Berry News

Saving Water : New sprinklers irrigate strawberries more efficiently

Source: CENTRAL COAST FARM & RANCH | December 21, 2015

For generations, the typical strawberry field has been watered the same way early in the growing season: sturdy, rotating sprinklers on aluminum pipes, spraying jets of water 10 feet in the air and sending rivers of runoff between the rows of plants.

But what’s typical is changing quickly. High-efficiency, low-profile plastic sprinklers were introduced about a decade ago and have spread throughout the industry. In Ventura County, some of the biggest growers have been early adopters. They report reductions in their water usage of 60 percent or more during the month or so that sprinklers are used to help strawberry plants get established.

The biggest grower in Ventura County, Reiter Affiliated, was one of the first to adopt micro sprinklers and is working toward getting them for all of its farms in the area. The new technology helped Reiter use between 2 and 2.5 acre-feet of water on its farms in the Oxnard Plain last year, down from 3 acre-feet in the recent past, said Eric Reiter, the company’s vice president of operations for its southern district. Growers have no choice but to use less; the Fox Canyon Groundwater Management Agency has cut groundwater allocations for some growers down to 2.5 acre-feet during the drought.

There are many ways to reduce water usage, but few that come with the obvious public relations benefit that high-efficiency sprinklers bring. People driving by a field with the new sprinklers no longer see water shooting into the air and running off into the street, said Alvaro Valerio, a strawberry production manager with Reiter.

“It’s a little embarrassing,” Valerio says, of the runoff the old methods produce. As he says this, he’s standing between rows of strawberry plants at a Reiter farm in Oxnard. The sprinklers are on, but his boots are barely getting damp.

“With the old sprinklers, we wouldn’t be able to stand here,” Valerio said. He’d be ankle-deep, he said, in either a swampy muck or a flowing stream.

The micro sprinklers are less than a foot tall, while traditional sprinklers stand about three feet off the ground. The new models have advantages beyond water savings. They produce a mist of water, rather than a rotating spray, so they do a better job coating the plants to protect against frost, dust or mites. Plants can take a little longer to establish with the new sprinklers, but there’s no loss at all in their eventual yield, Valerio said.

James DuBois, a water resources manager for the marketer and distributor Driscoll’s, said more than half of the growers on the Oxnard Plain that distribute through his company have the new micro sprinklers. In the summer, during the secondary planting season, that figure is between 60 percent and 70 percent, he said.

The overall water savings has been enough to give all growers a noticeable bump in water pressure on United Water’s Pumping Trough Pipeline, which brings Santa Clara River water to farms on the Oxnard Plain.

“The establishment process of strawberries can be water intensive, especially in hot weather,” DuBois said. “You don’t have to go out and buy new micro sprinklers to use less water, but it sure is a really good tool.”

It’s not a free tool, of course. New micro sprinklers cost between $800 and $1,200 an acre, DuBois said.

“Even just a small grower, a 40-acre grower, that’s $40,000 in capital they have to put out, versus renting sprinklers for a fraction of that,” he said. “That is definitely a barrier to full adoption in the area.”

Since they’re plastic, the new sprinklers also aren’t as sturdy as the aluminum ones, though those aren’t exactly indestructible. Valerio said that one Netafim model Reiter uses is supposed to be good for seven years but often lasts longer.

Micro sprinklers are easier to install than the old models. The plastic pipes are much lighter than metal pipes, and they can be rolled out into the field, a much easier process than laying aluminum pipes.

That’s important because sprinklers don’t stay in strawberry fields year-round. A month or so after the plants go into the ground, they’re considered established, and the sprinklers are replaced by drip irrigation.

About eight years ago, DuBois said, Reiter tried establishing plants using drip irrigation from the start. “What we found was that it’s very difficult to establish strawberry plants without sprinklers,” he said. “But we also realized you probably don’t need as much water as we were using.”

High-efficiency sprinklers were adopted first by organic growers, as a pesticide-free way to keep dust and mites away. The new products eventually spread to conventional growers.

The speed with which growers have adopted micro sprinklers speaks to the general pace of change in the industry.

“The old farmer mentality was, ‘It was done this way when I grew up, my father did it this way, my grandfather did it this way,’” Valerio said. “Farmers now have to adapt to new technology.”