As I understand it, just about any legume (pea/bean family) will fix nitrogen (actually it is their mycorrhizal fungi associated with their roots that does the work!). (There are nitrogen-fixers that are not legumes, as well.)

There is a VERY long list of legumes that are native to North American prairies, but you will have to do a little research to find out what is native to your area. Some widespread prairie legumes are:

Wild indigos (Baptisia)
Leadplant and false indigos (Amorpha)
Bush clovers (Lespedeza)
Prairie clovers (Petalostemum/Dalea)
Sensitive pea, partridge pea (Cassia/Chaemacrista)
Sennas (Senna)
Lupines (Lupinus)

I have most of these species in my prairie garden -- not because they fix nitrogen, but because the are beautiful and diverse members of prairie communities!

i thought its a bacterium that fix's the nitrogen.

froggy

Froggy is right:

Mycorrhizae are fungi that help ALL vascular plants (not just legumes) take up minerals, especially phosphate, from the soil.

The somewhat similar-sounding Rhizobium bacteria are found in nodules in the roots of legume-family plants, where they capture atmospheric Nitrogen dissolved in soil moisture, then convert it to usable form for the plant.

In addition to the nice list of legumes mentioned above that would work in your setting, several other plant families have species which can fix nitrogen, including the alders (not a good plant for your sandy area) and New Jersey tea (Ceanothus americanus) which is a highly desirable prairie plant.

Thanks for the list and the info on the fungi :)
Are there any other plants who's roots run as deep as the Purple Prairie Clover that I don't want to plant?
Vera

Wow. I can't imagin how many times I have seen the terms mycorrhizae and Rhizobium without making a mental distinction between the two! Learn something every day.

Doctorant...can u think of any other spp. or family that fix nitrogen? and im assuming that its the same type of nodules? and Rhizobium's?

i knew that NJ tea fixed N but i guess never thought that its not a legume. also maybe some ref. on this topic would be nice.

froggy

Don't know if it's roots are a threat to your water pipes, but those of Baptisia sp. can run as deep as 40 ft. Most prairie plants have deep roots so that fire can't reach them.

NJ tea isn't in the legume family. It's in Rhamnaceae...isn't that the buckthorn family?

Thanks lycopus....
Guess NJ Tea wouldn't be native to ND...I'll stay away from the Baptisia family too :)

It isn't native to ND, but Inland Jersey Tea (Ceanothus herbaceus) is.

The general biology textbooks all claim that nitrogen is "fixed" (chemically bonded to other atoms or ions, and thereby available for use by organisms) only by nitrogen-fixing bacteria in Legumes and by lightning. Both of these do, indeed, fix nitrogen. Both are important fixed-nitrogen sources.

But the fact is that neither produces enough fixed-N to account for all the nitrogen in the proteins and nucleic acids (and other chemicals) in the plants of prairies (and other ecosystems). The missing nitrogen-fixers are blue-green algae growing in soils and dead stems and leaves (duff). Blue-green algae are major sources, and they are promoted by simply having a prairie grow well. The dead roots, leaves, and stems (biomass) provides substrate and nutrients for the blue-greens. Sunlight provides the energy.

The textbooks are incomplete.

hi,
no one seems to have addressed the issue of deep-rooted plants tapping the water pipe. that water pipe ought to be leakproof, i.e., not releasing water into the ground. if it does leak, the prairie plants will help themselves. otherwise, there is no problem in this scenario.
way to grow,
mrnatural

Oh Thank You mrnatural!
I was about to pipe up again....no worries here now :)

John Blakeman: Thanks for the point about free-living (non-Rhizobium) N-fixing bacteria. They are indeed the most important nitrogen fixers, easy to forget because they are largely invisible. Indeed, many others beside the cyanobacteria are involved, also.

Froggy: The non-legume nitrogen-fixing plants have bacteria other than Rhizobium. I don't remember details -- a good account would require a careful review of botanical literature.

Thanks again for the great information. Does anyone know of a web site that would give more details on this topic?

You could try a browser search on a term such as "nitrogen fixation". The link below is a quick one I did. You could change the details of the search in various ways to narrow the search.

Here is a link that might be useful: N-fixation

-Dorothy Hinshaw Patent, in the book "Bacteria," describes
a second group of nitrogen fixing bacteria. These are
named Actinomycetes, and they form root nodules in trees
and shrubs found in temperate climates. She states that
alders contribute nitrogen to the soil by dropping their
leaves in the fall, "while they are still green and rich in
nitrogen."

You could also plant northern bayberry (Myrica), bristly locust(Robinia) and sweetfern (Comptonia) shrubs. These all harbor nitrogen-fixing nodules, are zone 4 hardy, and are suitable for poor, dry soils. The bristly locusts have a tendency to spread rapidly, though.

A good but difficult text is "Nitrogen Fixing Organisms" (1990) by Sprent. I got a copy via inter-library loan. The Sprents (there are two of them) agree with some of the conbtributors to this thread that only bacteria are involved. But they do make the point that mycorrhizae improve the efficiency of nitrogen fixers, and vice versa, so that their joint efforts produce more nitrogen than the sum of the two working independently. Regards, Peter.

Hi Vera. Lead plant and showy partridge pea grow in the roadsides in our area, so you know they'll survive! I have some planted last fall, so this year I can tell you more as things develop. The roots do indeed go very deep, but they are thready and delicate, so as to harvest all the soil moisture needed. They are not like tree roots! I doubt those thready roots can get into a water pipe, but I'm no expert.
Have you decided already? Hope your planning is going well. I know you're not planting yet, ha ha. - raptorrrunner

lead plant is one of my favorite plants, does anyone know if it is possible to propagate from stem cuttings?

Oxytropis, Astragalus, and Vicia species are commonly found on native prairie just to the north of you in SK. Was hiking on prairie south of Estevan just this past weekend and species of each were in bloom.

Apologies to Nick in advance for my stridency, but ...
Avoid Robinia like the invasive plague that it is!!! Compptonia and Myrica will not be happy in your location, but at least they won't be invasive. The suggestions for native herbaceous plants are much more appropriate for you site. And don't worry about those pipes; Fast-growing, thirsty trees such as silver maple and willows (and alders)are good at invading leaky pipes, but I've never heard of a prairie plant doing so.