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Drainage keys agronomics for these Minnesota farmers

During his crop-consulting career, Mark Bernard has heard farmers complain about the costs of all kinds of inputs. Seed. Fertilizer. Machinery.

There’s the price of one input, though, that never raises a peep among farmers.

“I’ve never heard farmers complain that they put in too much tile,” says Bernard of New Richland, Minnesota. “Without good drainage on our soils, all other practices take a backseat.”

Tiling Unleashes Productivity

Tile drainage is a cornerstone for Duncanson Growers, Mapleton, Minnesota. Farm partners include Pat and Kristin Duncanson, brother Karl and wife Jackie, and the brothers’ mother, Mary.

The deep and black soils of this area aren’t what European settlers found when they trekked to southern Minnesota in the 1800s. “Our soils are old geologic lake beds, prairies and swamps,” says Pat. “They are silty clay, some with little loam in them.”

These swampy soils masked excellent farmland that emerged when settlers improved drainage. Some peat soils the Duncansons farm consist of 10% to 15% organic matter. That’s off the charts, as many Corn Belt soils top off at 4% to 5% organic matter or less.

This high amount enables soils to hold water during drought. They also can provide 20 to 30 pounds of nitrogen per percent of organic matter. High organic matter also protects against erosion and ensures excellent soil structure.

There’s a catch, though. Excess water that seasonally saturates these soils slows drainage and stifles tillage and planting. That’s where drain tile comes in. It persistently drains excess water from these soils, which creates a moist and warm seedbed that spurs germination and early growth. It also helps ensure timely planting, aiding the Duncansons in their goal of planting corn during the first week of April. Well-drained soils also help ensure timely spraying and harvesting, too.

“You can do nothing to control the weather,” says Pat. “But tile that removes excess water helps yields more than anything around here.”

Most of the Duncansons’ fields are pattern tiled. “In some cases, we take it to the extremes,” Pat says. “In some fields we have 30-foot tile lines; other fields have 40-foot lines.”

Increasing tile drainage has perked the recent interest of many other Corn Belt farmers.“When people started yield mapping their farms, they were able to put a dollar value on the costs of poor drainage,” says Bruce Erickson, a Purdue University agricultural economist.

Equipment Keys Timeliness

Equipment selection also enhances timeliness of field operations.

“You look around here and you see we just have a few pieces of machinery,” says Pat. “The planter is the most important piece of machinery we have. But we drive old pickups.”

If all goes well, their 48-row planter with 20-inch spacings can plant up to 500 acres per day.

“There is such a thing as having too big machinery,” says Pat. “But in southern Minnesota, we have a seven-day window on average to plant corn. We probably are oversized with a 48-row planter. But in some years, especially wet springs, it pays to have that extra capacity.”

Mechanically sound tractors also enhance timeliness.

“At planting, we don’t want to fool around with a broken hydraulic line,” says Pat. “With a seven-day window to plant corn, machines have to run. In the fall, we come in with a disk ripper to take care of cornstalks. So it’s critical that everything runs right for fall fieldwork, too. We upgrade our tractors regularly.”

This capacity enables the Duncansons to be patient during planting, a point echoed by their planter consultant, Kevin Kimberly, Maxwell, Iowa.

“He advises us to wait until conditions are fit to plant,” says Pat. “It’s hard to wait, especially when our neighbors are planting.” Waiting an extra day to plant, though, can reduce sidewall compaction in wet soils.

“The worst-case scenario is planting in wet weather and then having it turn dry,” says Pat. “We can have sidewall compaction, where the seed furrows won’t completely close.”

An in-cab monitor a automatically adjusts planter downpressure. “Too much downpressure can lead to sidewall compaction,” says Pat. “Too little downpressure is not good either.”

Optimum downpressure changes between soil type, fields, and even daily weather. “Good weather can cover up some planter errors, but we do what we can to reduce our dependence on ideal weather,” says Pat.

Once planted, liquid 10-34-0 starter fertilizer gives young seedlings the nutrients they need during early stages.

Narrow-Row Perks and Pans

The Duncansons have planted on 20-inch rows since 2006. Before that, they planted corn in 15-inch rows.

Narrow-row perks include equidistant spacing that allows plants to garner more sunlight and boost photosynthesis. Narrow rows also help blitz competing weeds due to early canopying.

In University of Minnesota trials, 20-inch-row corn has outyielded 30-inch- row corn by 7% to 9%. Yield increases with narrow rows have not always occurred in these trials, however.

Narrow rows also complicate planting by moving residue into a smaller area. “We have to have some aggressive row cleaners, but there is such a thing as getting too aggressive, too,” says Pat. “The residue can spill into other rows and clog rows by dragging and plugging.”

That’s particularly true for corn-on-corn, which make up around 40% of their corn acres. “Corn-on-corn is not as forgiving as corn-on-soybeans,” says Pat. “More residue complicates planting. It takes more nitrogen. If we make a small mistake, corn-on-corn can magnify it.”

Switching to 30-inch rows would boost residue flow within planter rows. Thirty-inch rows also create more combine options. “Twenty-inch equipment is more specialized and harder to trade,” says Pat.

For now, the Duncansons will stick to 20-inch rows, although they may reconsider when it’s time to switch planters. “We revisit this every year,” he says.  


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