I'm not a subscriber to Mirai live and I've wonderd for a while now how/when he deals with the field soil at the center of the root ball beneath the trunk. At some point in the video, Ryan alludes to the fact that his approach departs from what he learned in Japan; I find that very interesting. I also wonder if there's kind of a standard method among Japanese professionals dealing with field soil in the "shin". Maybe they all use something like Boon's method. Do any of you subscribers know how Ryan's method differs from Kimura's?