Farmer's dirt stays rich because of special tactics on farm near Northfield

Now in spring, with corn and soybeans soon to be planted, the Farm Boy is itchy again.

That's the way Dave Legvold described himself the other day — Farm Boy — while recalling the move he made with his family in 1976 from Bloomington to the relative hinterlands near Northfield.

"I grew up on a Rice County dairy farm and just wanted to get back to farming,'' Legvold said. "So after we moved from Bloomington we lived in a trailer house on the farmland we bought while I built our house.''

Legvold, 74, was honored recently by Gov. Mark Dayton for his innovative and persistent conservation efforts on the approximately 800 acres he farms, about two-thirds of it rented.

A teacher of environmental studies, science and physical education in the Richfield School District for 35 years, Legvold and his wife, Ruth, believed a move from the suburbs to the country would be good not only for them but for their sons, Michael and Mark, who at the time were in grade school and kindergarten, respectively.

In addition to teaching, and for many years farming while he taught, Legvold has been education director at Eagle Bluff Environmental Learning Center and executive director of the Cannon River Watershed Partnership.

Yet he seems uninterested in retiring. "Jump in,'' he said, inviting a visitor to join him and two of his family's three golden retrievers in an all-terrain vehicle for a tour of the home place.

Energetic in the manner of an evangelist, yet as politely reserved as a Norwegian farmer is expected to be, Legvold for many years has tilled the soil with conservation in mind.

"Originally, we planned to be organic farmers,'' he said as he piloted his John Deere Gator over cropland covered with waste from last year's soybeans that shielded the soil like a blanket, protecting it from erosion.

"But not long after I started farming,'' he added, "I discovered the soft underbelly of organic farming: It requires a tremendous amount of tillage, and I noticed my soil was washing away.''

In 1983, Legvold began practicing no-till planting, a subset of conservation tillage, a catchall farming category whose goal is to leave at least half of a crop's residue on the soil.

"When I started no-till, I didn't have the equipment to do it, so I rented it from the Soil and Water [Conservation District] folks,'' Legvold said.

About a century ago, Legvold's 175 acres were part of what was known as the Great Greenvale Township Slough. Over time, the area was drained and planted. Still, low muddy spots remained when the Legvolds bought the property.

Seven acres of the wet areas were retired for wildlife. The rest dried up as Legvold replaced the farm's old subsurface tiles with a modern pattern-tiling system.

Though necessary on some farms, subsurface drainage systems worry many conservationists. And rightly so: Draining surface water from hundreds of acres quickly through a series of underground pipes before dumping it — and the fertilizer and other farmland chemicals it carries — into a nearby stream or ditch is one reason Minnesota is a major contributor to the nitrogen-induced "dead zone'' at the mouth of the Mississippi River.

Near a small creek that forms one boundary of the Legvold farm is a metal box that in many ways stands as a beacon of hope for Minnesotans concerned about the state's clean water — or lack thereof.

Nondescript in appearance and simple in design, the box houses a manually operated control system that can withhold subsurface water in the tiles (actually corrugated plastic pipes) that collect it, making the water available to crops as necessary. Or the box can divert the water horizontally through a corrugated pipe running underneath what is known as a "saturated buffer.''

The redirected water feeds the buffer's grass and other plants while allowing excess water to distill into the soil, a vast improvement from sending tile-collected water into streams or ditches unimpeded.

Such a control system isn't expensive, said Mark Dittrich, senior conservation drainage planner for the Minnesota Department of Agriculture. But saturated buffers must be at least 50 feet wide.

"With other partners, we helped develop the saturated buffer system on Dave's farm as an example of what can be done to manage water,'' Dittrich said.

Not all farms are appropriate for saturated buffers. Soil type and slope must be considered. Yet perhaps half of farms in some areas of the state might be suitable. And at about $4,000 for the control box and its installation, the system is affordable, especially considering that a 100-acre subsurface drainage system might cost $100,000.

Legvold's farm's was first in Dakota County to earn approval under the Minnesota Agricultural Water Quality Certification Program, said Brad Redlin, who manages the voluntary effort for the Department of Agriculture.

Legvold is proud of the designation. And happy, also, to note that conservation-minded farming can pay for itself, and more.

"My yields are comparable to other farmers','' he said. "But my costs are less. Instead of doing extensive tillage at a cost of 6 to 10 gallons an hour with big equipment, I'm burning about .6 of a gallon an hour.

"Most importantly, I'm preserving the heart of my soil, which is the organic matter. As long as soil has good organic matter, it can be farmed.''

Dennis Anderson danderson@startribune.com