Impact of Minimal Vineyard Irrigation Strategies on Soil and Plant Sustainability

Citation

Land & Water Australia. 2008. Impact of Minimal Vineyard Irrigation Strategies on Soil and Plant Sustainability. [Online] (Updated March 8th, 2010)
Available at: http://lwa.gov.au/node/2333 [Accessed Thursday 2nd of September 2010 04:53:32 PM ].

The techniques developed by Clarke (2003) will be used to quantify and then model (eg using LEACHM & VineLOGIC) the long-term impact of irrigation with moderately saline irrigation water using a range of drip application techniques in combination with different surface soil management approaches on soil chemical & physical properties, plant physiological performance and wine grape quality through wine and analytical assessment.

The primary research site will be the existing experiment on the Orlando Wyndham vineyard at Langhorne Creek SA; other sites will be used as required. The model will be used to predict the outcomes of similar irrigation strategies at sites with different soils and irrigation water quality. Findings will be extrapolated to other perennial horticultural crops in the Murray Darling Basin.

Aims

Quantify the soil salinity profile under a range of irrigation application & soil management practises in a wine grape vineyard in the lower reaches of the River Murray at Langhorne Creek SA.
Assess the effectiveness of winter rainfall in leaching accumulated salts from vine rootzones irrigated with differing irrigation application systems.
Determine the effects of these management practices on crop water use, vine performance and winegrape quality.
Develop simple predictive models to test and identify a range of management scenarios that will minimise vine rootzone salinisation without significantly increasing vineyard irrigation requirement.

Outcomes

Practical vineyard management options that:

maximise vineyard water use efficiency
minimise long-term vine rootzone salinisation under precision irrigation application techniques.
enable wine grape growers to confidently grow grapes to winery specification using environmentally sustainable production systems

Background

Environmental pressures such as salinity and prolonged drought condition in the Murray Darling Basin have created a widespread recognition that irrigated water consumption has to be reduced to an environmentally sustainable level. Recently developed irrigation techniques such as drip irrigation and RDI have achieved widespread adoption and there are now about 100,000 ha of drip /micro systems irrigated vineyard in Australia. The winegrape industry is aiming to further improve WUE through other management techniques such as the use of surface mulch, Partial Rootzone Drying, subsurface drip irrigation and sophisticated soil water monitoring technologies.

There is some evidence that reducing the irrigation volume through precision irrigation techniques may have long-term negative impacts. In low rainfall areas where winter leaching is not sufficient, reduced irrigation could result in excessive salt accumulation in the root zone and also impact on soil properties, eventually compromising vineyard health and economic sustainability. A number of alternatives to the traditional drip irrigation approach of a lateral line suspended on a wire about 30 cm above the soil surface have been proposed in an effort to reduce soil structural decline and rootzone salinisation. Subsurface drip irrigation may provide potential benefits in situations where moderately saline water is used for vineyard irrigation such as in the lower reaches of the Murray Darling Basin.