I have Amish farmers close to my area. I have never seen any of them trying to pull a chisel plow and I doubt that horses could pull more than on or possibly two chisels. Would take forever to do a field at that rate so I really doubt they use chisel plows. They do however plow their fields with a plow so I doubt it is the plow that causes hardpan. Hard pan was not a problem 50 - 60 years ago when equipment was small. When the tractors started to get larger after the war is when the hard pan became a problem so it is the weight and not the method that causes hardpan.
Edited by chieffan, April 18, 2015 - 07:37 AM.