I've done it a couple times before. We had a pipeline company clear overgrowth - mostly small trees and shrubs - out of a tree line that bordered one of our fields. If they do a good job and get those tree stumps totally flush with the soil surface, its really not that hard on the drill. If you're drilling grass or small seeded cover crops, you're really only pushing those seeds 1/4 deep or so. Also, the planting units on the drill ride on springs, so they'll roll over a stump pretty easily - especially if you take it nice and slow. The problem I ran into was the volume of mulch left behind. It was thick enough that it prevented the seeds from actually getting any contact with the soil. On the second attempt, I used a rake to drag all the mulch out into the field, so I could just plow it under. Once the mulch was gone, I actually got a pretty good stand of grass planted. As I mentioned before, you just gotta make sure the stumps are good and flush with soil level and take it extra slow.