Breaking Up Compaction

Dustin Farr, Agrowplow Canada sales manager for R.A. West International Inc., says, “Agrowplow found that no-till works well, but after a decade, yield begins to decline because we’re creating man-made compaction that impacts rooting and yield. By running a subsoiler plow, we can fracture that compaction layer wherever it is located.”

Farr explains the tool not only relieves soil compaction, but by not mixing the soil, it maintains the integrity of the A, B and C horizons in the soil profile and natural productivity of the soil. This is achieved by equipping the Agrowplow with straight vertical shanks spaced 13 inches apart instead of the more standard 30-inch spacing.

“Our Agrowplow can penetrate to a depth of 20 inches, cut a slot only an inch wide, lift the soil profile 4 to 5 inches, fracturing compaction while creating a wave traveling across a field,” Farr says. “But there is no heaving and mixing like with a conventional parabolic shank. Our unit allows complete profile fracturing across the width of the machine. Other rigs have 30-inch shank spacing, and you have to make a second pass offset by 15 inches to completely fracture the profile.”

Check compaction. To determine if compaction exists, look for sloughs or depressions that won’t naturally drain or for yield depressions on a yield map. Then, Farr recommends using a penetrometer in the field to locate compaction. “Push it [the steel probe] in first under a fenceline to ‘feel’ what a natural, noncompacted soil feels like. Then, go out into the field, away from headlands, into areas of poor drainage of compacted soils, and push the probe into the soil until you hit the compaction layer, and record its depth. Then, dig a hole with a spade to look at the vertical profile. Use a knife to begin to probe the profile face and observe the density layer.”

Agrowplow recommends dropping the shank 2 inches below the compaction layer. Fall is the best time to open the soil and fracture compaction layers, as snow, freezing and thawing will help break up any remaining compaction. Farr suggests operating the tool at 31⁄2 to 4 mph. “Going any faster just means more soil mixing,” he says.

“Growers do not have to subsoil every year,” Farr adds. “Instead, we recommend a five-year rotation, plowing 20% of your acres yearly. If you monitor regularly for compaction, you will begin to notice the soil begins to tighten again by the fifth year. And we always recommend growers leave a check strip so they’ll see the effects of the compaction on the crop.”

The Agrowplow comes in multiple configurations from two to 19 shanks, with a straight-edged coulter to cut sod and residue. It’s available in a three-point hitch or pull-type model, and comes with either gauge wheels or cylinder stops that set and maintain depth. The Agrowplow is a subsoiler, so in high-residue crops like corn and wheat, the residue needs to be managed and sliced beforehand so the material will flow through the shanks.

For more information, visit www.agrowplow.com.

The information provided is general only and should not be taken as a professional recommendation.

If you have a question, e-mail Dr. Daniel Davidson at askdrdan@telventdtn.com

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