Mint Farmers Save Water & Fertilizer with Drip Irrigation

Original article posted on Capital Press (Sean Ellis)

The first three Idaho farmers to use a drip irrigation system on mint fields reported mostly favorable results after the second season, but they did face a few problems with the new practice.

As a result, the Idaho Mint Commission is financing a three-year trial at University of Idaho’s Parma research station to further refine the practice.

Nampa farmer Robert McKellip, who last year was the first Idaho farmer to put mint on a drip system, said he used about 2 feet of water per acre on the 56-acre field this year, compared with the typical 5 acre-feet for a field that is furrow irrigated.

He said he also used a lot less fertilizer and yields were great.

“I’m really pleased with it,” said McKellip, president of the Idaho Mint Growers Association.

McKellip said the drip system proved its worth this year on water savings alone. The 2013 growing season in the Treasure Valley was marked by a tight water supply that caused several irrigation districts to shut off water a month early

If all farms in the valley switched to drip, “we’d never, ever have another drought,” he said. “I”m using less water on my mint drip system than I’d use during a drought year.”

Hamanishi Farms in Fruitland put a 70-acre mint field on a drip system last year. The field used about 25 percent less water and 50 percent less fertilizer than a furrow irrigated field, said farm manager Jon Fabricius.

But an anticipated 50 percent labor savings never materialized and labor costs actually increased because gopher damage resulted in a lot of maintenance on the drip tape.

“Our labor costs have probably doubled compared with a sprinkler system,” Fabricius said. “It’s pretty high maintenance.”

Other than the labor costs, “The rest of it has looked pretty good,” he added.

Greenleaf farmer Dave Dixon put a drip system on a mint field that was cut twice last year. After the initial cutting, dry spots started appearing in the field, a result of the plants’ roots penetrating into the drip tape.

Dixon tried to fix the problem but started seeing dry spots again this year and ended up abandoning the drip system and going back to sprinklers.

The reduction in water and fertilizer use was promising and mint on drip systems is probably where the industry is headed, he said. “But I’m gun shy about the possibility of root intrusion. It’s something we have to get figured out.”

The Parma trial is designed to figure issues like that out, as well as determine how to apply pesticides through a drip system and figure out exactly how much fertilizer and water savings a drip system results in, McKellip said.

“I think as people figure out how to do it, you’ll see more and more mint acres going to a drip system,” he said. “It’s something that’s never been done before with mint and there’s a learning curve.”

Click here to learn more about Robert McKellip’s experience with drip irrigation on mint.