In no-till, planters need to cut and handle residue, penetrate the soil to the desired seeding depth, establish proper seed-to-soil contact and close the seed-vee. Keeping these four items in mind, producers can evaluate the strengths or weaknesses of their planter and make any adjustments or changes necessary to make no-till successful. Fortunately, most currently available planters can be used for no-till with few, if any, modifications when paying attention to the following tips.
Maintain sharp openers. Double-disk openers, if sharp and working properly, can cut through residue without coulters or residue movers. Adjust the disk openers so that they are working together as a single cutting edge with about 2 in. of blade contact. When replacing the disk openers, also replace the seed tube protector as it holds the disks apart to reduce blade flexing and acts as a scraper to help keep the disks clean. If hairpinning residue is a problem, increase the planting depth to improve the residue cutting angle of the disks.
Don’t seed between the old rows. Avoid planting in the heart of the wheel track as that is the most compacted area in the field. Also, when seeding between the old rows, some of the new rows will be in soft, untrafficked row middles with different soil conditions than the wheel tracks. Planting about 4 in. to the side of the old row works well for corn on corn. This also reduces tire wear compared to driving on the root stumps to plant between the old rows.
Monitor planting speed. Keep the speed around 4-5 mph to reduce planter unit bounce and deliver seeds uniformly. Be wary of ads that say a planter can "meter seed" at 7-8 mph. That doesn't mean it can deliver the seeds to the soil uniformly at higher speeds. Often the resulting non-uniformity from operating at higher speeds reduces yields enough to justify a larger planter (or a second planter) to complete planting in a timely manner.
Increase the down pressure. No-till residue requires down-pressure springs and extra weight (as necessary) on the planter to cut through and penetrate the soil to achieve desired seeding depth. This is especially true when working in hard, dry soil. Row units should have enough down pressure to ensure that the depth gauging wheels are actually gauging planting depth. Check the down pressure on the row units as conditions change to avoid over-compacting wet soils, creating sidewall compaction.
Place seeds at a uniform depth. Make sure all the seeds are at the bottom of the seed-vee, placed into good soil moisture, for uniform emergence. Keeton Seed Firmers or Schaffert Rebounders can provide a more uniform planting depth for more uniform emergence. These units also provide convenient in-furrow fertilizer application options. Keeton Seed Firmers also improve seed-to-soil contact, as the name implies.
Keep residue uniform. Consider residue movers on the planter to even up and create a uniform residue layer, especially if the residue was not uniformly spread during harvest. However, if the residue cover is already uniform, such as in long-term no-till, residue movers can do more harm than good. In these cases, the movers break residue loose from the soil. Some of this residue can then blow back over the row, creating non-uniform conditions. In addition, some emerging corn may leaf out under the residue and may have difficulty surviving.
Close the seed-vee. The seed-vee should be properly closed for good seed-to-soil contact and to reduce drying out of the seed zone. Spoked closing wheels are often added to planters to help close the seed-vee. They serve three purposes:
The loose soil created by the spoked wheels reduces the chances of the seed-vee opening back up as the soil dries. However, depending on your moisture situation, the tillage of the closing wheels might dry out the soil too much. In some cases, growers get better results using one spoked wheel and one regular closing wheel. Also, some closing wheel brands have less-aggressive spokes than others.
Consider planting deeper. Planting the seeds deeper puts them into a more buffered soil environment with a more uniform soil temperature and soil moisture. This improves uniformity of emergence, which increases yields. Also, by planting deeper, the root system is better established, improving standability and allowing the plant to better handle stresses. Corn should be planted at least 2 in. deep as most corn planters were designed for planting depths of 2-3 inches. Consider the 3-in. planting depth in dry years and low-residue conditions to reduce the chances of the seed zone drying out.
For more details, see Setting Planting Equipment for Successful No-till and Preseason Field Check for Planting Equipment in the April 2, 2010 issue of CropWatch and Recommendations for Avoiding Sidewall Compaction at Planting and Tips to Reduce Sidewall Compaction in the April 16, 2010 issue of CropWatch.