Every year for best germination.

Dan

Not so sure I agree. Inoculated half of my beans last year.I have raised beds with excellent soil. If you have good nitrogen levels and good soil it probably makes no difference. In good soil the roots and the symbiotic bacteria will find each other naturally. I saw no difference in my production in either group.

If you are trying to use a legume to build up the maximum amount of nitrogen, you need to reinoculate every year. The bacteria only lasts in large numbers for another year or two at most. By the third year, they are back to normal background levels which is not high enough for maximum effectiveness. I have a 3 year rotation between legumes so I must reinoculate. But if your soil is already really good and you are not trying to build up nitrogen through bacterial fixation, then you do not need it at all. Nitrogen fixation is the cheapest way to improve nitrogen soil levels.

Here is a link that might be useful: GardenForNutrition.org

I can get fair germination without an inoculant - poor with edamame - in organic raised beds with outstanding soil. I get much better germination with an inoculant. Sure, I can plant 3 extra seeds per hole but now I have fewer seeds and I have to thin. I'd rather inoculate and move on.

Dan

Search on "inoculant" in the Bean Forum, where it has been extensively discussed.

I don't bother with inoculant any more. Beans grow fine without it. Nitrogen is easily and economically supplied by fertilizer.

Jim

Here is a link that might be useful: Bean Forum

If the trellis is fixed (the beans are grown in the same place every year), it seems to me that inoculant will be there next year.

the beans are grown in the same place every year),

That is bad practice, so the issue is are the myco persistent in the soil for germination next year?

At any rate, I'm rethinking my inoculum practice, thanks folks!

Dan

That is bad practice if your trellises are easily movable, and also if your beans get sick. I do get my share of problems with other veggies, but the beans are always healthy around here. They are also not myco (fungi), they are bacteria.

As mentioned above, the Bean Forum has had extensive discussions on the topic of inoculent, including the question of annual application. There are several threads on inoculant. The one you might find most useful is linked below. It is a long thread with contributions from three or four of the most knowledgable bean growers around. Toward the end of the thread you will find a report by zeedman on an experiment he conducted on this topic.

Jim

Here is a link that might be useful: Inoculent Thread

The zeedman report is far from usable IMHO. Nonetheless, elsewhere on that forum, Flora pointed out in some thread that there is no inoculant for sale in Great Britain, and perhaps it is yet another consumer product in the US. Good place to start thinking about the need for inoculant...

Dan

Yes, Dan - this is purely anecdotal but I had never heard of inoculant until I started frequenting US forums. It is certainly not mentioned on seed packets, in gardening books and magazines or on TV programmes over here. Google UK only pages and you will find very few references and they are all from commercial agriculture. Somehow we manage to grow beans.

And my wife tells me I don't pay attention! ;o) I'm thinking I'll use the rest of the package - since I have it already - and call it a lesson learned from Flora.

Dan

Not sure I can take the responsibility, Dan. Disclaimer: I only know about gardening where I garden. Good luck.

Forgot to mention. Plants are like people. They can be lazy. If your soil already has sufficient nitrogen, they tend not to make anymore even if you inoculate. So if you have plenty of nitrogen already, inculation is a waste of money and time.

"If your soil already has sufficient nitrogen, they tend not to make anymore even if you inoculate. So if you have plenty of nitrogen already, inculation is a waste of money and time."

I agree, and that pretty much sums up my opinion on annual usage. While there are anecdotal arguments both pro & con, there is very little in the way of scientific evidence in support of annual use for garden culture... unless you want to believe the glowing reports of the inoculant industry (I don't). Flora's comments seem to suggest that inoculants may not be of much value, or they would be more widely available. I would still recommend their use on poor soils, or on new ground... but you can grow legumes quite successfully without them.

"If you are trying to use a legume to build up the maximum amount of nitrogen, you need to reinoculate every year."

Agricultural research I have read supports this, for crops grown under field conditions. Vegetables grown under garden culture can behave quite differently. Beans, based upon my own observations, tend not to be heavily nodulated. This could be a quality of the species, or a response to fertile soil... research I have read supports both. Soybeans & cowpeas, however, have been heavily nodulated in the same soil. I generally inoculate my soybeans, but even when I have not, nodulation has been good... that bacterial strain appears to be very hardy. I will try to post some photos of nodulation on various species this year.

"I can get fair germination without an inoculant - poor with edamame - in organic raised beds with outstanding soil. I get much better germination with an inoculant."

