Tips for no-tilling into heavy corn residue
Often producers are concerned about no-tilling into fields with large amounts of residue. The residue needs to be properly spread behind the combine during harvest of the previous crop, preferably with a straw chopper and proper chaff distribution. Minimize any residue disturbance (rolling stalk chopping or shredding) before or during planting. Leave as much residue anchored, attached, and standing upright as possible. That way you don't have to handle it and when you do run across it, the soil holds it so that the equipment can pass over it. The time and place to precondition corn residue is during harvest using knife-edged snapping rolls on the combine with the head running about 6 inches off the ground.
Today's planters have no trouble planting through heavy residue as long as weight has been added to the row units so they don't ride up over the residue, leaving the seed on the soil surface. For most planting conditions, raise residue movers so they run about 2 inches above the soil surface. At this height, they act as a "V plow" to lay the stalks to the side so that you only have to cut the stalks near the base.
For corn planting, set the depth control for about a 2.5- to 3-inch planting depth on bare soil so that when the depth gauge wheels run on the residue and over the root stumps, you are still putting the seed into the soil to at least a 2-inch planting depth. This is why weight is added to the planting units. Slow the planter to 4.5 or 5 mph so that you don't bounce over root stumps and add a "walking beam" depth control stop to John Deere planters if they don't already have one. If your double disk seed furrow openers are sharp and working together, they will cut down through the old root stump and put the seed into soil, even through residue from 250 bu/ac corn production. (Remember, the root mass you see forms about 1 inch above the seed at the nodal roots.)
For no-till, especially under heavy residue conditions, put a pop-up fertilizer in furrow, regardless of the soil phosphorus level (ie: 5-7 gal/ac 10-34-0). With the heavy residue, the soil may be a little cooler than if you moved the residue aside so the slower growing roots may have a temporary nutrient deficiency. The pop-up gets that seedling going and overcomes that problem.
Research in Minnesota on flat, poorly drained soils showed a yield response to pop-up fertilizer in heavy residue (regardless of soil phosphorus level) and showed a yield response to moving some residue out of the row, but not an additive effect. For Nebraska's conditions, most no-tillers should use the pop-up because shortly after planting, they will wish they had the residue back over the row to reduce soil crusting, conserve moisture, and reduce erosion. Also, disturbing the residue at planting makes planting much more difficult if the soil is wet under the residue. Without disturbing the residue, the depth gauge wheels of the planter ride on the residue and don't mud up, making planting depth much more uniform.