Flotation and compaction are not the same. While it’s true that tracks “float” better than tires, they don’t necessarily offer lower soil compaction levels when compared to tires. With advancements in radial tire technology, tires may become the preferred choice over tracks.
Here in the upper Midwest we’re staring down another potentially wet spring as we deal with moving (and moving, and moving) mounds of snow around our yards. Although the wintry landscape may not inspire visions of dust clouds rising behind the planter, the reality is that field work is just around the corner. And you never know just what you’re going to face out there. One debate that seems to circulate this time every year is the tires versus tracks question. Which is better? As with any equipment decision, a lot depends on your farm’s unique needs. And a lot depends on recent developments in ag tire technology.
Tracks: The choice for getting it done (at all costs).
There’s no question that tracks can help a machine float through stubbornly wet fields. As tires rotate, they create a wave of soil in front of the tire in wet conditions. As the tire turns, it’s constantly “climbing” out of the rut. On the other hand, a track system’s lugs are “planted” in the soil and push the tractor forward. That means no ruts and, generally, better traction in wet soils when compared to standard farm radials. When farmers list their reasons for running tracks, wet soil traction is usually number one. After all, there are times, such as fall harvest, when you need to get in the field at all costs. Plus, track tractors give you a maneuverability edge: they are often narrower overall than dual setups, which may reduce white-knuckle moments when traveling narrow township roads.
However, tracks come with some notable drawbacks. The first is weight. A quad-track tractor is usually 20–30% heavier out of the gate. Tracks also have a greater rolling resistance than tires. That means more horses are devoted to pulling the tractor itself, which means fewer ponies are available for the real job of pulling the implement. More weight and more rolling resistance can mean more fuel consumption too. Field testing of John Deere 9620R and 9620RX tractors showed the wheeled tractor consuming approximately 15 percent less fuel than the track tractor. And with a host of moving parts—idlers, bogies, and other suspension components—a track tractor may give you sticker shock if several of the components (other than the tracks) need replacing at the same time.
Flotation and compaction are not the same.
While it’s true that tracks “float” better than tires, they don’t necessarily offer lower soil compaction levels when compared to tires. Why not? Because tracks concentrate the tractor’s load on the area of the track beneath the idlers and bogies. In other words, the tractor’s weight is not evenly distributed across the surface of the tracks. A Tekscan™ measuring more than 100,000 data points recorded the 9620R wheel tractor having a 16 percent lower average pressure and a 38 percent lower maximum pressure than the 9620RX track tractor.
The image and chart above show the high pressure points under each midroller. A study conducted by the University of Minnesota found that properly inflated duals will cause less compaction than tracks. Because tires are essentially rolling air chambers, they distribute an implement’s load evenly across their surface area.
As you’ll notice in the above chart, air pressure is vital to maintaining a tire’s compaction edge over its track competition. Outfitting a heavy tractor with tires that can run on lower air pressures (and adjusting your tire pressure for specific applications) will help prevent yield-killing compaction. In the study above, 6 and 7 PSI (front and rear respectively) was the optimal tire pressure for the 710/70R38 duals. The "over inflated duals" were set to 24 PSI.
Think about your operation for a moment. Are you inflating your tires close to 6 or 7 PSI for working in the field? Probably not. This is because 6 or 7 PSI does not allow for high-speed road travel. You may need close to 20 PSI to accommodate the higher speeds you drive from field to field. Unless you maintain slow travel speeds, you would likely need a central tire inflation system on your tractor to operate at 6 and 7 PSI in the field. (Remember, the correct air pressure depends on equipment weight, speed of travel, and application. We do not recommend going out to your shop and dropping the air pressure down to 7 PSI on all your equipment.) However, with advancements in radial tire technologies, operating at substantially lower air pressure—up to 40% lower—in the field while permitting high-speed road travel is now possible.
The best tires for cutting compaction.
In addition to the massive LSW super singles, meant to take the place of traditional dual setups, tire manufacturers have also introduced increased flex (IF) and very high flex (VF) tires in recent years. Increased Flex (IF) tires can carry 20 percent more load at a standard radial’s inflation pressure. Or they can carry the same load (as a standard radial) at 20 percent less inflation pressure. Very High Flex (VF) tires can carry 40 percent more load at a standard radial’s inflation pressure—or the same load (as a standard tire) at 40 percent less pressure.
In 2018, NTS Tire Supply studied the compaction effects of planting with LSW super singles in two different setups, giving farmers more options for reducing soil compaction.
We know that every farm is unique, which is why NTS Tire Supply is ready to help you find the best solution for your operation. We sell and service both track systems and the latest tire technologies from across the ag marketplace. Give us a call or drop us a line today if you want to optimize your traction in 2019.