An interesting video by the NRCS about soil movement through different soil types and structures. Yes - I know they show a picture of "Big Ag" but I've found that lately the Soils folks are waking up to more "permaculture" type methods. In fact geoff lawton stated that the USDA contacted him about teaching a PDC for them!
Subtropical desert (Köppen: BWh)
Elevation: 1090 ft Annual rainfall: 7"