Suggestions on clearing a field

[Matt G]

I have about 3/4 of an acre fenced off on the back of my property that has OVERGROWN to say the least. Before fencing it off I hauled about 20 loads of dirt back there just incase I would need it. Now I would like to clear that section out and spread the dirt in my pasture and possibly move in some sheep. My problem is the grass is almost taller than my house so I don't want to put the tractor in there. I cant burn it because a pipeline runs diagonally across the piece, although that's a quick way to get the pond I always wanted if it blows!!. Is there any good sprays out there I can buy to kill it or is there anybody on here that has a license that can get some "good stuff" to take care of my problem? I'm open to any creative ideas.