The French National Institute for Agricultural Research (INRA) has established an ambitious experimental infrastructure (the CA-SYS platform) in autumn 2018 after 5 years of co-design with farmers, crop advisors and researchers. CA-SYS covers an area of 125ha divided into 42 fields. The originality of CA-SYS is that it is explicitly conceived for the design and evaluation of biodiversity-based and pesticide-free agroecological systems across agriculturally realistic scales. An agroecological system will comprise a matrix of fields of one (or a few) cropping systems over a number of years interacting with adjacent semi-natural habitats (hedges, grass margin strips, flower strips). This spatio-temporal arrangement of fields and semi-natural habitats is considered as a coherent strategy, implemented to meet specific goals. CA-SYS has ambitious objectives, including a high multi-performance of systems (profitability and productivity identical to neighbouring farmers over a 10 year-horizon, low environmental impacts, etc.), by maximising the use of biological processes (biological control of pests, improving nitrogen cycling, etc.) and reducing the use of inputs (nitrogen, water, pesticides). Among the four pesticide-free cropping systems tested, CA-SYS tests 2 cropping systems implementing conservation tillage and agriculture principles: a permanent no-till cover crop-based system (SD1) and a rotation no-till system (SD2). They are both 6-year crop rotation including 7 cash crops (buckwheat is cropped as secondary crop in between winter barley and winter wheat). Soil remains covered as much as possible through a high temporal and spatial diversity of cropped-plants. Oilseed rape is cropped with spring fababean and Berseem clover as companion crops. Fallow periods in between winter wheat/soyabean is covered by two successive cover crops (i.e. summer and automn sown). Cereals are intercropped with legumes (wheat/fababean, spring barley/spring pea) to enhance crop complementarity. A mix of 4 cultivars are sown for oilseed rape and winter wheat to manage pests.