I'm looking ahead to spring peas, and I want to treat the seeds with the rhizo innoculant. Looks straightforward. But any packet of innoculant I can find appears to be quite a bit more than what I would use for a relatively small garden. How long does the innoculant last? More than one season I hope? How to store it to keep it from expiring? Air dry it? Freeze it?
Instructions for N-Dure (one brand of rhizo innoculant) say it has just a one-season shelf life, but I'm wondering how firm that is. I'll be using it on seeds I've stored carefully that will be well beyond their expiration date, and I'm sure they'll sprout just fine.
Thanks. I guess my question is how do you know it's still working in year 2? I believe that the sign that peas are producing a lot of soil nitrogen is the nodules that form on the roots. If you get a lot of those nodules in year 1 of a bag of innoculant, and not many in year 2 of using the same bag, that would be pretty meaningful.
The inoculent I got had an expiration date and a guide. It said that the packet contained living organisms, and had to be kept cool. I had mine in the refrigerator. It also said it was only good for the year. Cowpea inoculent works on most peas and beans, but work best with specific varieties.
Some inoculents need to be activated by mixing the inoculent with a sticker (mine called for molasses) and the seed, then drying the seed in the shade. It had to be planted within four hours of the activation. Others are designed to just shake around the seed in the planting hole.
Inoculent is not necessary if you are lucky to have the bacteria already in the soil. You will know if you have them when you pull up the cowpeas and see if there are nitrogen fixing nodules on the roots.
For a green manure to work, the legume should be tilled under at flowering for maximum benefit.
It is only when the plant decomposes that the nodules release the nitrogen back to the soil.
https://www.agriculture.gov.sk.ca/inocul ... ulse_crops
Some inoculents need to be activated by mixing the inoculent with a sticker (mine called for molasses) and the seed, then drying the seed in the shade. It had to be planted within four hours of the activation. Others are designed to just shake around the seed in the planting hole.
Inoculent is not necessary if you are lucky to have the bacteria already in the soil. You will know if you have them when you pull up the cowpeas and see if there are nitrogen fixing nodules on the roots.
For a green manure to work, the legume should be tilled under at flowering for maximum benefit.
It is only when the plant decomposes that the nodules release the nitrogen back to the soil.
https://www.agriculture.gov.sk.ca/inocul ... ulse_crops
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jal_ut
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It is my thinking that once you have the organisms in your bed, they will persist for many years. I know that is the thinking of the local farmers who raise alfalfa.
It is also noted that the bacteria do fix nitrogen, but not much of it is available to the plant on which the nodules are formed. It is of more value to the crop that follows the alfalfa. Then only if the remains of the plants are tilled in. This is why the farmers always crop the alfalfa for 3 or 4 years then follow it with wheat.
It is also noted that the bacteria do fix nitrogen, but not much of it is available to the plant on which the nodules are formed. It is of more value to the crop that follows the alfalfa. Then only if the remains of the plants are tilled in. This is why the farmers always crop the alfalfa for 3 or 4 years then follow it with wheat.
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Jardin du Fort
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jal-ut said
So is there a way to just put the inoculant in the soil, instead of on the seeds? Can that work, or do you have to put it on the individual seeds?It is my thinking that once you have the organisms in your bed, they will persist for many years. I know that is the thinking of the local farmers who raise alfalfa.
That's a fair point. I was thinking that you just put it on the pea seeds, tuck them in the soil, and call the soil innoculated. Now, the rhizo works through the peas (in the root nodules), so there is a good reason to apply it directly to the seeds instead of just randomly in the bed and hope that one will come across the other. That is, if you want to use just a little bit, then put it where it really needs to be. On the seeds. Of course, once established in the roots, the roots should spread it through the bed, wherin one can hope that it'll still be there next season.
The rhizobacterium species is important. Different species prefer different legumes. Cowpeas and alfalfa are pretty promiscuous and will form associations with many different kinds of bacteria. Usually you buy the type of inoculent for the legume you are planting. The easiest one to find was the cowpea inoculent. Proximity to the root is important. Rhizobacteria don't move very much so they need to be near the root to infect it.
It is true that rhizobacteria can persist in soil without a host for years under the right conditions. However, some soils do not retain the bacteria for whatever reasons. Mine did not. I have to innoculate every time if I am planting a cover crop. I believe the bacteria cannot compete with the native soil denizens. I know some other people who never have to inoculate because they have naturally high concentration of nitrogen fixers.
Sunhemp also uses the cowpea inoculent. The advantage is the deeper root system. Most inoculents associate with shallow rooted plants so the nitrogen that is formed will stay within the top 8 inches of soil.
The maximum benefit of nitrogen fixation is when the legume flowers. After that energy is diverted to the seed.
Also, the bacteria create the nitrogen to consume it themselves and the beans get some of that too, that is why the crop must be tilled under to get the benefit.
