legumes for soil building

I posted this message on the legume site but figured no one would see it, so I am adding it here since it relates more to sustainable methods than to a discussion of veggies.

Legumes are used in "developing" countries for soil building, another forum I can't find. They are nature's way of capturing nitrogen and adding humus to poor soil. Direct drilling of inoculated legumes into permanent groundcover is part of a method of creating, not just inproving, but actually CREATING topsoil on degraded land.
Green manure, Keyline practices, carbon sequestering, crop pasturing--anyone doing this or interested in these ideas?