June (No. 497)
Irrigation audit feeds efficiency improvements
The November 2004 Vineyard Irrigation feature issue of Grapegrower & Winemaker carried a competition for New South Wales grapegrowers, in conjunction with the NSW Department of Primary Industries. The competition offered the services of a NSW DPI irrigation officer for a day’s audit at the winner’s vineyard, plus preparation of a written report. The competition was won by Peter O’Meara, of Adina Vineyard in Lovedale. In April, NSW DPI irrigation officer Gary Creighton and Michael Porteus, of WaterWise on the Farm media, visited Peter’s vineyard near Pokolbin. This article, written by Porteus, reports on the audit, its findings, and how the audit will assist Peter’s future vineyard operations and business plan for growing quality grapes and olives at Adina Vineyards.
A WaterWise on the Farm irrigation system efficiency audit has identified priorities which could help a Hunter Valley vineyard improve water-use efficiency by more than 10%.
WaterWise on the Farm audited the drip irrigation system at Adina vineyard in Lovedale near Pokolbin after its owner Peter O’Meara won a competition for NSW grapegrowers in the Australian & New Zealand Grapegrower & Winemaker.
The audit found the vineyard’s recently-refurbished irrigation system was delivering good flow rates and mains pressures.
But a catch-can test found that distribution uniformity (DU) on the vineyard’s 10 irrigation blocks ranged from 81.5 to 94.5%.
“DU measures how evenly an irrigation system is delivering water across an irrigation block,” said NSW Department of Primary Industries (DPI) irrigation officer, Gary Creighton.
“Low DU means the system is delivering either too much or too little water to different parts of the block. This wastes water and power, and potentially compromises yield and crop quality.
“On the other hand, high DU enables more accurate irrigation scheduling to improve efficiency and grow better grapes.”
WaterWise on the Farm advises that drip-irrigated vineyards can aim for Dus around 95%. The audit shows that Adina’s drip lines are delivering better-than-expected uniformity for equipment up to 16 years old.
And Peter O’Meara was indeed pleased with the crop harvested at Adina this year. However, he says the findings of the audit will feed into his planning for the property.
The audit also measured the irrigation system’s performance around the three capacitance soil-moisture monitoring probes recently installed at Adina. The results will help the vineyard calibrate the graphs produced by the telemetric monitoring system.
Responding to the vineyard’s concerns, the audit also looked at the growth of primrose weed and filamentous algae in farm dams and found that although the infestations are not currently hampering irrigation system performance, a range of mechanical and chemical techniques has been outlined for their control.
The audit also identified where improvements in mounding and mulching on some soil-types at Adina could improve infiltration to make more water available to vine roots.
NOTE: The complete article can be found in the June issue of The Australian & New Zealand Grapegrower & Winemaker.