For no-tillers who choose to use coulters, here are a few tips:

  1. If running a coulter, be sure to adjust it and run it above seed depth. “A lot of farmers never adjust the depth of their coulters,” says Andy Thompson, a territory manager with Yetter Mfg. 
         “If you’re going to use a coulter, put new V opener blades on, put brand new coulter blades on, and then level the planter and adjust the coulter so it’s ¼-3/8 of an inch above the bottom of the seed depth. Then at the end of the season, go through and adjust as needed for the next year.”
  2. If choosing to use a coulter, be sure to place a residue manager in front of it. “The goal is to never penetrate the soil until after the residue is moved — that’s our best-case scenario,” Thompson says. “If we don’t do a good job with that and there’s residue in the way when the coulter comes through, we’re much more likely to get hairpinning.”
  3. Advertised seed trench widths are approximate and relative to speed. Higher-than-average speeds will result in more soil disturbance. For instance, a 16-inch 13-wave coulter may have an advertised seed trench width of 1 inch, but if the planter is running at 8-10 mph, Thompson says, the seed trench will be more like 2 inches. 
         “It’s kind of like if you were to vibrate you fingers in water,” says Thompson. “The faster you wiggle your fingers, the further the waves move outward.”
  4. Sharpen coulters as needed. If the soil is dry and hard, coulters may not need to be sharpened as often as when soil is wet and soft. But how sharp is sharp? Coulters that are too sharp will chip or bend easily, so the best bet is to keep them sharpened to a 45-degree angle.
  5. Ultimately whether or not coulters are beneficial depends on soil condition and planter operation. By driving too fast and making a wide cut, you’ll have trouble adequately covering the seed furrow.
  6. You also need enough weight to get the coulter into the ground — 500 pounds per row is a rough guideline. Add-on weights and adjustable pressure can help, but you’ll need to experiment with your own soil types and residue conditions to find the exact amount of weight.
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