Under-vine and between the rows: investigating sustainable floor management in vineyards

Abstract

Investigating vineyard floor management is essential as these practices directly impact soil health, vine growth, and grape quality. Traditional methods, like tilling or herbicides, control weeds but can harm soil structure and biodiversity, while alternatives like cover cropping and mulching may offer environmental benefits and introduce trade-offs in water and nutrient availability.

In 2019/2020 a vineyard floor management trial was established at the University of Adelaide, Waite Campus, Australia. Mid-row treatments were a mown spontaneous cover crop and a rolled cover crop of oats and peas. In the under-vine area, treatments included herbicide, cultivation and mowing. All treatments were replicated four times. Measurements of vine performance, yield, maturity, soil health, and plant species diversity (between and during the seasons) were recorded during 2021-2024.

Rolling the mid-row vegetation increased pruning weight without any effect on yield. The only significant differences in maturity data were a lower berry weight when the under-vine area was cultivated versus herbicide treated, and the pH being highest when the under-vine was herbicide treated, followed by cultivated then slashed. Phenolics and anthocyanins were higher when the under-vine was cultivated versus herbicide treatment, regardless of mid-row treatment. Differences in percentage ground cover were significant when looking at the various under-vine treatments, with slashing providing the greatest coverage, followed by cultivation then herbicide treatment. Whilst the differences between groups were not large, herbicide in the under-vine area decreased berry weight, total phenolics and anthocyanins, biodiversity, percentage ground cover and biomass. Greater plant diversity and ground cover observed in mown treatments corresponded to a significant improvement in soil water infiltration rates and increased soil organic carbon levels. These findings suggest that diverse plant cover, particularly under-vine, contributes to healthier soil, potentially increasing vineyard resilience amid environmental challenges like drought and limited water access. Understanding the impacts of under-vine and mid-row treatments can help vineyard managers balance these factors, promoting more sustainable and productive viticulture practices.