An experiment inspired by the story of microbes

I did a little experiment lately to see if inoculating with soil microbes were for me. The results were inconclusive, but it's inspired me to try again.

Inspired by this thread, I tried an experiment. Unfortunately, in my enthusiasm, I made some pretty big blunders that gave me inconclusive results, but I'll probably try it again soon.

An area of new garden built on poor soil. I have growing there young flax, safflower, mustard seed and amaranth. They were all quite small and showing signs of stress.

I poured a bucket of fermented nettle tea on the soil for half of them. That was about two weeks ago. The plants where the tea went, are now about 4 times as tall and super healthy compared to the others. That's nice. Maybe it's doing something... only...

The problem is I didn't do the experiment properly.

I failed to water the other half of the plants, so of course they are stunted. It has hardly rained in 3 weeks.

I also forgot that I applied a huge amount of llama manure to half the area, the half I put the nettle tea on. Llama berries make things grow fast and healthy. Llama berries seem to need moisture for the plants to get the benefit of them. The nettle tea provided that moisture.

So the results were good, but I set up the experiment wrong.

Did the microbes help? Maybe. Results from my first try are inconclusive.

This got us thinking of what an experiment of this nature would look like? What is the value of this sort of thing?

I think another experiment is in the works. This one is going to need better planning and control group, but I'm quite excited about it and willing to put the effort in.

I'm very much a qualitative kind of farmer. That looks bigger than that, that one is more read... &c. It seems to me that there are a couple of people who want to watch the experiment and gather some quantitative (numbers, how much taller, what shade of red, &c) data from this trial, so I will do my best to gather it.


This kind of small trial fits very well with permaculture. I think the first principle is observation. One of the other principles is to do small changes and observe the results.

First things I want to know is how am I going to make my microbe mix (for as little money as possible - aka, none) and what measurements should I take before I begin?

Here are some soil tests you might do before and after: http://www.ext.colostate.edu/mg/Gardennotes/214.html

My suggestion is to treat it as a pilot study to investigate whether the claims of people using microbe brews actually are supported empirically. Sadly, this does mean that you're going to need to do some basic weighing and measuring but, in answer to your question, I would suggest following the instructions for making such a microbe brew. Share the method with us before you start, and update us if you have to change it.

When I studied child psychology I learned that few plans survive contact with the enemy...

What is it that you want to compare? Microbial brews with a control? Microbial brews, llama dung and a control?

If the microbial tea has nutrients in it, (most do) pasteurize half the brew, and use that as a control. This should be pretty good. The water and nutrient content will be the same, only the organisms will be missing.

It would probably be better if the area you are experimenting in has homogeneous soil and light conditions. And keep the two rows/ plots away from one another.

Gilbert Fritz wrote:If the microbial tea has nutrients in it, (most do) pasteurize half the brew, and use that as a control. This should be pretty good. The water and nutrient content will be the same, only the organisms will be missing.

It would probably be better if the area you are experimenting in has homogeneous soil and light conditions. And keep the two rows/ plots away from one another.

That was my first thought, but it would also be useful to know if either the microbial or pasteurised version enhances or inhibits seed germination. My inclination would be to have an untreated control, and leave the llama dung out of the equation, or conduct a separate trial with llama dung against compost tea. Much depends on how much seed she has available.

I agree completely about keeping the plots separated. Bacterial populations can multiply exponentially in good conditions.

Some general suggestions if this is your first foray into mini field trials:

1) Prepare for failure....
2) Prepare for failure, but have a good bottle of Oatmeal Stout on hand....
3) KISS---not "Keep It Simple, Stupid", which is kinda mean, but "Keep It Stupidly Simple"

So, consult others on the tea preparation, but possibly just decide on a certain diverse combination of weeds gathered on a certain day, noting for each if they are in vegetative, flowering, or seed-setting state.

