When Nebraska Extension engineer Paul Jasa talks about planters, no-till and cover crops, people listen. Jasa has a wealth of knowledge, attained through research over the past four decades, that he brings to the table.  

At the Nebraska Soil Health Conference, held recently at the Butler County fairgrounds in David City, Jasa spoke about experimenting with no-till at the Rogers Memorial Research Farm east of Lincoln beginning in 1978, before planting cover crops had earned its way back into modern cropping systems as a popular practice.

Focusing on no-till planting with cover crops, Jasa answered four important questions no-tillers have about getting the most productivity from their no-till and cover cropping systems:

1. How deep should I plant? In a well-structured, no-till soil, don’t plant anything — including grain sorghum — at less than 2½ inches deep, Jasa says. “You will get more uniform stands when planting deeper,” he explains. “We plant corn at 3½ inches deep, and we’ll have better stands if we don’t move the residue.”

Penetrate the soil, and get seed where it belongs, Jasa advises. “In the 1980s, the planters were too light. Today’s planters have more built-in weight, but autosteer does provide one problem, because we no longer have markers on the planter that also added to the weight to keep it in the ground,” Jasa says.

Center-fill planters today often have plenty of weight at the center of the planter, but the outer edges can be too light and won’t plant as deep and uniform. You may have to add weights to the ends if that’s the case.  

2. Should I plant down the old row or in between the rows?  “We plant down the old rows,” Jasa says. “On the old rows is where there is the most biological activity.” If you can’t plant down the old row, get as close to the old rows as you can until you get the soil structure built up, he adds.  

3. How do I improve seed-to-soil contact? Jasa says that it isn’t uncommon to see planters going through the field with the hitch and front of the planter too low and the row units in the tail section too high, with the planter unlevel. This means that seeds are being planted too shallow, and you may lose the pinching action of the wheels, and the furrow won’t close over the seed properly.  

Make sure your planter seed furrow opening disks are sharp and working together, Jasa says. Over the years, Jasa has quit using other residue mover wheels on his planters. As the soil structure in his research fields has improved over the years from no-tilling and the addition of cover crops, he doesn’t need residue movers. “Even in ridge till, our best stands are planting no-till on top of the ridge with no residue movers,” he says.  

There are many different kinds of closing wheels available. Some producers may use two different types of wheels on the same row unit, one to firm the soil around the seed and the other to create some loosened soil.

“There are dozens of closing wheels to choose from,” Jasa says. “Ask yourself why they built that wheel, and what conditions were those wheels built for. Then look at your own conditions, and ask yourself if they are the same.”  

4. What do cover crops do for a no-till system? “If it’s being harvested by livestock above the ground, that is forage,” Jasa says. “If it is being harvested belowground by underground livestock, that’s a cover crop.” In his own research fields, Jasa is looking for more diversity.

“We’ve had huge increases in soil biology by getting cover crops into the system,” he says. “It surprises a lot of people, because everyone thinks you have to use tillage to get rid of heavy residue. Soil biology gets rid of the residue. The combination of no-till and cover crops steps up the soil biology so much that corn residue is just disappearing.”  

Jasa also advocates for getting a cereal grain such as wheat into the crop rotation to open up more cover crop options. Planting cover crops on wheat acres is convenient, because producers can plant into wheat stubble right after harvest and have a longer growing season than after corn or soybean harvest. 

Jasa plants a diverse mixture of cover crops in wheat stubble. “Volunteer wheat is controlled because Mother Nature doesn’t let wheat get going in a good stand of cover crops,” he says.  

Learn more about planter considerations for no-till and cover crop systems by emailing Jasa at [email protected].