To determine if vineyard inputs can be reduced by growing winter-active plants in the under-vine strip, as a method to conserve water and reduce the need for herbicide sprays and cultivation.
The under-vine region of the vineyard floor contains the greatest concentration of vine roots, so management of this zone directly impacts vine yield, quality and profitability. Despite the under-vine zones importance, it has received little research effort committed to improving vineyard profitability. It is estimated that between $7 – 12 million are spent annually in the purchase and application of herbicides for under-vine weed control in Australian vineyards. Glyphosate resistant ryegrass is requiring higher rates of more expensive herbicides for control. The conundrum is that the zone of soil with the greatest level of root activity and potential influence on quality is not being treated in line with best soil management practice because the wrong plants are growing there and need to be removed.
The research will concentrate on a number of issues relating to ‘softer’, sustainable management systems, improved soil management practices and reduced inputs with some associated environmental and WHS benefits. The proposal seeks to trial plantings of grasses and prostrate legume species in the under-vine strip in vineyards in eight regions in South Australia and one additional site in the Riverina, NSW. Desirable attributes of the plants to be used include early vigour, self-seeding, soft-seededness, embryo dormancy, early/mid/late season senescence, availability and cost, ease of seeding, allelopathic qualities and insect resistance.
Monitoring of sown plant characteristics vs. weed growth will be carried out to assess their suitability. This will include assessment of biomass, seed production and the timing of flowering and senescence. ‘Next Generation Sequencing (NGS)’ methods will be used to measure soil microbial populations and genes involved in soil nutrient cycles, as well as soil moisture and strength.
Small-scale trial wines will be made from one site (in Year 3) to assess and compare the wines produced through the under-vine treatments and/or assessment of the sensory properties of wines from the different regions, with conventional practices.
The project will provide growers with the tools to change their management of the under-vine region of the vineyard, away from synthetic herbicides towards a more sustainable, low-input non-chemical approach, which includes fewer herbicide applications, less mowing or cultivation, fewer tractor hours and lower labour costs.