If there is too much nitrogen already in the soil or you add nitrogen, the bacteria get lazy. They will not make nodules if they can get the nitrogen from a readily available source.
If you have a healthy source of nitrogen fixers, you will not have to keep inoculating the seeds. You should be able to grow a healthy crop, spending a lot less on N fertilizer.
Johnny seeds is a source of inoculents. See link below.
https://www.johnnyseeds.com/c-217-inoculants.aspx
Below are some other links. I found a good one, very technical but thorough but can't find it now. It was a scientific article from Canada.
https://www.caes.uga.edu/applications/pu ... 0990_1.PDF
https://www.youtube.com/watch?v=0Opoy7GQWN8
https://www.ext.colostate.edu/pubs/crops/00305.html
https://www.agriculture.gov.sk.ca/inocul ... ulse_crops
https://www.public.iastate.edu/~teloynac/354n2fix.pdf
It is true that rhizobacteria can persist in soil without a host for years under the right conditions. However, some soils do not retain the bacteria for whatever reasons. Mine did not. I have to innoculate every time if I am planting a cover crop. I believe the bacteria cannot compete with the native soil denizens. I know some other people who never have to inoculate because they have naturally high concentration of nitrogen fixers.
Sunhemp also uses the cowpea inoculent. The advantage is the deeper root system. Most inoculents associate with shallow rooted plants so the nitrogen that is formed will stay within the top 8 inches of soil.
The maximum benefit of nitrogen fixation is when the legume flowers. After that energy is diverted to the seed.
Also, the bacteria create the nitrogen to consume it themselves and the beans get some of that too, that is why the crop must be tilled under to get the benefit.
If there is too much nitrogen already in the soil or you add nitrogen, the bacteria get lazy. They will not make nodules if they can get the nitrogen from a readily available source.
If you have a healthy source of nitrogen fixers, you will not have to keep inoculating the seeds. You should be able to grow a healthy crop, spending a lot less on N fertilizer.
Johnny seeds is a source of inoculents. See link below.
https://www.johnnyseeds.com/c-217-inoculants.aspx
Below are some other links. I found a good one, very technical but thorough but can't find it now. It was a scientific article from Canada.
https://www.caes.uga.edu/applications/pu ... 0990_1.PDF
https://www.youtube.com/watch?v=0Opoy7GQWN8
https://www.ext.colostate.edu/pubs/crops/00305.html
https://www.agriculture.gov.sk.ca/inocul ... ulse_crops
https://www.public.iastate.edu/~teloynac/354n2fix.pdf
The cost of this stuff is something like $10 "for 100 seeds". Presumably one could get it in bulk for less, but if the bulk only lasts one season, why would I do that?
That's an excellent point about fertilizer. A handful of cheap grass fertilizer may do as much as the innoculant does, though it may get leached more than nitrogen fixed in root nodules.
Can I ask "imafan26", how do you know you have to innoculate? It would be great to be able to tell if the rhizobacterium had moved comfortably into my soil on a perrenial basis.
That's an excellent point about fertilizer. A handful of cheap grass fertilizer may do as much as the innoculant does, though it may get leached more than nitrogen fixed in root nodules.
Can I ask "imafan26", how do you know you have to innoculate? It would be great to be able to tell if the rhizobacterium had moved comfortably into my soil on a perrenial basis.
If you are using nitrogen fertilizer you do not need to inoculate.
In fact if you choose to inoculate you don't want to add any additional nitrogen fertilizer because the bacteria will always go the route that uses less energy. If there is a ready source of nitrogen they don't need to work for it and there won't be many nodules formed.
Inoculants are designed to be used with specific legumes. The legume and rhizobacteria have evolved to be mutually dependent. Rhizobacteria though are not very mobile in the soil. They need to be near the host to send out an infectious thread to attach itself to the root hair of the legume. Having the inoculant in the soil, but not near the root, does not promote nodulation.
If your soil is naturally rich in nitrogen fixing bacteria you do not need to inoculate.
You will be able to tell. When the legume is about 4-6 weeks old, carefully dig one of the plants up. You don't want to pull it because you want to examine the roots. If there are a lot of nitrogen fixing nodules on the root, you don't need any inoculant. If you cut the nodule they will be reddish brown inside.
If there are only 0-4 small nodules, then essentially you need to inoculate.
If you inoculate, and you do not add any additional fertilizer the nodules should at least double or triple.
If the rhizobacteria persist in the soil, you should not need to inoculate the successive crop. If the very next crop is not a legume, say rice for example, then you will need to inoculate. However, if you are doing successive plantings of legumes and if the next crop goes back to the baseline nodulation of 0-4, then the rhizobacteria did not persist and you would have to inoculate each time. to increase nodulation.