I would not worry for now about pre-testing the soil, but you may want to take a spade-full and keep in in a sack for later analysis. The more important comparison will be between treatments.....for now. (KISS)

There may be sites like Johnny's Seeds that have charts indicting mustard plant (or other greens/herbs) populations per unit area....you could consult these to see how many plants you might be able to comfortably get into the individual plot size that you have in mind. (If you want to see how the plots are behaving years into the future, mark them with deep, steel stakes....or a NASA-grade GPS....so long as it's not in inches )

Then you would want to consult with others about (a) number of plants per plot and (b) number of replicates within each treatment in order to hedge towards getting some useful data back from the efforts, and (c), as other have already been offering, the type and number of treatments, which again for a first experiment, I would keep to a minimum (I like Gilbert F's suggestion of pasteurized tea as one treatment, to remove the exogenous microbial activity, but retain the chemical constituents). The design can grow and get out of hand quickly, so try to keep treatment numbers low if possible.

Always keeping in mind--- 4) Prepare for a hailstorm the night before you plan to collect your yield data.
All this just MHO for keeping it simple the first go-round.

Okay, keep it simple: do it Gilbert's way?

"....do it Gilbert's way?"

Again, lots more to consider in terms of tea composition, plant populations, replicate numbers, etc., but for simple starter treatments maybe 1) water, 2) pasteurized (boiled?) tea, and 3) tea. ...??

Mhm. I agree, but I think there are two points to this exercise:

1) gain some useful data
2) teach R and others how to conduct simple field trials

You might want to reverse the order on those.

Both are good...I wouldn't prioritize one over the other. But I was glad to have found an open-access website that allows most if not all to just give it a whirl and then be able to ask questions about their approaches and data entry. For the record, I hate stats as well...good thing my sister is a whiz. Tsk, Tsk, Neil.... one of my intro texts was from your countryman: http://www.genetics.org/content/167/4/1529
As you noted some training in psychology, my real admiration was for Ian D. Suttie, who in my mind pre-dated John Bowlby with 'attachment theory'....

...but I digress.

...it would also be useful to know if either the microbial or pasteurised version enhances or inhibits seed germination...

My guess is that there should be no difference.
A seed contains everything it needs to germinate except water, sunshine and warmth.
Once it germinates, then it would utilize any amendments available, but not before.

So, who wants to pitch an experimental design?

Bear in mind it's 0130 here.

1. Figure out what one question you specifically want to answer- i.e. does microbial tea perform better than water? Do the microbes in the tea make a difference or is it just nutrients? Is microbial tea better than llama pellets.

2. Set up an experiment to answer the one question. A good one would be is microbial tea better than water-
a. get two equal plots of land far enough apart that the water/tea would not cross contaminate. they should be equal for baseline fertility, pH, sunlight- etc.
b. Figure out which plant you want to put in and in what form (seeds, seedlings, mature plants of the same size).
c. determine how often and when you will be applying treatments- i.e. 1/2 gallon every 3 days from the equal sized green watering cans (I suggest using equal but different cans or really cleaning the can
between treatments)
d. How will you account for rain? Will you still apply treatment on rainy days
e. Decide how long you will go for (30 days?) and what your standard of improvement is (height? production? viability?)

3. Apply the above, do not change from your prescribed course of action

4. record results on the prescribed day

5. let us all know how it goes!

John Polk wrote:

...it would also be useful to know if either the microbial or pasteurised version enhances or inhibits seed germination...

My guess is that there should be no difference.
A seed contains everything it needs to germinate except water, sunshine and warmth.
Once it germinates, then it would utilize any amendments available, but not before.

I'm less sure. Seeds also involve tough coatings, which might be broken down by bacteria and/or fungi and many plants exude compounds to inhibit germination. I would not be surprised if they also encouraged bacteria that did the same.

Liz: good stuff, but

2a) bear in mind that multiple plots using the same conditions help to control for unknown variables. See here, pp 12-13. https://www.permaculture.org.uk/sites/default/files/page/document/research_handbook_version_1.5.pdf

It's a pilot study, and R has only limited space and limited seed, so that kind of repeated split-plot design may be impractical, but I think it's desirable. It also reduces the probability that any effects are the result of chance.

