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RESEARCH PRODUCT

Performances of pesticide-free agroecological cropping systems: the CA-SYS platform

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Meeting the challenges of current agriculture requires the development of innovativecropping systems with high environmental, economic and social performances. Agroecologyseeks to optimize the services provided by cultivated and wild biodiversity to reduce thereliance on external inputs while maintaining/increasing cropping system sustainability.Maximizing the delivery of ecosystem services from biodiversity requires an in-depth redesignof production systems considering in-field management as well as ecological infrastructuressurrounding the fields. An agroecological system experiment aims to design and assesscropping systems, the spatio-temporal arrangements of these cropping systems andecological infrastructures at the farm level (Petit et al., 2021).Located on the INRAE Domaine d’Epoisses experimental farm (Bretenière, France), the CA-SYSplatform is a collaborative research platform experimenting agroecology. Since 2018, anagroecological system experiment has been implemented on 125ha, and tests pesticide-freeagroecological systems comprising four cropping systems and a high density of ecologicalinfrastructures (Petit et al., 2021). The pesticide-free constraint is as well an objective toenhance the beneficial organisms involved in the biological regulation of pests and improvethe environmental performance of the systems. The four cropping systems represent twomain agricultural strategies that may foster biotic interactions: 1) two tillage-based systems(occasional ploughing, false seedbed, mechanical weeding); 2) two conservationtillage/agriculture systems (i.e. rotational/permanent no-till). These two options requiremobilizing crop and cover crop diversity in time (at the scale of the crop succession) and space(e.g. mixture of crop species and/or varieties, companion crop). Legume crops play animportant role in contributing to pest management (diversification of crop species and sowingdates) and in reducing N fertilizer. Other agroecological practices are combined in thecropping systems to have robust and competitive crops (e.g. choice of resistant cultivar,delayed sowing date, increased sowing density). The implementation of agroecologicalprinciples started in summer 2018 with the objective to reach similar profitability andproductivity than in neighbouring conventional farmers at a 10-year horizon. Data arecollected on a yearly basis to assess crop performances through agronomic diagnosis, systemsperformances through a multi-criteria assessment, and the ecological transition through atemporal analysis of ecological indicators.After three years of experiment, the performances of the four cropping systems were assessedwith the MASC 2.0 multi-criteria assessment method (Craheix et al., 2012). The cropping114systems have intermediate to high environmental performances (high air and water quality,biodiversity conservation, intermediate energy consumption, intermediate to low energeticefficiency) and intermediate social performances (high farmer’s working conditions but lowsupply in raw material). However, the cropping systems have low economic performances(low productivity and profitability). Yield losses due to difficulties to manage pest pressures(e.g. diseases on protein crops, insects on oilseed rape; slug and vole damages and weeds inno-till systems) partly explain the low economic profitability, despite the low input costs. Lowprofitability is also partly due to several crops, used to diversify crop rotations, but with lowproductivity and poorly valued in the current sectors.The difficulties in the management of some of these innovative agroecological croppingsystems and their unsatisfactory performances have prompted some adjustment of farmingpractices. Further multicriteria assessment, i.e. at the end of the crop succession, will benecessary to analyse the impact of these adjustments. In addition, we expect in the comingyears that the ecological infrastructures implemented in 2018 will increase beneficialorganisms to improve pest management in the pesticide-free context of the platform.Methodological developments are needed to assess the whole agroecological system,including the ecological infrastructures.