer scientific knowledge. Overall, for supporting the transition toward sustainable and resilient biodiversity-based CCSs matching with future challenge in the Mediterranean Basin.