Managing soil salinity for wine quality in groundwater-irrigated vineyards
This project, using the Padthaway district as a case study will produce strategies to adapt (with time) the crop production system to the prevailing soil & climatic conditions, groundwater flow & quality regime and irrigation technology to achieve premium wines that continue to meet world food health standards and hence ensure export growth.
Rising rootzone salinity in vineyards, drip irrigated with moderately saline underground water is placing the sustainability of such vineyards at risk. This interdisciplinary project will deliver a pathway to sustainability for groundwater-irrigated vineyards, about 50% of the national grape growing regions.
Besides scientists, this adaptive journey will involve close participation of growers, winemakers and natural resources managers to the benefit of the public at large, both in Australia and in our export countries.
Component 1: Hydro-geology scenarios for the Padthaway district
- Review previous work undertaken by DWLBC (2005) and subsequently and Aquaterra (2007)
- Develop a district groundwater model with allowance for solute transport from the unsaturated zone
- Integrate the outcomes of the study component 2 and 3 and any special requirements from component 4 into the future groundwater scenarios.
Components 2 & 3: Root zone salinity management and soil structure decline
- Quantify the effect of 10 years of drip irrigation on the soil salinity build-up and soil structure decline in a long term CSIRO rootstock trial site in the Orlando Wyndham‘s Lawson vineyard.
- Compare the current soil properties at the Lawson site with those determined by CSIRO L&W in the 1990’s and Wetherby (2005). (CSIRO in-kind comprehensive soils data from rootstock trial at Orlando Wyndham’s Lawson vineyard eg EC1:5, pH, cation and anions in soil solution).
- Develop management options for reducing root zone salinity by using Hydrus 3-D model of salinisation processes in drip-irrigated vineyards, especially on Padthaway soil types.
- Initiate field trials to validate the identified root zone management tools and techniques for reducing root zone salinityIn partnership with industry, establish a network of monitoring sites for soil salinity and grape juice quality in the Padthaway, Coonawarra, Wrattonbully and Mount Benson districts of the Limestone Coast GIC.
- Determine regional trends in soil salinity and winegrape performance in those districts
- Determine guidelines for minimising the effect of soil salinity on wine quality based on outcomes of field experiments, literature review and monitoring
- Pro-actively communicate via workshops and published information the project progress and outcomes to the Limestone Coast regional and national viticulture industries.
Component 4: Rootstock selection for premium grape growing
- This component comprises the existing GWRDC project CSP 06/05 “Grape juice composition and sensory quality of wine from salt excluding rootstocks and characterisation of the chloride exclusion mechanism”.
- New practices for managing root zone salinity and protecting soil structure
- Recommendations on salt excluding rootstocks for quality grape growing by informed and confident growers in the Limestone Coast region and other similar situations nationally
- An integrated approach for sustainable, groundwater-based irrigated crop production systems that is tailored to the regional hydro-geology, soil types and crop production, demonstrated in a real-life example that is potentially applicable to other ground-water based horticultural regions
About 50% of Australia’s vineyards are irrigated with groundwater. Many groundwater basins have been overcommitted due to irrigation expansion and now feature steadily rising water salinity. Precision (drip) irrigated vineyards at nearly 100% WUE has the added disadvantage of rapid build-up of root zone salinity. The wine produced in those areas has started to exceed the Sodium Chloride (NaCl) permissible threshold for export markets. The $3 billion wine export is potentially at risk of being discredited for health reasons