Such results might be possible, if the rhizobia displaces or inhibits disease organisms present in the soil which might otherwise cause seed death. However, as a soybean collector, I have not observed anything similar. I have started soybeans indoors in sterile media, and direct seeded in situ both with & without inoculant, and the germination rate has been the same.

It should be noted that, according to the NSRL (National Soybean Research Laboratory) nodules take 3 weeks to form, before which the bacteria offers no nitrogen to the plant.

"The zeedman report is far from usable IMHO."

To a point, I am forced to agree. Since I followed scientific method, I concede that anything which interfered with the results invalidated the data. The experiment did not go as well as I had hoped for. Quite a few things went wrong, so much of the experiment was flawed. However, that does not mean that there were no results. As an amateur researcher, I felt that I stated my observations & conclusions fairly.

It would have been nice to have had more participation in the experiment, since it represented an opportunity to resolve this recurring question. The lack of enthusiasm within this community was very disappointing. I will continue my experiments in the future, but on other forums. There are inoculant issues other than yield to research, such as impact on disease & insect resistance, and response to environmental stress.

"The zeedman report is far from usable IMHO."

I will accept a portion of the blame for your disappointment on two counts:

1. I probably led you to think the report would offer a clear, conclusive answer to the question. As zeedman explained, real world conditions did not make this possible. It is much easier to throw out speculation and hunches, which is what we usually get on topics like this, than to conduct a controlled experiment, which requires time, effort and garden space.

2. I was one of the Bean Forum members who expressed interest in the experiment, then failed to follow through. Let's see if we can revive the idea over on the Bean Forum and talk it up as we enter the garden prep season when people will be firming up their garden plans for this year.

Jim

Jimster, no one misled me, least of all you. The spirited discussion we had on the Bean Forum several years ago pointed out the amount of misleading & anecdotal information out there, and I hoped to contribute something more concrete for gardeners to consider. Still might, but it may take several years to put it together.

However, when conducting research, it is important not to start off with faulty premises. Just because "B" happens when I use "A", does not mean that "A" is responsible. This conclusion neglects other factors (such as soil, irrigation, and climate) that also influenced plant growth, and overlooks that the results might have been the same regardless. Without the use of controls and measurable statistics, observations are merely anecdotal.

Even if all goes according to plan, my results will only document the improvement (or lack thereof) of annual application, for the species tested, with my soil & climate. Even that would be a good start, and would help answer the question posed by this thread. But results may vary in other locations, which is why I had hoped for testing in several geographical locations.

"Jimster, no one misled me, least of all you."

No, it wasn't you I misled, zeedman. I was referring to Dan, whose expectations may have been raised too high when I referenced your experiment.

I have been rereading that long thread to see if it would be worth trying the experiment again. The thread has an immense amount of information. Some of it would seem to make the need for an experiment moot in terms of practical gardening. On the other hand, there is that curiosity factor...

Jim

Thanks for the dialogue. I'll check out the bean forum

Zeedman

Thanks for the info. I would definately like to see the photos. Good point about field inoculation. I probably work in too much manure to get much benefit in the garden. Do you see red or pink inside your nodules and what variation do you see depending on species?

Hi all back in the UK and I have brought SEEDS! not that I have anywhere to put them :) but ready to go.
to back flora I hadn't heard of inoculants before I lived in the USA, and as much as I didn't garden, my Dad and Pop did and it is one thing on asking gardening friends in the UK! blank looks, no one knows of them.
Yesterday I was in B & Q they are Home Depot same comany and on studing the newly filled shelves I did find inoculant, 3 packets to be precise, but a BIG! advert on the wonders of it!
I have to say not convinced, in fact totally not convinced as I had planted runner bean in the UK, that was all I did with a couple of Tom plants and my US beans where not actually as good after treatment, and because it was a new thing to me I forgot on occation when planting, I couldn't tell the difference in production between those that had been treated and those that hadn't?
PS Flora get a tiny smug feeling, seeds are about the same cost in the UK as the US and everything garden is so much cheeper, easier to get and better made in the UK, at last we can be smug on something :)even if we can't afford a house with a big garden :(

I'll throw in a comment that I feel using innoculant yearly is mostly harmless and maybe beneficial. The problem is that ordinary beans are very poor nitrogen fixers. Cowpeas on the other hand are better than almost all other legumes, possibly excepting a few of the vetches.

I would say to innoculate unless you are either providing fertilizer with plenty of nitrogen, or you are confident the soil is already colonized.

Worth another thought is that there are several different innoculants on the market. The one for beans does not work very well on peas and vice versa.

DarJones