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Missouri | Just curious how much compaction difference there is between tires vs. tracks on tractors? |
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South Central Illinois | Very little if the soil is fit to be worked. |
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East Central Ia | Can be significant IMO.
I was shocked putting on nh3 this spring in very dry conditions for our area. Was pulling a 17knife bar with my MT855 and the toolbar left deeper tracks then my tractor did in fall chiseled ground.
But the biggest advantage I think is the elimination of the pinch row compaction you get with duals. |
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Wi | JDIH Fan - 4/29/2014 19:52 Just curious how much compaction difference there is between tires vs. tracks on tractors?
Lots of factors that play into it. What compaction are you worried about? Surface? sub surface? What are your field conditions? What tires are you comparing to? |
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Woodham, Ontario | Properly inflated flotation tires will compact less, but you still drive over more area.
Tracks compact less than overinflated tires or row crop tires.
A quadtrac or rowtrac also weigh more than their wheeled cousins... |
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Ogallala,NE | i'd like to see the raw data on this one. i find it pretty hard to believe that even properly inflated 800's apply fewer PSI than 30/36" tracks. |
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Dayton, IA | You can probably get tires down to the same pressure as tracks with proper inflation, but not on the same width single tires, you have to use duals or wider singles. So you have the same pressure on twice as much ground. An 18 inch track will compact 1/2 the ground as 18 inch duals. Give or take a few psi, compacting 1/2 the ground should be a positive to the tracks. |
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Wi | mkurkowski - 4/29/2014 21:06 i'd like to see the raw data on this one. i find it pretty hard to believe that even properly inflated 800's apply fewer PSI than 30/36" tracks.
Theres a lot of data showing a lot of things. I've seen some where they showed in certain conditions tracks compacted far worse than many think due to pressure points and dwell time. It all really just depends on the situation.
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Wallis, TX | We demoed green and yellow back in the late 90's. When ballasted for using heavy 3 point mounted equipment, the front of the tracks were cutting a rut when the implement was down and the rear cut a deep rut when carrying the implement. If we were just draggin' a disk or field cultivator it would have been great, but for what we were doing we stayed with tires. Like most things, each situation/soil/usage is different. You can count on one hand the number of tracked tractors in row crop around me.
Edited by twraska 4/29/2014 22:47
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sw mn | www.extension.umn.edu/.../tires...and-compaction/index.html
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SWMN | you need lift assist so not to over load front with mounted equipment |
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Oregon | That link did not work. Do you have another one? It looks interesting. -Mike |
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Wallis, TX | Then I would have to drag the lift assist wheels over the beds on every turn. BTDT, a big pain. |
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South Western Ontario, Canada | BigDave - 4/30/2014 01:17
you need lift assist so not to over load front with mounted equipment
Not to mention the fact the lift assist will compact from extra weight and most are wheeled units.
I do understand your point but I see it as a catch 22. |
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West of Mpls MN about 50 miles on Hwy 12 | I remember this research very well. Here's a cut and paste from the link. More than 10 ton/axle is kind of a big deal no matter how you try carry it. Axle load is axle load.
http://www.extension.umn.edu/agriculture/Tillage/soil-compaction/in...
Tracks vs. tires
Tracks, as an alternative for tires, are not new in agriculture. Tracks accounted for 6-10% of all tractor sales between the years of 1925-1966. However, in recent years, the change from steel to rubber tracks, improved ride-ability, increased traction, and research citing that tracks create less surface compaction than tires have increased the popularity of tracks.
Combines and grain carts can create compaction as deep as 3 ft.
Tractors equipped with either tracks or tires can create surface compaction. The question is "Which one creates the least amount of compaction"? The answer: both radial tires and tracks will result in similar surface compaction if the radial tires are properly inflated.
Tractors weighing less than 10 tons an axle usually keep compaction in the top 6-8 inches, which can be alleviated by tillage. By and large, even the biggest tractors weigh less than 10 tons an axle. However, combines and grain carts weigh much more and whether equipped with tracks or tires, they can create compaction as deep as 3 feet.
