Combining grapevine yield, soil quality and service crops: results from a three-year on-farm experimentation in the Mediterranean region

International audience

English. Enhancing soil organic matter is key to sustainable viticulture. This study evaluates strategies to improve soil quality and viticultural performance in the Mediterranean. Winegrowers, acknowledging the impact of soil health on yield and resilience, are adapting to evolving policies like the anticipated glyphosate ban by turning to alternatives like cover crops for effective weed management (Cataldo et al., 2021; Jacquet et al., 2021). Cover cropping is increasingly adopted for its benefits in reducing herbicides, boosting soil quality, and water resource management (Garcia et al., 2018). Organic amendments are also used to enrich soil and recycle nutrients (Mondini et al., 2018). Challenges in cover cropping and organic amendment implementation prompt research into resource management and soil property changes (Crystal-Ornelas et al., 2021). At the farm level, the diversity of viticultural practices reveal continuous uncertainties among winegrowers about the effectiveness of ecosystem services and the long-term viability of cover crop management strategies. The Occitanie-funded RESAMOVITI project, involving the ABSys research unit, the French Institute for Vine and Wine (IFV), agri-suppliers (Frayssinnet Club Authentis), and winegrowers, focuses on sustainable soil management, assessing cover crop and organic amendment interaction to improve soil health and yield in diverse Mediterranean conditions.Materials and Methods:Seven vineyards across the Mediterranean region participated in the project, with winegrowers actively involved. Soil characteristics were analyzed in 2019 and 2023, while grapevine and cover crop indicators were monitored during the years 2020-2022. Four modalities combining or not amendment and cover crop in comparison with a bare soil control were tested in the inter-rows of each experimental field.ResultsResults indicated that cover crop development was strongly influenced by sowing (Figure 1) and termination dates, initial rainfall and cumulative degree days. Cover crop biomass varied across plots and years, with no discernible impact of organic amendments (from less than 1 Mg ha-1 to more than 7). Potential carbon and nitrogen returns from cover crops depended on their development and management, including modulation of the C/N ratio based on the destruction date. Moreover, the presence of cover crops notably enriched soil labile and stable organic carbon content even after three years only. Results about nitrogen balance varied a lot from one field to another, depending on the initial soil content; at the network level, the study demonstrates that cover crops in Mediterranean conditions did not affect vine nitrogen status at flowering or veraison compared to a tilled control. A decrease in yields and vigor due to cover crops was observed in some fields. Nevertheless, this competition appears to decrease in the presence of amendments. Additionally, other factors might influence resource competition between vines and cover crops, thereby affecting yield and vigor. For example, the method of destruction notably influences soil nitrogen availability and could therefore impact vine performance (Garcia et al., 2024).Conclusion:The RESAMOVITI project provides valuable insights into cover crop dynamics and their impact on Mediterranean soil-vineyard systems highlighting that covercropping improves soil quality, and is compatible with grapevine yield if well managed. . These findings inform optimized management strategies and support sustainable viticulture practices.Cataldo, E., Fucile, M., Mattii, G. B. (2021). A review: Soil management, sustainable strategies and approaches to improve the quality of modern viticulture. Agronomy, 11(11), 2359.Crystal-Ornelas, R., Thapa, R., Tully, K. L. (2021). Soil organic carbon is affected by organic amendments, conservation tillage, and cover cropping in organic farming systems: A meta-analysis. Agriculture, Ecosystems & Environment, 312, 107356.Garcia, L., Celette, F., Gary, C., Ripoche, A., Valdés-Gómez, H., Metay, A. (2018). Management of service crops for the provision of ecosystem services in vineyards: A review. Agriculture, Ecosystems & Environment, 251, 158-170.Garcia L., Krafft G., Enard C., Bouisson Y., Metay A., (2024), Adapting service crop termination strategy in viticulture to increase soil ecosystem functions and limit competition with grapevine. European Journal of Agronomy (in press).Mondini, C., Fornasier, F., Sinicco, T., Sivilotti, P., Gaiotti, F., Mosetti, D. (2018). Organic amendment effectively recovers soil functionality in degraded vineyards. European Journal of Agronomy, 101, 210-221.Jacquet, F., Delame, N., Vita, J. L., Huyghe, C., Reboud, X. (2021). The micro-economic impacts of a ban on glyphosate and its replacement with mechanical weeding in French vineyards. Crop Protection, 150, 105778.