Cover crops sown in the inter-rows shape the weed communities in three vineyards across Italy

Abstract

The use of cover crops (CCs) is widely proposed as an alternative to traditional soil management in vineyards to exploit a wide range of ecosystem services. The presence of a CC in the inter-row space is known to control spontaneous vegetation in vineyards, primarily through the biomass of the sown crop, which competes with other spontaneous species for soil resources. However, knowledge about how CCs shape vineyard weed communities remains limited. Understanding the traits associated with plant communities in different inter-row managements allows to understand the best practices to mitigate the disservices caused by these communities (such as competitive species) while promoting biodiversity.

Three different CCs (Vicia faba L., Secale cereale L., and a mix of both) were sown in autumn 2023 and compared with a tilled control. Each treatments were applied in both the vineyard inter-rows in a completely randomized design, with plots of 10–12 vines each. This experimental design was replicated in three Italian regions: Friuli Venezia Giulia (north), Tuscany (center), and Apulia (south). The CCs were terminated between April and May. At termination, the weed community composition was assessed by measuring the dry biomass of each species in two quadrats of 0.25 m² per plot. Inter-row vegetation biodiversity was assessed again at the end of the growing season through visual cover estimation of each species within the quadrats. Each species was associated with various functional traits (e.g., including family, height, and root apparatus type) which were retrieved by functional trait databases such as LEDA.

The spring and autumn surveys revealed distinct effects of the soil management treatments on the weed plant communities. The communities established alongside the CCs in spring were directly influenced by competition with the cover crops, while those that developed in late summer were affected by both soil management and CC termination. The weed community composition varied largely by geographical location. Vineyards in the region of Apulia displayed different weed compositions compared to those in Tuscany and Friuli Venezia Giulia. CC soil management showed the ability to modify functional traits of the weed communities in different locations, although some effects were consistent across all locations. These results suggest the potential to shape weed community traits through CC practices across varying vineyard environments.