On a DB60 and many other planters there can be an enormous difference in the planter row unit downforce required on the center section row units running between heavy tire loads and the rows on the outside running in undisturbed soil.

One approach on a single section adjustable DP setup is to add 2 standard DP springs to the parallel linkage on those row units between or next to a tire. This avoids having to apply excess DP to the outer units just to keep the tougher units in the ground.

Even in no till I don't like to see the "margin" set that high. Especially with an airbag system that does not respond as quickly to changes as an hydraulic system, if you hit a wet, soft spot or worked headlands etc, 125 lb will just bury some outer row units and result in stand damage.

Jim at Dawn