need some compaction data

Caught some kids driving through very muddy cornfields this summer. they are contesting that there is any damage other than to the standing crop. Do you guys know of any data of fact sheets showing the affects of excessive compaction? It sounds like these guys have been doing this to a lot of fields and the courthouse is happy to catch them (so am I!) Any help or good websites will be appreciated. Thank you.

Try this site. More about trees, but it still has some charts on it.
Untitled URL Link

Back a few years ago a buddy of mine was a blockman for DMI and he had some stuff on compaction , now i do not know for sure where it came from but i do know that it is out there . Maybe ya can get it from Ohio state or Purdue or one of the other collages that are big into Ag.

Just go out there with a probe of some sort and poke around. Shove it down in their wheel tracks and then maybe three feet away from the track. It won't give you any scientific data to take to court but you might have a little feel for it. I'm sure someplace like the extension office might have a probe with a pressure measuring device on it.

I've done probing for tile and it's surprising how much difference a wheel track makes in the amount of force it takes to push that rod in the ground. Jim

Seems that the question would be, will your normal tillage for next year's crop "cure" the compaction issue? Courts are very big on calculating actual monetary damages, not just liability. "No harm, no foul".

I don't know if this is quite the answer you are looking for but here it goes anyway.

So you say they were driving around in "wet" cornfields. How "wet" were these fields because soil compaction is a product of both the amount of energy put into compacting the soil and the moisture content of that soil. There is an optimum point that can be achieved, which on inorganic fine-grained soils is usually 10-12% moisture, at this optimum moisture content it requires the least amount of energy to get maximum compaction. Lower than that point there isn't enough water to provide lubrication and surface tension reduction to allow the particles to slide past each other, therefore to get to the maximum unit weight more energy has to be put into the soil. Higher than that point the air voids in the soil start to be reduced because they are filled with water and if you have ever tried to compact water it just doesn't work, unless you put enough energy into the soil to squeeze the water out of the voids.

Now how far down did this compact your soil? Well, depends on how many times they drove across a certain area. This is why plate compactors and rollers vibrate, to increase the number of loadings per pass to get the maximum penetration and energy input to the soil. But with a truck you don't get near the number of loadings, even if they crossed it 10 times the loadings are slow enough that the soil will tend to bridge and spread the weight out over a wider path as the depth increases. If they were using something heavy like a one ton with pizza cutter road tires they could probably penetrate 6-8 inches below the bottom of their tire track. If they had wider mud tires, maybe 4-6 inches. If the conditions were right.

So if you conventional till, or use any type of deep tillage it should penetrate deep enough to get though where they drove and compacted it. If you no till then this will definitely hurt your yield. As far as the plant parts go, I am clueless on that. I just know dirt.

One more thing you might want to take into account, depending on how far they dug into the ground is messing with your nutrient layers in your soil profile.Something else to think about to nail them with. Plus if it was a wet hole before because of the soil displacement and the soil they drove off with on and under their trucks it will be an even wetter hole now, which can lead to yield loss, workability issues etc. If you no till, this compaction could also cause water to not get to your tile if the field is tiled and your back to water issues.

Hope this helps.

thank you for your data!! I will be meeting with the courthouse today!