If the second planting of legumes do show good nodulation, the rhizobacteria survived in that soil environment. Inoculation of the second crop is not only unnecessary, it usually won't show any improvement so it will be a waste of time and money.
When I grew the first cowpeas, alfalfa and sunhemp there was 0-4 nitrogen fixing nodules. Mostly zero.
The second crop of cowpeas were inoculated and the nodules increased to 8-12 nodules with every legume having nodules.
The successive crop after that was not inoculated. If the bacteria had persisted, it should have similar nodulation to the previously inoculated crop. It did not. That crop went back to 0-4 nodules.
There are many organisms living in the soil competing for food, some are mutualistic like the nitrogen fixing bacteria. Most are predators and fill their own niche in the soil web. When you add a packet of inoculant to the soil without being near the host, the bacteria may survive for years. On the other hand what is in a packet is like spit in the ocean. There are far more organisms living in the soil that are already adapted to the existing conditions. The rhizobacteria may be consumed or not be able to compete and survive.
As to the cost effectiveness of inoculation. Inoculation when it does work, reduces the need for fertilizer. Since it is a slow process, there is little danger of over fertilization and damaging the soil and waterways with excess fertilizer. It will help to heal the soil taking out the excess nutrients and salts that cause imbalance in the ecosystem.
If you have a healthy ecosystem already, the bacteria may already be in the soil in sufficient numbers and you won't even have to inoculate at all.
I kept my packet in the refrigerator. It was the closest to the ideal tempeerature. The rhizobacteria also do not like light. The packet tht I got contained living bacteria, not dried. Most living things do not like extremes and are highly perishable.
https://users.rcn.com/jkimball.ma.ultran ... ation.html
https://soils.usda.gov/sqi/concepts/soil ... d_web.html
In fact if you choose to inoculate you don't want to add any additional nitrogen fertilizer because the bacteria will always go the route that uses less energy. If there is a ready source of nitrogen they don't need to work for it and there won't be many nodules formed.
Inoculants are designed to be used with specific legumes. The legume and rhizobacteria have evolved to be mutually dependent. Rhizobacteria though are not very mobile in the soil. They need to be near the host to send out an infectious thread to attach itself to the root hair of the legume. Having the inoculant in the soil, but not near the root, does not promote nodulation.
If your soil is naturally rich in nitrogen fixing bacteria you do not need to inoculate.
You will be able to tell. When the legume is about 4-6 weeks old, carefully dig one of the plants up. You don't want to pull it because you want to examine the roots. If there are a lot of nitrogen fixing nodules on the root, you don't need any inoculant. If you cut the nodule they will be reddish brown inside.
If there are only 0-4 small nodules, then essentially you need to inoculate.
If you inoculate, and you do not add any additional fertilizer the nodules should at least double or triple.
If the rhizobacteria persist in the soil, you should not need to inoculate the successive crop. If the very next crop is not a legume, say rice for example, then you will need to inoculate. However, if you are doing successive plantings of legumes and if the next crop goes back to the baseline nodulation of 0-4, then the rhizobacteria did not persist and you would have to inoculate each time. to increase nodulation.
If the second planting of legumes do show good nodulation, the rhizobacteria survived in that soil environment. Inoculation of the second crop is not only unnecessary, it usually won't show any improvement so it will be a waste of time and money.
When I grew the first cowpeas, alfalfa and sunhemp there was 0-4 nitrogen fixing nodules. Mostly zero.
The second crop of cowpeas were inoculated and the nodules increased to 8-12 nodules with every legume having nodules.
The successive crop after that was not inoculated. If the bacteria had persisted, it should have similar nodulation to the previously inoculated crop. It did not. That crop went back to 0-4 nodules.
There are many organisms living in the soil competing for food, some are mutualistic like the nitrogen fixing bacteria. Most are predators and fill their own niche in the soil web. When you add a packet of inoculant to the soil without being near the host, the bacteria may survive for years. On the other hand what is in a packet is like spit in the ocean. There are far more organisms living in the soil that are already adapted to the existing conditions. The rhizobacteria may be consumed or not be able to compete and survive.
As to the cost effectiveness of inoculation. Inoculation when it does work, reduces the need for fertilizer. Since it is a slow process, there is little danger of over fertilization and damaging the soil and waterways with excess fertilizer. It will help to heal the soil taking out the excess nutrients and salts that cause imbalance in the ecosystem.
If you have a healthy ecosystem already, the bacteria may already be in the soil in sufficient numbers and you won't even have to inoculate at all.
I kept my packet in the refrigerator. It was the closest to the ideal tempeerature. The rhizobacteria also do not like light. The packet tht I got contained living bacteria, not dried. Most living things do not like extremes and are highly perishable.
https://users.rcn.com/jkimball.ma.ultran ... ation.html
https://soils.usda.gov/sqi/concepts/soil ... d_web.html