Microbial tea will be better then water, at least due to the nutrients.

Gilbert Fritz wrote:Microbial tea will be better then water, at least due to the nutrients.

You think. I think so too, but the point is to check. Testable hypothesis. These are good....

How much space/seed do you have for your trial, R?

Neil Layton wrote:How much space/seed do you have for your trial, R?

I'll go find out.

Water is my main limiting resorse as we are entering our drought season.

The microbes thread seems to imply water might not be needed beyond that supplied with the microbe tea? Or maybe I was misunderstanding?

I was wondering that myself. The microb tea takes water to make and or apply, so limited water is something to take into account when designing the experiment.

The area I would like to use is about 3 by 20 feet. The measuring tape didn't do metric.

R Ranson wrote:I was wondering that myself. The microb tea takes water to make and or apply, so limited water is something to take into account when designing the experiment.

The area I would like to use is about 3 by 20 feet. The measuring tape didn't do metric.

You need a better measuring tape.

So, about 90cm by about 600cm.

If we assume the equivalent of 1m square, but rectangles of 90cmx110cm, plus an isolation distance, that gives four plots. I'd prefer more than 40cm isolation distance, but we have to work with what we've got.

I'm thinking two pasteurised control plots and two intervention plots.

What do the rest of you think?

Would it be best to also add a complete control plot, with no unusual additions? Or would that over complicate things?

Gilbert Fritz wrote:Would it be best to also add a complete control plot, with no unusual additions? Or would that over complicate things?

This should definitely be there as the Null hypothesis is that it is no different than regular. To test that you have to have a complete control. Which is why I suggested one with an equal amount of water as is being applied in tea.

Neil Layton wrote:Liz: good stuff, but

2a) bear in mind that multiple plots using the same conditions help to control for unknown variables. See here, pp 12-13. https://www.permaculture.org.uk/sites/default/files/page/document/research_handbook_version_1.5.pdf

It's a pilot study, and R has only limited space and limited seed, so that kind of repeated split-plot design may be impractical, but I think it's desirable. It also reduces the probability that any effects are the result of chance.

Fair point, I guess in most studies I've seen have had a high enough population number that it equals out, but in those populations you often cannot control for location as easily.

I would argue that in this case you don't need a 'control' as in a plot with only water applied. There's so little area to begin with, I think Neil's design is pretty good. It has replication, isolation, and will test the effect of the microbes on his/her soil. Also, there are no failures! You may not get the result you wanted but you will always get information.

anne weiland wrote:I would argue that in this case you don't need a 'control' as in a plot with only water applied. There's so little area to begin with, I think Neil's design is pretty good. It has replication, isolation, and will test the effect of the microbes on his/her soil. Also, there are no failures! You may not get the result you wanted but you will always get information.

If there's no water control you're not answering the question of whether the microbial tea makes a difference compared with water. It all comes down to what question you want answered.

Neil Layton wrote:Mhm. I agree, but I think there are two points to this exercise:

1) gain some useful data
2) teach R and others how to conduct simple field trials

You might want to reverse the order on those.

These are my goals too. For me, goal 2 is most important. Even if the result is inconclusive, I think the simple practice of setting up small scale experiment and going through with it is an excellent skill to have - like how to sharpen a hoe.

I think it needs to be fairly simple for this first test. Something easy to make and easy to reproduce (in case others want to join in and experiment at home).

I'll have to go back and re-read the thread that inspired this, but I think it was said that the results were visible in a month. I would like to run this from 6 to 8 weeks (from seed in the ground). So long as it's over by the end of August, that's when I plan to get the next crop in that bit of land.


So long as it's simple, affordable, low water, and simple, I'm fine with putting in the work and doing the observations.



This is the rain star for the nearest weather station. We're a bit dryer then there, but it gives you the general gist that we can expect very little rain for the next few months (unless they are right about it being a wet summer - we'll see).




