Slippage of press wheel drives may occur more often than with carrying or gauge wheels because they operate in soil loosened by the seed furrow opener. While additional weight or down-pressure springs can reduce press wheel slippage, too much weight on the press wheel can cause excessive soil compaction around the seed, resulting in poor emergence. Soil conditions are a factor influencing slippage of carrying wheel, gauge wheel and coulter drives. Loose or tilled soil conditions increase the potential for slip, especially on coulter drives. On planters with carrying and gauge wheel drives, additional weight can help reduce slippage.
Tire pressure is important in carrying and gauge wheel drives.
Tires inflated to the recommended level tend to make planting more accurate. An under-inflated tire has a smaller circumference, causing more rotations at a given ground speed. This causes the metering mechanism to drop more seeds, and overplant. Although the operator's manual serves as a guide for setting the planter, make your final adjustments in the field to account for varying soil conditions. Two major adjustments are planting depth and seeding rate.