I wonder if I could break ground with a pickaxe and broadfork a row very early this spring, and then mix in hot (wet) charcoal, follow with seed, and then pull a low tunnel over all in one go to get a nice long bed of interplanted commodity crops rolling way before last frost, like March instead of May here. Maybe drop jugs of warm water painted black every few feet along the way for thermal mass? Also any advice on charcoal retorts would be appreciated