Here's the plot in its current state (it's the sad bit between the lentils and the chickpeas - even the weeds don't want to grow there):





Pretty sad looking stuff. A strip about 3 feet wide, running north-south, for just over 20 feet. It's on a recently made terrace which was tilled for the first time last fall, but I hope to disturb the soil a minimal amount from now on. I'll be carrying buckets to the site, so I hope we aren't expecting too much watering going on. The terraced slope is west facing and exceedingly well drained. That side of the ridge, many neighbours have repeatedly informed me that nothing grows, ever, end of story, nothing at all, stop wasting so much time trying, full stop.


To keep it simple, I think I would like to make the tea out of nettles. One plant, known-ish nutrient value. Can we come up with the simplest step by step process for me to follow? Imagine I was encouraging my friend's 10-year-old daughter to participate, write up the instructions so she could follow them.

Liz Gattry wrote:

anne weiland wrote:I would argue that in this case you don't need a 'control' as in a plot with only water applied. There's so little area to begin with, I think Neil's design is pretty good. It has replication, isolation, and will test the effect of the microbes on his/her soil. Also, there are no failures! You may not get the result you wanted but you will always get information.

If there's no water control you're not answering the question of whether the microbial tea makes a difference compared with water. It all comes down to what question you want answered.

Yes, what is the question we want answered?

I am curious if these kinds of results will work in my conditions. It seems a bit far-fetched to me, but then again she could be on to something. I'm insanely curious. If someone is doing something differently than me, I want to know all about it and try it for myself - I don't want to miss out on a good thing.

Perfect timing, there's a small place that had a crop failure (due to poor soil and lack of water - two things this method is supposed to cure). If I go and apply this treatment everywhere, I won't know if it's responsible for things working/not working or not. So I want to make some sort of control, try a little bit and discover if it's worth my while to investigate further.

What question does that give us? It's all shits and giggles knowing the answer is 42, but it doesn't mean anything unless we know what the question is.

Any thoughts on what question will give me the most useful results?

R Ranson wrote:
Yes, what is the question we want answered?
(...)
Any thoughts on what question will give me the most useful results?

Well this is your test- so what is it that you wanted to know about the microbial teas? What question in your mind brought you to try them in the first place?

Liz Gattry wrote:

R Ranson wrote:
Yes, what is the question we want answered?
(...)
Any thoughts on what question will give me the most useful results?

Well this is your test- so what is it that you wanted to know about the microbial teas? What question in your mind brought you to try them in the first place?

Drat, I was hoping to fob off the hard bits onto you guys.

I have poor soil, I want soil that grows healthy plants and yummy food. Can these microbes really transform my soil in as little time as a month or two? Would this method work where I live, in my conditions, with my style of growing things?

But I'm thinking that's not specific enough, is it?

I would compare seeds given plain water, seeds given nettle tea and seeds given boiled and cooled nettle tea. That would answer my questions about whether the fermentation helps, and how much of the help is due to the living organisms in the fermented "tea."

To make the nettle tea, I guess I would put whole nettle plants (? chopped) including roots into a five gallon bucket with rain or dechlorinated water and either stir it twice a day or run an aquarium airstone to keep it aerobic.

Yes, the question is important. Comparing fermented tea to pasteurized tea will theoretically test the effect of the microbes, but not if the tea works at all. If none of the plots show any difference between them, then you could assume the fermentation here didn't help and then you'd have the question of whether or not the tea itself helped. So, you need to determine what information is most important; 1) does the tea work or 2) is the fermentation step necessary?

What we're trying to find out is whether or not the addition of "microbes" (in itself an extremely generic term of very limited scientific value) has any effect on the growth of those plants R intends to grow.

It's actually no more than a pilot study, and will provide us with limited scientific information, but I don't think that's the point. If we were really serious (and had a decent biology lab and a lot of money) about this we would identify the dominant species in the "microbe" culture, relative populations, and so on. We'd also monitor soil populations throughout the trial, and so on.

