A dry farming trial produces some success

In mid-May, as soon as the sun came out and the soil warmed, Teresa Retzlaff dug into the earth at 46 North Farm. She filled holes with seeds and starts of zucchini, dry beans, summer squash and more. She covered the holes with soil and made sure the beds were free of weeds.

And then, she walked away.

About 10 miles down the road, the same thing happened at LaNa Conscious Farm. On a 2,000-square-foot plot of land, Larry and Nancy Nelson’s field was filled with the same plant varieties and, aside from light weeding, was left untouched.

Now, in late August, the starts have grown to produce-bearing plants. The zucchinis’ wide leaves shade dozens of vegetables, the full-sized tomatoes are ripening from green to red. One of Retzlaff’s winter squash is more than 2 feet long.

All of this happened without any irrigation.

“I didn’t really think it was going to work,” Retzlaff said. “I kind of thought they’d all be dead in a few weeks and they weren’t … It was phenomenal.”

The process is called dry farming. Farmers who practice it do not irrigate their plants throughout the dry summer season. Aside from occasional rainfall, plants rely only on moisture from below the surface to sustain growth.

It’s a historic agricultural practice, but until recently it has remained widely unheard of on the Oregon Coast.

In 2015, Amy Garrett, an assistant professor at Oregon State University, kick-started a dry farm trial that now stretches across the state. As of 2019, three farms on the coast participate in the trial, two of them just a short drive from downtown Astoria.

“It seems like the coast is a really good place for dry farming, mostly because of the climate,” said Matthew Davis, the project coordinator at Oregon State for dry farm site suitability. “It’s a lot cooler on the coast … It’s just a more forgiving place.”

Davis began working with the project in May under professor Alex Stone and alongside Garrett. Their research is ongoing.

Davis visited both North Coast farms in May, where he installed plants and soil moisture monitors. The monitors are inserted and left in the ground, where the small white rods and green cords help scientists and farmers know how much moisture is being held in the soil below.

“Dry farming doesn’t mean that no water is used by the plant,” Davis said. “Water is stored in the soil, it’s held there.”

The farm’s soil type controls how much water is held. On the coast, moist soil and a high water table, coupled with the cool, damp climate is the reason both farms have seen success.

“The plants are less stressed, I think, in the coastal environment,” Garrett said. “Teresa was kind of our pioneer there.”

Quality, not quantity

Retzlaff got involved with the project in 2016, and has dry farmed a portion of her plants ever since. This year, she is dry farming eight rows of produce for the trial’s research and 10 additional rows on her own.

Dry farming is not a yield-maximization strategy. In order for dry farming to work, plants are plotted more sparsely to decrease competition and help ensure each plant’s roots has access to enough water.

“You can’t plant as densely as you would if you are irrigating,” Retzlaff said. “Because all the moisture they have is just what’s in the soil.”

But for Retzlaff, her main goal isn’t the quantity of produce, it’s the quality.

Dry-farmed produce typically has a stronger flavor and a firmer texture. Retzlaff strongly prefers the taste of her dry-farmed crops.

Oregon State’s small farms collaborative conducted blind taste tests, where consumers and farmers preferred the dry-farmed produce over the same variety that was irrigated.

“They have a very intense flavor because they’re not watery,” Retzlaff said. “Because you’re not watering them.”

Last year, 46 North Farm sold their dry-farmed produce to local restaurants. The Astoria Golf and Country Club’s kitchen bought more than 80 pounds of dry-farmed zucchini and squash.

“They had a really nice, concentrated flavor,” said chef Gehrett Billinger, who used the produce on specialty dishes, to create kimchi and to flavor beverages and meat marinades. “It’s a really really delightful flavor.”

“And,” he said, “I like that it uses less resources.”

Resource conservation is one of the aspects that initially sparked the dry-farmed trial, and it’s a theme that keeps farmers and researchers coming back year after year. As the climate changes, summer water availability has become a pressing issue.

“It’s of more interest now because of drought and decreased summer water availability,” Garrett said. “A lot of people are looking at alternatives to irrigated crop production in our dry season.”

The farmers that participate in the trial meet annually to discuss how specific crops weathered the dry season and exchange ideas to improve the next year’s yield.

“I think that this collaborative approach of adapting to a changing climate is super important given the predictions for summer water availability into the future,” she said. “We’re going to see a lot less of it.”

Coastal farmers, whose summer season is cooler and wetter than farmers in the Willamette Valley, are still paying attention to summer water access.

“Water is one of those resources, I feel like especially out here on the coast, we really take for granted because it feels like it’s so abundant,” Retzlaff said. “Just because you have a lot of it doesn’t mean you have to use all of it.

“If you’re a farmer and you’re irrigating with that water or you’re pulling that water out of a creek or a stream in August, that’s water that’s not being left in a waterway to help fish habitat and wildlife habitat. I think the more we can share with wildlife habitat, the better.”

Inherent risk

Retzlaff recognizes that not all farmers can practice dry farming. There is inherent risk with the technique. It requires fertile, moist soil and more land to produce the same yield. For some crops, dry farming is not a profitable practice.

“Part of the learning curve is finding out which crops you can break even on,” she said. “The zucchini has more than paid for itself already,” as have some of the squash varieties.

Other products, such as the dry beans, won’t make it to the public market, but will feed the 46 North Farm team throughout the upcoming season. Retzlaff will likely harvest just one or two melons per plant this year.

But even without the high yield, she saved time and money by not paying for water or labor to irrigate the plants for months.

“I feel like that’s profitable,” Retzlaff said. “There’s also the knowledge. To me, that’s a huge return on investment.”

There is also an economic incentive. On the Nelson’s farm, their winter water bill is typically around $35 a month. In the summer, that bill can be up to $250.

“I am fascinated in growing things without water because water is a big expense,” Nelson said. “The dry farming for me is just another aspect of the farming itself. It’s another tool in the tool shed that we can utilize to grow some things less expensive.”

Both farms still irrigate the majority of their crops, but they are hopeful to continue transitioning and evolving their dry farming for many seasons to come.

“The more that I can do dry-farmed, the more that I will do,” Retzlaff said. “It’s less of a resource that we’re pulling on, and I honestly feel like the plants are better for it.”