An increasing pressure on water supply in California is driving vintners to trial more accurate methods to measure evaporation rates from the state’s vineyards.
The Californian wine industry uses on average 6-7 gallons of water for one gallon of wine
During a discussion on “sustainable” viticulture practices in California during the inaugural California Wine Summit from 1-4 October, both Steve Lohr and Matt Gallo stressed the challenges surrounding water use in California, before sharing their company’s responses.
“Water is precious and limited and so you have to manage it very precisely – you don’t want to under or over provide,” began Matt Gallo, head of winegrowing at Gallo Family Vineyards.
As a consequence, he said that Gallo has fitted soil moisture monitors at his company’s vineyards that send information to databases, which, in turn, schedule irrigation according to each vineyard’s needs.
Furthermore, he explained that satellite imagery is giving Gallo information on vine vigour which, when combined with soil maps, allows the company to see which plots are too vigorous and which are under performing.
Together, he said such information has allowed Gallo “to make more accurate decisions around water, pests and stress.”
Meanwhile, Steve Lohr, CEO at J Lohr Vineayrds said his business has taken several steps to conserve water in both the vineyard and the winery.
He said J Lohr currently use 3.5 gallons of water (16 litres) to produce 1 gallon of wine (4.5l) compared to an industry average of 6-7 gallons of water for one gallon of wine.
J Lohr uses squeegees to clean winery floors rather than hoses
Halving water use at J Lohr has required a number of small changes, such as using high-pressure nozzles on winery hozes and timing barrel washes to 45 seconds, as well as using squeegees to clean floors, rather than large amounts of water from low-pressure hoses.
Then, in the vineyard, Lohr said that “pressure bombs” were vital for the more accurate measurement of a vine’s water needs.
By measuring the water pressure in the plant, these instruments can tell how stressed the vine is, and therefore the amount of water required vine by vine.
“Last year we had four inches of rainfall over the entire year, when the normal is 12-14 inches, so we don’t want to put in any more water than necessary,” said Lohr, highlighting the limited amount of rainfall in California.
He also said he was trailing a new method of measuring the evaporation from an entire vineyard using an instrument suspended above the vines which can calculate the total water loss from a 5-acre area.
Concluding he said, “There is a water crisis right now, and everyone is going to have to use sustainable practices soon because regulation is coming their way.”