The more plant species and plant cover you have on your entire vineyard floor, the higher soil organic carbon and water infiltration rates you will see as a result, preliminary findings of a new study suggest.

The research project compared 25 vineyard sites in McLaren Vale and the Barossa which have been using different vineyard floor management practices for at least the past three seasons. 

Soil measurements and plant diversity were then evaluated seasonally at each vineyard during one growing season. 

“This approach aimed to uncover any trends associated with how particular practices across a viticultural landscape, such as herbicide-use, cultivation, grazing, and cover crops, influenced dynamics related to soil health and biodiversity,” said Merek Kesser, a viticultural PhD candidate at the University of Adelaide, and a Wine Australia PhD scholarship recipient.

Merek said the Barossa and McLaren Vale regions provided excellent opportunities to carry out this research as they are both premium wine-producing areas with a high density of land used by vineyards. 

“It is unusual to use entire vineyard sites as replicates in a scientific study, yet we did just this as we thought it was important to capture what is happening on a larger scale in the sector. Studying at the landscape level allowed for the assessment of how management practices can have different outcomes depending on the many site-driven factors that come into effect, including for example, soil type.”

While results are still in the preliminary stage, Merek said it was apparent that practices which increased the number of plant species and the duration of complete plant coverage (in both the mid- and under-vine areas) resulted in soils with faster water infiltration rates and higher contents of organic carbon.

“In Australian conditions where access to ample irrigation water is a major concern, these are very insightful findings, which if taken into consideration could have a great influence on the environmental health of viticultural landscapes.”

Merek said integrating a living mulch of diverse or native plant species into the under-vine area would ultimately benefit the functionality of the soil and improve long-term vineyard resilience. 

She said the research could help growers in selecting floor management strategies going forward, “which can maximise the long-term resilience and sustainability of their vineyard based on their specific production goals and site constraints.”  

“With increasing pressures from external factors such as changing climate, more frequent droughts, and shortages of farm inputs including fertilisers, we are hopeful that simple vineyard floor management strategies such as keeping complete living plant coverage year-round on vineyard floors could provide holistic agroecosystem benefits.”

Source: Wine Australia