How to cost effectively remove large sandstone boulders from ground?

I have a farm in an area that has some large (mostly sandstone) "stones" (boulders that are 5 to 10 feet in diameter) in an area of the field that I need to turn into a farmable area. These are mostly under the ground and some of them are entirely under the ground and I only found them after starting to dig. This area is within about 1000 feet from a highway so dynamite isn't an option. Are there any creative methods for breaking up and removing boulders?

I take it you want a nice flat field? For machine agriculture?

Many farms that I have seen in the last few years that I started looking seem to actually leave a certain amount of "natural" growth amoung their fields. I'm not sure their rational, but it's common enough that I doubt it's just a wish to be virtuous and organic. Depending on the quantity, maybe these stones could anchor "natural areas" if you decide there's some sense to that.

Have you located all of the stones?

I guess you have priced out a large excavator and dump truck?


Regards,
Rufus

Yes, I would like to be able to till the ground and even mow without hitting rocks.

They are sporadic and there are too many to locate them with certainty.

I'm hoping that I can somehow manually "destroy" the stones, perhaps by some tricky mechanical method or perhaps a chemical method (other than super powerful explosives).

This thread has info on it.

Gerald, we use our tractor to lift the rocks and pry them out.  We don't have any other way to move them and our boulders are as big as your.

Our tractor has a front end loader.  Without that we would not be able to move the rocks.

Since we have no other way to move them we have to pile them at the border of the area we want to clear.

It really works as we have successfully moved about 10 rocks this way.

We wanted to clear the way into our tank (pond) in order for it to fill up with water, so we tried blasting which did not work.  This was before we got the tractor with the front end loader.

We live where it is really really rocky so I can feel your pain.

Glacial erratics are really common here, the largest one the family has moved took 2 200hp tractors and a buldozer to move it's around 3m long by 2m tall and a meter thick so it weighs a fair amount. it took out the plough when it was found :( The way they are moved here is with a tractor with forks up to around a ton in weight and from there it's chains and digging to pull them out. no one destroys them in situ.

If you have heavy frost you may be able to split some over winter to make them smaller and easier to move, but that's really going to depend on the rock, it's bedding and any faults already present.