Projects

Objective:

There is an aim to limit the amount of water that flows past the roots of vines (as well as other productive plants) and into aquifers and water courses. Drip irrigation and soil moisture monitoring technologies have helped reduced water lost past the rootzone. Now research is underway to determine any possible long term effects of drip systems on soil chemistry and physical properties.

Collaboration:

The Grape and Wine Research and Development Corporation is co-funding the research with the National Program for Sustainable Irrigation. Research providers undertaking the work include The South Australian Research and Development Institute and The University of Adelaide. 

Results:
While the project is at an early stage, studies to date have shown that soil structural and chemical change has not only occurred where moderately saline water has been used over a long period but also where high quality water has been applied. This suggests that other factors, apart from salinity, may contribute to soil decline where precision irrigation technology is applied. It is therefore important to understand what is driving changes, whether physical or chemical, and the conditions which promote decline. Then it may be possible to recommend practices which will avoid or minimise negative effects.

Although drip systems apply water sparingly, the soil is generally in a variable state of moistness during the actively growing period. This compares with a natural series of wetting and drying cycles under natural rainfall or when under partial rootzone drying (PRD) management. This has led researchers to include in trials a break from continual wetness to see if this assists maintenance of normal soil structure.

Measures of Success:

In Australia drip irrigation could be found on just a few properties in the 1960s, whereas today 76% of the 150,000 hectares of irrigated vineyards have drip or micro-spray.

Technologies have greatly improved grape quality as well as irrigation efficiency. For example, in the largest grape growing region, the Riverland, about a third of applied water drained away under furrow irrigation. Today the average “pass” of irrigated water beyond the rootzone is 15% in that region.

Growth of the Australian wine industry to capture expanding export opportunities would not have been possible without the water use efficiency and operational benefits provided by drip irrigation. The plus side of drip irrigation is well known but it is timely to ask if there are any down sides and correct those so that the benefits can continue in a sustainable manner.