It slows down dramatically after the initial stone purge right? I have some land where there are piles of large stones in the grove bordering old cropland but

It slows down dramatically after the initial stone purge right? I have some land where there are piles of large stones in the grove bordering old cropland but there are no visible stones in the field. I imagine 1 stone pushes through on the 80 acres every few years no need to add humus.