But upland areas have a fundamental problem, you are fighting gravity. He planted trees in upland areas, left a perrenial cover on the ground, he could plant native vegetables into it by cutting it back, leaving it alive, roots still untouched, just give the seeds a chance to germinate and grow. But the vegetables he grew this way will simply not do that everywhere. The vegetables that grow here with that sort of technique are not things you find in a marketplace. I see it ignored.
People say, no problem, and they get dependent on mining energy and nutrients from somewhere else.
They insist they will grow what they want, not listen to what the land and climate say. I can hardly state strongly enough my wariness about examples such as the farm you gave. I feel as if I have been shown a snapshot of someone who claims to be levitating, and I cannot accept it. I immediately suspect a trick. My experience is much too strong.