Vineyards’ Drip Irrigation: When Conservation isn’t Conservation

by Mark Scaramella

In the 1990s at the beginning of the northcoast’s Second Big Grape Boom the local Wine Industry told us that they were conserving water by using drip irrigation instead of overhead spraying like conventional fruit growers still do. Everything else being the same, drip irrigation certainly uses less water than overhead spraying. But that’s not all there is to it.

Drip irrigation or no, the grape growers continued to build bigger and bigger ponds to irrigate more and more grapevines. Most of the water right applications for these ponds said “frost protection” not drip irrigation.

But the ponds are obviously for both frost protection and drip irrigation.

As long as you keep the size below 50 acre feet of water storage per pond there’s no permit of any kind from any government agency required. And 50-acre feet is a huge pond. You are supposed to apply to the County’s Planning and Building Department for a permit exemption saying that you want to build a pond smaller than 50 acre feet, but nobody checks to see what size you actually dig nor how much water goes into the pond nor where the water in the pond comes from.

Technically, you’re not supposed to store water pumped directly from a river or stream and you’re not supposed to build your pond in the middle of a stream. But once the water is in the pond, all you have to do is say, “Oh, that’s run-off,” and who’s to argue?

But is drip irrigation really conserving water? Is it even irrigation?

You may have noticed that most of the newer vineyards going in these days are what can be called “wall-to-wall” vineyards. Every plantable patch of dirt has vines on it. Sometimes the vines are even on the boundary fence.

Older vineyards, both in the US and in Europe, were dry farmed. They were not planted in the new industrial style which uses very narrow rows between the vines which are planted on every possible acre. Many of the old vineyards are dry farmed without any irrigation because, as vines naturally mature, they developed long tap roots down more than ten feet to take their water from the ground.

But, of course, that approach will only sustain so many vines per acre. If you jam your vines into every nook and cranny of your vineyard acreage the vines will compete for available underground water and none will get enough.

Solution: drip irrigation.

A UC Davis viticulture and enology professor named Larry Williams has changed the face of viticulture in recent years and his ideas are being widely accepted. Williams recommends that drip irrigation be used not to conserve water but to maximize output and control the growth of the vines with artificial injections of chemical-laced water.

Williams’ recommendations have become standard industry practice in recently planted vineyards making the new grapevines very dependent on the drip.

Using Williams’ method, “riparian rootstock” is planted very densely with roots that are specially developed and selected to be shallow, not deep tap roots like old-style vines.

With shallow roots, vineyard managers can plant lots more grapevines per acre because these high density industrial vineyards don’t need tap roots — they are watered with pond water and the ripening process can be carefully manipulated and ripened with the amount of water or chemicals applied.

Vineyard managers can apply special growth accelerators, as well as pesticides and insecticides via the water carefully dripped on the vines.

In Europe, where most grapes have been dry-farmed on very old vineyards, 450-500 vines per acre are common. Some people think of these gracious old-style vineyards as romantic and quaint.

But in the last few years the production of wine is about as romantic as the production of a bottle of Coca Cola.

Under the Williams method of dense planting, artificial watering and chemicalization, vintners can cram up to 2,500 vines onto an acre, producing much greater tonnages of grapes per acre and paying off their expensive vineyard development loans sooner.

Thus, the modern production vineyard makes money, unless, of course, there’s a grape glut, which happens every few years. Gluts push marginal growers out of business. And they are likely to be more frequent under these new high-intensity vineyard management practices.

Shallow riparian rootstock is also known to be much more vulnerable to disease such as phylloxera because shallow-rooted vines are right at the depth where the deadly nematode likes them. This, in turn requires more pesticide.

The huge new vineyard ponds that we see cropping up all over the County — which taken together capture more creek water than a dam would — are an essential element of the wall-to-wall grape plantings in the recently developed vineyards.

In fact, these new vineyards are designed not to conserve water but to require much more water — water that is becoming scarce everywhere on the Northcoast.

Further, if you can produce wine grapes with pond water like you can keep an ICU patient alive with a drip, you can plant more grapes, on steeper slopes and in areas with dryer climates, demanding even greater amounts of water to keep them going.

What was once thought of as conservation has become anything but.

And there’s almost no regulation or restriction on any of it because, even though the product being generated is nothing more than another of the expensive intoxicants that Americans can’t get enough of, it’s considered to be “agriculture,” just like apples or potatoes.

But, as Deputy County Counsel Frank Zotter recently said when he was trying to force the Point Arena Parrot Breeding People off their tiny coastal acreage after they claimed that raising parrots was agriculture, “Mendocino County defines agriculture as the production of food or fiber.”

Since wine is neither food nor fiber, why is making it considered “agriculture”?

If wine making is agriculture, so is marijuana growing.