Adam, sounds fun. There’s no economic way to spread compost or biochar over 500 acres, that said you can still do “permaculture on 500 acres. First look into keyline design, it’s a bit complex but there are people out there who can map your keyline and it’ll pay off in the long run Basically it’s a water harvesting strategy that is mindful of your equipment needs. Second consider alley cropping. Basically having rows of trees maybe Almond.. planed along the keylines then you have the hemp in the alleys. The USDA has lots of studies going way back showing that alley cropping actually increases crop yields, due to the many benefits trees offer. Third look into pasture cropping, the only economic way to regeneratively spread nutrients is with grazing animals. Maybe if you planted the whole acreage in white clover a cool season perennial you’d be able to lease the land for grazing when the hemp is out, then graze it low before planting and plant with a no till seeder or transplanter into the stubble. Ideally the grazer would utilize high density rotations to maximize grazing/ manure distribution.