To me the point is to get people used to gathering and using empirical evidence in permaculture, instead of listening to endless pseudobabble, and to be able to intelligently challenge the pseudobabble when they hear it.

Trials on some but not all compost teas have shown mixed but sometimes very promising results. Others have found a proliferation of E. coli. What will happen here is actually anyone's guess. It's possible the native microbiota will simply reclaim their niches. No effect is definitely a plausible (but not guaranteed) outcome. Application on planting followed by another application when the plants are actually growing might produce better results (when the plants are exuding compounds to encourage growth: it's also plausible some bacteria exude compounds to encourage germination, directly or indirectly: http://phys.org/news/2014-09-irish-teens-idea-bacteria-crop.html).

R is asking the right questions, but lacks the skills to answer them for herself, as do many others here. That is a problem that is eminently fixable.

------------------------------

Okay, I think we have almost enough information to put together a simple trial. The remaining things we need to know are:

1) what is the recommended protocol for making the nettle tea? What quantity of nettles? Rainwater or tap water?

2) What seeds do you have and in what quantity?

To me the point is to get people used to gathering and using empirical evidence in permaculture, instead of listening to endless pseudobabble, and to be able to intelligently challenge the pseudobabble when they hear it.

Just so.

On another point, a microscope capable of identifying microorganisms is not all that expensive, if one wanted to do that down the line.

I guess the question is; does a nettle tea help vegetable growth? and If so, is it the biology or the chemistry of the mix that produces the greater effect?

@anne weiland: "Also, there are no failures! You may not get the result you wanted but you will always get information."

Didn't you see my note above!...."Prepare for failure"

(Hey, dudette....welcome to the party....or pantry....or manure pit! )

But agreed: It is not uncommon to replicate the entire experiment in one year at 6 - 10 different locations....with the prayer that *one* location will actually yield usable data. If all 6 - 10 yield usable data, it's time for champagne and .... perled tapioca.

@Neil L: "1) what is the recommended protocol for making the nettle tea? What quantity of nettles? Rainwater or tap water? -and- 2) What seeds do you have and in what quantity"

For #1, hopefully Charlotte A. or another can chime in with a "beginners protocol". Maybe I'm wrong, but I suspect rainwater will vary less in dissolved components than tap water....would be more consistent than for others to collect rainwater in their area(..?)

I also wonder about using nettles during different life stages and how that might affect the tea. AND ambient temperatures and the affect on fermentation. How many batches of tea will be made? This is where documenting observations can really help you. Isn't this fun??!! I love it!

It is fun, I'm really enjoying it.

Just so you know, I'm not on city water, so no cause for concern about chlorine. Our rain water reserves are running out, so if you want me to use that for the ferment, then I need to know asap.

How much water will I be needing?

@anne w.: "....using nettles during different life stages and how that might affect the tea. AND ambient temperatures and the affect on fermentation. How many batches of tea will be made?"

Agreed, but pull back on those reigns a bit. It was only yesterday that R. Ranson proposed taking this course of action. I'm thinking that, given limited space and time (gardening season in Vancouver, BC in full swing).....*AND* give the wide audience globally that may wish to give it go, it may be prudent to start with the simplest variables possible. Also agree that, if one were to want to duplicate what R. Ranson does as closely as possible, that documentation will be key. Your own acreage would be quite amenable to these studies as well,....I think one variable that would want to be considered quickly is what plant will be used for the study. I thought mustard of some type might be good because (a) it's annual and seed is relatively inexpensive, (b) one could measure both fresh weight biomass as well as seed count, (c) although the growth habit will likely vary a bit regionally, mustard would probably grow at the equator as well as near the poles (okay, the latter is a bit extreme, but you get the idea). If a mustard *variety* were chosen that is most easily obtained by the most number of people, then the variable of genetic difference between experiments would at least be minimized. Of course, none of this stops anyone from doing their own study how they please. But for the sake of comparing treatments and evaluating efficacy, these may be some things to consider.....and hopefully there will be other commentary that offers additional ideas to improve the approaches as this advances in the coming days and weeks.