With the potential for wet soils in some areas of the country this spring, compaction may be an issue during planting. Sidewall compaction in wet soils can be a problem, especially if the crop is "mudded-in" and a dry spell occurs after planting.
A majority of sidewall compaction occurs on wet soils when the press wheels/closing wheels of the planter are set with too much down pressure. This results in over packing the seeds into the soil.
Planting corn to a depth of 1 ¾ to 2 inches is optimum for nodal root development. This depth also allows for the press wheels to create good seed-to-soil contact around the seed. When properly closing the seed-vee, the sidewalls of the furrow should be fractured as the soil closes around the seed, eliminating the sidewalls and providing good seed-to-soil contact.
Spoked closing wheels till in the sidewall around the seed, providing loose soil for the seed-vee after the seed is placed in the furrow. Be careful not to have too much down-pressure set on spoked closing wheels as they may till the seeds out of the seed-vee. To reduce the aggressiveness of the tillage and to provide some soil firming and depth control, some growers will run one spoked closing wheel and one standard wheel.
More information related to planter down pressure in wet conditions is available on the DuPont Pioneer website.