Thats the type thing that they pull with D7 or so for forestry site prep, just like it says. Jesup is comfortably seated in the countries "wood basket". When we have site prep done around here the guy shows up with a D8 crawler and we have him bed it up. The attachment he uses be hind the tractor is a subsoiler upfront that is about 5 feet tall then a disk on each side thats around 4 ft in diameter. One disk turns dirt from the center the other throws it back into the center. End result is a raised be of about 12-18" depending on setting i guess that is subsoiled down about 4-5 feet to allow new seedlins to penetrate the hardpan, that is plowed allong the countours.
Its pretty impressive to watch, site prep is usually done after a summer of sitting fallow, so stumps have had some time to rot, but where talking some stumps easily 24" in diameter, that sub soiler will easily bust them in 2, splitting them like a giant knife, often times pulling half of it out of the ground. I will try and dig some pics up of it in action.