We've probably had too much information on this now except:
What do you mean by this? Do you mean ploughing downhill? Do you mean slash and burning of forests? Otherwise, I can't see how you can say it was 'intensively' farmed. They grew the same crops continuously on the same land until they wouldn't grow there any more. There was no crop rotation, no fertilisation except by the free ranging animals, no enclosures, no weedkillers and large areas left fallow.