Renewing the Countryside: Washington

The yellow revolution
In eastern Washington, potato farmer Dale Gies has pioneered the use of mustards to build soil organic matter and eliminate the need for chemical soil fumigants.

By Ingrid Dankmeyer
Excerpted by permission from the forthcoming book,
Renewing the Countryside: Washington.

Posted May 12, 2005

When Dale Gies decided 12 years ago to try rotations of wheat and mustard in between crops of potatoes on his family’s farm south of Moses Lake, he didn’t realize he was on his way to becoming a leader in the field of biofumigation.

Dale grew up on this 500-acre farm, a property his family has been intensively cultivating ever since irrigation allowed his father to break the ground out of sagebrush. Gies Farm primarily sells potatoes for processing, wheat and vegetable seeds, and grain corn. But over the course of 40 years, soil productivity declined due to wind erosion, low levels of organic material and compaction. Dale decided to experiment with changing his cropping system to improve soil quality by increasing water penetration and retention and reducing soil erosion.

He went looking for a cover crop that would improve soil quality without encouraging diseases ... and settled on mustard. Mustard plants had been shown in laboratories to have fumigant qualities, Dale knew, but those findings had yet to be successfully replicated in the field. “Some of the green manure crops cause disease, host nematodes, or become weeds themselves," Dale notes. "We knew mustard had the potential to help with disease and nematode control, but we didn’t realize it could be as effective as it has been. Really, we just wanted to protect the tilth of our soil while we were growing rather intensive crops like potatoes and onions that don’t produce a lot of residue.”

"We knew mustard had the potential to help with disease and nematode control, but we didn’t realize it could be as effective as it has been . . . Not only could we grow a high-quality product, but we are considerably over the county’s average yields.”

Dale describes his first trials: “I let the mustard grow up four to six feet tall, then in October I would chop it up and incorporate it back into the soil before planting potatoes. When I went back in and compared where we chemically fumigated with where we used a mustard crop, I didn’t see any difference.” After three years of consistent results, Dale contacted researchers at Washington State University, who then came out to do replicated trials in his fields. As the data began coming in, Dale recalls, the researchers response was, “Wow, this mustard works as well as fumigant!”

In addition to the biofumigation effect, Dale has seen other improvements, including an increase of more than 30 percent in the moisture-holding capacity of his mustard-managed soils compared to the same soils under conventional management. “The green manure does some rather unique things to the soil as far as structure and tilth," he explains. "And with the chemicals [produced naturally by] the mustard, we actually solved a number of weed, disease, and nematode problems.” Following a rotation of potatoes / wheat / mustard / potatoes, combined with minimal tillage, stubble mulch and green manure, Dale has seen his soil organic matter levels rise steadily—something generally thought to be impossible in a potato rotation. “The soil just keeps getting better!” he marvels.
Dale vividly remembers the day the researchers brought in a wind machine to replicate and test the impact of strong winds on his fields. “It looked like a giant vacuum," he recalls. "It has a big glass chamber you put down over the soil, and you keep turning it up and up and up, and you actually observe when the soil particles start to detach and move . . . They actually maxed the machine out on one of our fields that had had three green manure crops in the previous six years, and they couldn’t get the soil to move,” he says, smiling.

From green manures to seed production

"If we have to destroy the ground to make a living, we probably ought to go look for another job."

When Dale and the WSU researchers started testing different mustard varieties, they learned of a research institute in Italy that breeds mustards specifically for soil improvement and pest management effects. Most of the work done in the United States had involved taking mustards bred for edible purposes and then seeing if they had the desired effects in the field. Dale recalls, “We brought in some of the Italian-bred mustards to test, and when we began producing those mustard varieties ourselves, there was a lot of interest from others.” Dale now markets this seed through seed dealers across the United States and Europe. He comments, “What started out as just something to keep our ground in good shape has become almost a full-time endeavor for me. I spend a lot of my time now working with researchers and dealers and growers trying to figure out how to tweak this technique to make it really work in other areas.”

Over the years, Dale has reduced but not eliminated his use of fertilizers and herbicides. He does find that mustard helps to keep his nitrogen inputs low. “The mustard ties nitrogen up in the fall and keeps it in an immobile form all winter," he says. "Then in the spring when the soils warm up and you plant your crop, the nitrogen becomes gradually available to the plant, along with other nutrients.” Dale also carefully monitors water evaporation on his farm, and with judicious irrigation has almost eliminated movement of water below the root zone, reducing fertilizer waste and water pollution.

Chemical fumigants have been eliminated entirely on the farm. “That got people’s attention," Dale says. "Not only could we grow a high-quality product, but we are considerably over the county’s average yields.” He continues, “We don’t have some foundation funding our work, this all has to fund itself. We found it just makes good economic sense. We are able to grow higher-value crops, and we are doing it for less money.”

Dale carefully monitors water evaporation, and with judicious irrigation has almost eliminated movement of water below the root zone, reducing fertilizer waste and water pollution.

Dale has invested some of what he has saved into creating wildlife habitat on the corners of his fields beyond the reach of the center-pivot irrigation system. Pheasants are his primary customers. He explains, “We tried to put together all the critical elements of wildlife habitat: native grasses for them to nest in; shrubs that provide winter cover and protection from predators; and some berries. We plant food crops – safflower and corn – so that when we get a really nasty winter, we don’t lose all of our birds.”

While Dale is excited by what he has discovered on his farm, he doesn’t expect conventional farming practices to change overnight. “One of the things that researchers are finding is that it’s hard to get people to do green manures. If you can tell them it will reduce disease, weeds or nematode, they’ll do that, but not just to improve the tilth of their soil.” It pains him to see farmers baling and selling straw that won’t bring in $20 an acre, while their soils lose $60 to $70 worth of organic matter and nutrients on that same acre. “You’ve got to feed that soil and people don’t realize that,” he says. “There is more life in the 18 inches below the soil surface than in three feet above it. It’s like Will Rogers said, it’s not that we don’t know anything, it’s just that half of what we know isn’t true.”

Dale knows that farms like his are in the minority. But, he observes, “in our opinion, if we have to destroy the ground to make a living, we probably ought to go look for another job.”

Ingrid Dankmeyer writes and raises vegetables, fruit, chickens, ducks, goats and two daughters on a small farm in Battle Ground, Washington. She can be reached at ingrid@pacifier.com.