In general, contact pressure largely determines the potential for compaction in the plow layer, while total axle load determines the potential for subsoil compaction. This is important when comparing tracks and tires for compaction effects and depth.
Tracks exert a ground pressure of approximately 5-8 psi depending on track width, length, and tractor weight. Radial tires exert a pressure of 1-2 pounds higher than their inflation pressure. For example, if a radial tire is inflated to 6 psi, the tire exerts a pressure of 7-8 psi on the soil. However, bias tires inflated to only 6-8 psi cannot operate efficiently and easily wear-out with such low tire pressures, consequently they have to be inflated to 20-25 psi.
Research has shown that tractors equipped with either tracks or radial tires create compaction in the top 5-8 inches, however, compaction effects were negligible below that depth. But what effect do tracks have on subsurface compaction when used in conjunction with heavy field equipment, such as grain carts or combines? Keep in mind that depth of compaction is a result of total axle weight and the role of ground contact pressure is secondary. Whether the equipment uses tracks or tires, the total axle load is nearly the same. Tracks will improve traction and ride-ability, but a 25-ton per axle grain cart will still create subsurface compaction.
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Wi | I thinK I saw one from Purdue that had a lot of the same data/info.
IIRC topsoil compaction (up to 12" depth IIRC) was a result of tire pressure exerted on the ground so you could reduce topsoil compaction with better flotation regardless of axle load. This compaction can also be easily removed. Subsonic compaction (over 20"depth IIRC) was a result of axle load only and no amount of flotation would change that. They also said that normal freeze thaw cycles did little to remove it. The space between those two was a combination of axle load and tire pressure.
Plow layers also played into the compaction issue. They acted as a barrier and reduced the amount of compaction that was able to get past them.
They showed tires inflated to 6psi compared to tracks both on 8000 series Deeres. Both were able to produce up to 18psi on the ground in certain spots. They said that even though the tracks contact patch is larger, it still has pressure points where the wheels are and soil dwell time is longer than with a tire which can lead to more compaction. I remember them saying generally the pressure exerted on the topsoil in a radial is 2psi higher than the inflation pressure. It's important to note though that the pressure from radials is much higher near the sidewalls versus Bias which carry the load in the center.
It's interesting data to say the least but like anything its really all in how you interpret it and apply it to your conditions. Obviously soil type and condition plays the biggest role and it's impossible for studies to test every variable. The real test is in your own fields and what you see. The main thing to take away from the research is how to test it equally and what to look at.
I tthink tires can compete with tracks however the issue is their size. They have a much wider footprint which can be an issue at times . If you are doing controlled traffic/tram lines you could argue that a track compacts much narrower area. The people getting the same flotation as tracks are often running dual 710s or dual 800s. That's 5' of tire on each side plus a foot or so between the duals so 6' or so versus 3' for the track.
If I had a lot of time money and a soil box I'd love to test it. But I don't. The research center for our university is down the road though. |
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Oregon | You can not compare the width of tire a tire contact patch to the width of a track contact patch without considering the length of each contact patch. Obviously the greater footprint due to length is where tracks make up the (typically) greeter contact area. -Mike |
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Wi | I'm not talking contact patch. I'm talking the percentage of the field subjected to the compaction. You don't drive over every inch of the field. Tracks effect a smaller overall area than tires that can provide the same low compaction. |
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| If you want to know what your ground pressure is go to the tire manufacturer and look up the Flat plate area for both your front and rear tires on a mfd multiply each flat plate by the number of tires then all you have to do is figure out your weight split on your tractor and divide out by for example a 40 60 weight split front to rear on a mfd (.4 * gross tractor weight)/Front tire flat plate = Front tire psi
(.6* gross tractor weight)/rear tire flat plate = rear tire psi
I have done many comparisons on the 4wd tracks vs wheels ground pressures and the only way to get a wheel machine close to a quadtrac is to put triples on it
that is even with a Case ih quad weighing more than its wheeled cousin.. moral of the story is you get a much bigger area for weight distribution
The other benefit is your are only running one set of tracks through the field on a track machine vs two with wheeled... |
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Compaction - Tires vs. Tracks
