By: Dewey Mann, Research Associate
As the ground temperature begins to warm up, preparations for spring planting are well underway. By the time this article goes to press, many farming operations will have already completed maintenance checks on spring planting equipment; meters calibrated, bearings and chains (if equipped) lubricated, planter unit leveled, change oil in the planter tractor, etc. Typically, ‘tire inflation pressure’ only makes the maintenance checklist if the operator has a planter with a ground drive system*. Sure, we might ‘check’ the tire pressure on the planting tractor, but where does our target inflation number come from? Possibly an inflation pressure we have used for years (25PSI), or a number we have heard thrown around the coffee shop. Proper tire inflation pressure can increase productivity, fuel efficiency, and yes, even ride comfort.
Common means of suspension on agricultural tractors include (from operator to the ground): seat, cab, axle, and tire suspension. Aside from upgrading to a newer model tractor, the quickest method for influencing ride comfort is to adjust tire inflation pressure (tire suspension). Consulting tire load and inflation tables, from the tire manufacturer, is likely the best source for determining the proper tire inflation pressure.
A row crop tractor equipped with 480/80R42 duals (4 tires across the rear axle), and an axle weight of 16,000lbs (4,000lbs per tire), the proper tire inflation pressure would be 12PSI (pounds per square inch).
The same concepts also apply for utility or lawn and garden tractors. If a lawn and garden tractor had a rear axle load of 1200lbs (600lbs per tire), and was equipped with 21x8.00-10 NHS tires, the recommended inflation pressure would be 10PSI.
ALWAYS consult the tire load and inflation pressure tables, and communicate with your local tire dealer to ensure the proper inflation pressures are being used; and they the tire manufacturer will guarantee the warranty at the selected inflation pressure.
*For those not familiar with planting equipment, a ground drive planter transfers power from a ground wheel, through a drive shaft to the planter transmission; if the diameter of the ground drive tire is altered (inflation pressure too high or too low), the planter rate will also be altered (underseeding, or overseeding). Modern planting systems are utilizing hydraulic or electric powered drive systems.
Example load and inflation scenarios referenced using: http://www.firestoneag.com/en/tire-info/load-inflation-tables/default.aspx
Dewey Mann, research associate for agricultural safety and health, and lecturer for agricultural systems management, can be reached at (614) 292-1952 or email@example.com.