5 Planter Adjustments to Achieve Uniform Seeding Depth

Paul Jasa has been hearing complaints from farmers running front-fold planters with central seed hoppers. They are noticing problems with uniform seeding depth across the width of the planter. “Some of these planters even have automatic down pressure control systems that are supposed to ensure the planter has enough down pressure on each row unit to properly place the seed at the set seeding depth,” the University of Nebraska engineer says. 

Jasa found that the center section of the planter was performing as it was set by the farmers. However, shallower seeding depths were occurring on the wings. This is “especially a problem on planters without markers,” he adds.

Wings often need weight

The issue is a lack of weight on planters’ wings. “Many front-fold planters have more than enough weight on the center section with the central seed hopper and often large fertilizer tanks on the hitch,” he notes. “The down pressure system (even the manual adjust springs or air bag systems) may claim 400 or more pounds per row available down pressure. However, they may not be providing that on outside rows unless weights have been added to the ends of the planter.”

Toolbar design allows wings to float so the planter can follow ground contours. As such, the weight on the center section isn’t available for transferring to the row units on the wings. The exceptions to this, Jasa notes, are a few models from Kinze that have a weight transfer system and some aftermarket transfer systems. Even they may need additional weight.

To correct seed-depth inconsistencies, check down pressure and seeding depth when the planter is empty. At that time, check seed depth on all rows across the width of the planter. Down pressure systems on the row units on the wings near the pivot points of the toolbar will be able to transfer some of the center section weight to the row unit, Jasa says.

However, several hundred pounds of weight usually have to be added to the outside ends of the wings on these large front-fold planters for their down pressure systems to work properly. This is particularly true with planters lacking markers.

5 adjustment 
recommendations

Jasa offers these five planter adjustment recommendations. 

1. Level the planter in the field. When doing this, make sure the toolbar is at the proper height and leveled front to rear, perhaps even slightly tail down. This allows for the full range of movement of the parallel links and helps keep the planter on the row, which aids in seed-to-soil contact. 
2. Make sure the planter carrying wheels are exactly centered between the rows. Also, check that the wheels are carrying some weight while setting the toolbar height. 
3. Once the planter is level, try blind-planting with no seed in the boxes or other products on the planter. Stop with the planting units in the ground and check to see if the depth gauge wheels are in firm contact with the soil surface. If they are not, increase down pressure and try planting again. If you cannot tighten the springs, you may have to add extra springs or add weight directly to the row unit. If you cannot turn the depth gauge wheels slightly (especially on wetter soils), you may have to reduce the down pressure.
4. Check to see if you can slip the seeding mechanism drive wheels, as the down pressure springs or air bags will be lifting the toolbar. You may have to add weight to the planter frame for the springs or air bags to work against and to keep the drive wheels firmly on the ground to reduce slip. Don’t let up on down pressure springs to get the drive wheels back in contact with the soil because penetration to seeding depth is necessary.
5. Place a small amount of seed into a couple of seed boxes and plant a short distance. Check seeding depth, seed-to-soil contact, depth uniformity, and spacing uniformity.