Pigeon Peas -- can they inoculate themselves?

One important crop in the Caribbean system known as conuco is the pigeon pea, Cajanus cajan. According to Wikipedia, "Pigeon peas are both a food crop (dried peas, flour, or green vegetable peas) and a forage/cover crop. In combination with cereals, pigeon peas make a well-balanced meal and hence are favoured by nutritionists as an essential ingredient for balanced diets.... Pigeon peas are in some areas an important crop for green manure, providing up to 90 kg nitrogen per hectare. The woody stems of pigeon peas can also be used as firewood, fencing and thatch. It is an important ingredient of animal feed used in West Africa, especially in Nigeria, where it is also grown. Leaves, pods, seeds and the residues of seed processing are used to feed all kinds of livestock."

However, on soiltosupper.com, I find the statement that "To allow for [nitrogen fixation] and to use Pigeon Pea as a nitrogen improver, the seeds of this plant must have an inoculant present when sown. The inoculant contains the bacteria needed for the specific legume."

I find two difficulties with this. First, the inoculant I have seen for sale in the US is formulated for the common legumes of that country, i.e. peas and common beans. Secondly, I have not found any source of inoculant in the Dominican Repermies, where I am growing pigeon peas.

Now, considering the plethora of leguminous trees in the Dominican countryside -- including the most common living fence post tree, Gliricidia sepium (known as piñón) -- I believe it is quite likely that wild Rhizobium are already present in the area, but of course I lack the equipment to verify this. Is anyone aware of data as to whether leguminous trees in these systems can inoculate themselves, i.e. find symbiotic Rhizobium living wild? If not, what are some inoculation techniques in the absence of available commercial inoculants?

I will be following as I asked myself the same question and did not find an answer for my pigeon peas, that we call guandul here (say wandool !). Innoculant seem to be species specific/associated and I do not remember what group of bacteria is necessary for cajanus cajan. I also remember the informations that some legumes can go with "what there is" when they do not have the prefered bacteria. So for example here i can rely on tagasaste and bitumina bituminosa, called tedera, as potential sources.

I doubt my PPs have what is needed for them for a reason, if somebody can validate it or not.... They have a big production difference between rich garden soil and poor natural soil. I believe it should not be like this for a legume....

Something else that could be done for checking, but I have not, is to plant anyway, and uproot to have a look at the famous nodules on the roots....

As inoculant have to be put with the seed and are not supposed to be added later, the start seem difficult without having innoculant... I have also only found some abroad, and i don't know if this can travel without arriving dead! Anybody who knows?

Then, is it possible to take some legume roots from outside, and burry those roots near our plants? How do rhizobium travel alone in a place?

Hi Xisca,
we are also looking for inoculants for our pigeon peas and other legumes in La Palma. If we find any useful information we will let you know. Your project sounds really interesting. We are only just starting.
Catrina and Jane

Jason Hernandez wrote:I believe it is quite likely that wild Rhizobium are already present in the area, but of course I lack the equipment to verify this.

A digging stick and your eyes are all the equipment that you need. Plant the pigeon peas. Dig them up, and look at the roots. Do they have nitrogen fixing nodules? If yes, then there are suitable species of bacteria already present in your local ecosystem.

Catrina Liesch wrote:Hi Xisca,
we are also looking for inoculants for our pigeon peas and other legumes in La Palma. If we find any useful information we will let you know. Your project sounds really interesting. We are only just starting.
Catrina and Jane

Great, let's take contact! Amazing, people in La Palma!

Joseph Lofthouse wrote:

Jason Hernandez wrote:I believe it is quite likely that wild Rhizobium are already present in the area, but of course I lack the equipment to verify this.

A digging stick and your eyes are all the equipment that you need. Plant the pigeon peas. Dig them up, and look at the roots. Do they have nitrogen fixing nodules? If yes, then there are suitable species of bacteria already present in your local ecosystem.

Like those pics...
https://www.ecosia.org/images?q=pigeon+pea+nitrogen+fixing+nodules

It is not so easy... how long does it take to them to appear? I think it cannot be seen yet in a young plant, and was wondering how long it takes?
Even on our local wild legume called tedera and eaten by goats but not by humans, and so common, I cannot really see those profuse nodules as in internet photos! White acarians on roots, much more!

Pigeon peas and peanut need the same EL inoculant.
https://hancockseed.com/el-type-inoculant-6-oz-bag-21.html

So start making some peanut (root or inoculated seeds)  slurry to inoculate your Pigeon pea

The list is even much larger than peanuts! Thanks for the link! For example lima beans that I have, so I might check if they have nodules...

Yes other than soybean it is the same innoculant that pretty much all other edible "regular" legume uses.

Also the poorer the soil is the more nodules you will find to make your slurry. Check them before they go to seed.

how long does it take to them to appear? I think it cannot be seen yet in a young plant, and was wondering how long it takes?

I have always heard that nodules start appearing about the same time as the first flowers.