Nitrogen fixation: honey locust

I know that Honey Locust doesn't t form root nodules. But is it a nitrogen fixer?

Hi Pavlo, Welcome to Permies!

I don't have much experience with Honey Locust but here is a thread you might find useful.

https://permies.com/t/36615/Honey-Locust-nitrogen-fixing

Hey Pavlo,

This question is much more difficult than I originally thought! Here's what struck me from the current page on Wikipedia:

The ability of Gleditsia to fix nitrogen is disputed. Many scientific sources state that Gleditsia does not fix nitrogen.
...
How this happens is not yet well understood but there have been some observations of nitrogenase activity in non-nodulating leguminous plants, including honey locust.
...
It is not known whether the non-nodulating nitrogen fixation, if it exists, benefits neighboring plants as is said to be the case with nodulating legumes.

https://en.wikipedia.org/wiki/Honey_locust#Nitrogen_fixation

Sorry I don't have an answer, I just find it very interesting that there is dispute as to whether some legumes fix nitrogen. I never knew that.

I do want to share, however, that there is a sibling to Honey Locust, "Black Locust" which apparently does fix nitrogen. I hear Black Locust can be quite aggressive. However since it's native to my region (southeastern US), I intend to grow it.

Josh Terrell, what about Clammy Locust?

Pavlo Khylynskyi wrote:Josh Terrell, what about Clammy Locust?

So pretty! I hadn't heard of it, but I added it to my list now. Will grow that one too since it's native 😀

As for whether it fixes nitrogen, I don't know, and it does not seem to be as well documented online, but I bet the answer is out there somewhere!

Josh Terrell wrote:As for whether it fixes nitrogen, I don't know, and it does not seem to be as well documented online, but I bet the answer is out there somewhere!

INTEGRATED APPROACH TO NITROGEN FIXING TREE ... https://pdf.usaid.gov/pdf_docs/PNAAS616.pdf

A botanist permie friend said honey locust has recently been proven to fixate Nitrogen without root nodules, as has long been the belief and observation of ranchers and farmers in its native region. I do not have the journal reference she got it from. I trust her though on questions like this.

Matt Powers has also been collecting research, much of it originating from Dr James White, on how most plants can essentially fixate nitrogen through hyper-oxidation of nitrogen rich bacteria in their root hairs. Any plant with trichomes (hairs) also fixate nitrogen with endophytic bacteria located in the above ground trichome/hair.

In addition, many plants we do not consider carnivorous (like tomatoes) also acquire a significant portion of their nitrogen through the insects that die amidst those sticky hairs and decompose on the plant. It seems to me nitrogen is much more easily available to plants living in diverse, regenerative soil than was ever suspected by researchers of chem-ag based degenerative systems. I also think that any plant that attracts birds and insects in large numbers also effectively acquires nitrogen and other nutrients from their manure. Mulberries and himalayan blackberries would be examples of this, and honey locust probably gets this benefit as well from those animals attracted to its energy rich pods.  

Pavlo Khylynskyi wrote:I know that Honey Locust doesn't t form root nodules. But is it a nitrogen fixer?

Hello there! I was wondering if you are looking for any N fixing trees or what type of restrictions you are looking work around? Zone, soil, waters, ect?

There are other N fixing trees but I assume you want to use Honey Locust for a certain reason. Can you tell us what your criteria are?

Demitrios Pitas wrote:Can you tell us what your criteria are?

I'm looking for a nitrogen fixer for my chestnut-walnut food forest in zone 6.

So I wasn't able to come up with a lot. Catalpa, Kentucky Coffee tree, Honey locust are probably the major ones there are.
There are undoubtedly more but they would be obscure and hard to get.
The reason you won't find much is because Walnut usually grows in mature soils. I know they can grow in sandy soils but it isn't common.
With that in mind, there aren't that many trees that fit the category because N fixers are adapted to poor soils that can't support Blk Walnuts. As a result, they never developed tolerance to juglone. I know thornless Honey Locust will grow. I have a family farm with this exact combination in zone 5.
Hope this helps.
good growing