Polyculture Pattern Language: Nitrogen Fixation Patterns

Eric Toensmeier has just written a superb article on patterns of nitrogen fixation.

Here's a snippet...

When Dave Jacke and I were writing Edible Forest Gardens, we discussed polyculture design extensively. We felt that we were beginning to see the vague outlines of an international pattern language of polycultures – a set of basic templates that might be used regardless of climate or the particular species in question.

Given the huge diversity of crop species and possible combinations, there may be an almost infinite number of polycultures grown in the world today. In my garden I grow many, and I’ve been fortunate to be able to travel and see many more. Reading and research have introduced me to a great number including commercial systems from around the world.

That pattern language is beginning to seem clearer to me. For example, though agroforestry systems including food forests are practiced around the world and in many climates, I only see a few basic patterns representing the majority of the use of nitrogen fixers.

The rest of the article can be read here

These were the list of patterns that Toby came up with:
1: The nitrogen-fixing canopy
2: Nitrogen-fixing understory
3: Early-succession nitrogen-fixers
4: Irregularly intercropped nitrogen-fixers
5: Alternating rows of nitrogen-fixers
6: The nitrogen-fixing living trellis
7: Nitrogen fixers in pasture mix

I guess in the tree field my style is sort of #4 with lots of alder, although I also rely on native legumes herbs like clover and vetch spreading around (Not as uniform as the example he gives at #2) That's not really a food production area though. I do forage a bit (and hoping for hazel nuts this year)

I guess I haven't planned the nitrogen fixing but just expected that with a good variety of plants it would happen naturally. What about everyone else? Do you-all plan your nitrogen fixers or just add a good mix in and hope that it all works out in the end?