Non-legume nitrogen fixing, Frankia

[shaneatwell]

I haven't seen a discussion here of the non-legume nitrogen fixers. Fascinating group.

Most of them form nodules with Frankia species actinobacteria (as opposed to the rhizobia that symbiose with the legumes).

Some fruiting examples:
Yangmei (Myrica rubra) and others in the Bayberry genus Myrica. Not only do some produce edible fruits, but many produce wax that was used to make candles.
Guomi (Elaeagnus multiflora), Hardy Silverberry (E. commutata) and others in the genus Elaeagnus (e.g. russian olive, E. augustifolia)

Some natives/ornamentals:
Alder, Alnus
Wax myrtles (Myrica californica, M. cerifera), used by some here as rootstocks for yangmei. Anyone tried M. hartwegii?
Ceanothus species
Mountain Mahoganies, Cercocarpus

Many of these nitrogen fixers are pioneer species in inhospitable conditions, which makes sense. Can be invasive.

I just planted goumi and hardy silverberry. Very different root systems. Guomi has a mass of multi branched thin roots. Did not notice any nodules. The Hardy silverberry on the other hand had 3 larger roots with few side branches and several obvious large nodules.

I see lots of posts on TFF regarding actinorhizal plants, but not much discussion of nodules, nitrogen fixing, inoculation, etc. E.g. Goumi (Eaeagnus multiflora), E. latifolia http://tropicalfruitforum.com/index.php?topic=558, E. pyroformis http://tropicalfruitforum.com/index.php?topic=4379

Anyone else fascinated by these guys?

[stuartdaly88]

This is an awesome topic. I never even imagined Goumi and Yangmei fixed nitrogen!

Something I read once that i think about is do nitrogen fixers use up all of their own nitrogen or is it really true that they leave some spare?
I grow bush bean in some of my fruit pots without ill effect but I do mulch the leaves etc back into the pot.

Would be cool to do an experiment like growing annuals at the foot of a Yangmei and a non nitrogen fixer and weighing the total mass of the annuals at the end of the season to compare.

[shaneatwell]

I believe they use it up and have to drop leaves or get pruned somehow to make the nitrogen available to other plants.

[Pancrazio]

Douglas fir also fixes nitrogen in its leaves.

[Luisport]

Hi! I think Sea Buckthorn or Seaberry ('Hippophae Rhamnoides') is a fixing nitrogen plant too... and have an impressive medicinal and nutrition profile. https://en.wikipedia.org/wiki/Hippophae_rhamnoides  http://www.pfaf.org/user/plant.aspx?LatinName=Hippophae+rhamnoides 

[Doglips]

Most, if not all nitrogen fixers release the goods after they die and roots breakdown.  I wouldn't imagine that a tree would be good choice due to a slow return on investment.  Annuals would be the way to go, if this is your focus.

[shaneatwell]

Or regularly cutting off/down large portions of the tree.