Soil Test: The Tomato Project

BillsBayou

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This year I'm going to be growing tomatoes to test a couple of of soil amendments. @Joe Dupre' is the one who gave me the idea to use tomatoes to test amendments. We were talking about something else when he mentioned how much he loved Cherokee Purple tomatoes despite the relatively few tomatoes he gets from each plant. I got to thinking that plants that produce few tomatoes will produce few or none if they're not happy. Let's torture tomato plants!

Tomatoes should be a great plant for testing soil amendments. If one soil holds fertilizer better than another, I should get bigger plants and more tomatoes from soils with higher CEC values. I've ordered tomato seeds for "Cherokee Purple", "Aunt Lucy's Italian", "Ethiopia Roi Humbert", "Healani", and "Tiny Tim" from TomatoFest.com. I've never used them before, so I have no idea if they're a good company. I'll start the seeds in peat and transplant to the soil mixes when the plants are a few inches tall.

I have Haydite, Diatomaceous Earth (DE), Red lava rock, Black lava rock, Akadama, Clinoptilolite, and Pine Bark. The permutations are going to be too great for me to do this right, so advise me if you don't like the following test soil mixes:
50/50 Haydite/Pine Bark (my usual bonsai mix)
100% Haydite - I suspect these tomatoes will not do well
50/50 Red/Black lava rock - Not holding out too much hope for these either
100% Akadama - If it's good enough for bonsai, it should be good enough for my tomatoes
100% Clinoptilolite - To compare against Akadama
33/33/33 Clinoptilolite, DE, Lava

Ideally, each group would have 20-30 plants. Yeah, no. I don't have the room. I'll start out with as many plants as I can manage. I only have one bag of Akadama, so that limit's the test. However, I really don't want to find that Akadama is the best because A) It's expensive, and B) It's imported and I want domestic alternatives.

Everything will be getting the same amount of water every day.

I'll be fertilizing weakly weekly. Half-strength organic fertilizer. There's a small organic nursery nearby and I'll be talking with them about what they'd recommend for this test. If plain hadite or lava rock has a low CEC value, I want the fertilizer to be used up before the next feeding. Plants in substrates with higher CEC values should still have plenty of fertilizer by the time I'm adding more the following Saturday.

The goal is to have a wide spectrum of results. I want some populations to barely survive while others to show great results. If everything survives then I learn nothing. In the past I learned that bare rooting and transplanting dwarf kumquats on a hot summer day makes them happy no matter what I soaked them in. While on the other hand, you get better looking basil by using plain water because adding Superthrive made the basil look even weaker.

At some point, and to the horror of my wife, I'll bare-root the plants to compare root balls.

Feel free to comment, I hope to begin as soon as I get my seeds.
 

BillsBayou

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Some other notes...

It would be fun to have a way to test the fertilizer run-off. Higher CEC substraits are supposed to hold on to more fertilizer. Fertilizing plants with the run-off should produce opposite results of their water source.

If I feed the plants with a weak solution of fertilizer, low CEC substrates will always be short of fertilizer. However, substrates with high CEC values will be building up their stores of fertilizer as time goes by.

I'm over thinking this.
 

Forsoothe!

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The number of variables you're dealing with makes my head explode.
 

Woocash

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I like it. Personally, if it were me, I would probably just test with one variety, because obviously different tomatoes have different characteristics. That way you wont muddy the water so much with your results and you can carry out fewer experiments. I would also be tempted to do a test in 100% of each medium because by mixing you don’t know which of the substrates are having the most effect.

If you are just purely testing fertiliser retention you could also treat it hydroponically. Water and fertilise them all the same amount, flood them for a set time then allow the runoff to be captured so you can measure how much is retained.
 

Joe Dupre'

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Sounds interesting ..........and exhausting! A little advise. Plant ONE seed per cup or compartment. I went with 2 or 3 per and, you guessed it, they ALL sprouted. Devilishly hard to get them seperated once they get going.
 

Wilson

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Back in the day people grew lots of "tomatos", and were always buying supplies at the hydroponics store!😆 All jokes aside, sounds like a tasty experiment.
 

Shibui

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Just a couple of comments from me:
However, I really don't want to find that Akadama is the best because A) It's expensive, and B) It's imported and I want domestic alternatives.
You should never start a trial with a bias. It is too easy to influence the trial, even unconsciously, to get the results you want. Please give all the mixes a fair go. Even if one appears to be slightly better we can still use any of the other mixes provided we know we are opting for a slightly (or even much) less effective mix.

The goal is to have a wide spectrum of results. I want some populations to barely survive while others to show great results. If everything survives then I learn nothing.
All results are valid. Closer results just mean there is far less impact of the mix than some would have us believe and gives those of us who choose to use local ingredients some validation for our stand. Ditto if everything survives and grows equally well. That just means that any mix is as good as the next.

A little advise. Plant ONE seed per cup or compartment. I went with 2 or 3 per and, you guessed it, they ALL sprouted. Devilishly hard to get them seperated once they get going.
You must have a masochistic streak o_O Always plant 2-3 seeds per pot to maximize the chances of having at least 1 per pot but SNIP OFF any extras leaving the strongest. Way easier than separating multiple seedlings.
 

Anthony

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Since the 80's we have grown tomatoes in our bonsai soil
mix, but at 8 mm size for the inorganics.
Plus a tomato fertiliser,
Works well.
Happy growing,
Anthony
 

Forsoothe!

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Since the 80's we have grown tomatoes in our bonsai soil
mix, but at 8 mm size for the inorganics.
Plus a tomato fertiliser,
Works well.
Happy growing,
Anthony
How big were the plants? What variety & yield? How big was the pot?
 

GailC

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I'd also grow some in regular potting soil so you have a baseline for each variety.
 

BillsBayou

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So many replies, so much to say. Let's begin...
The number of variables you're dealing with makes my head explode.
Same here. But since I'm doing this empirically rather than scientifically, I'll end up with a result that feels right. (the little scientist in my head just hung himself in grief)
I like it. Personally, if it were me, I would probably just test with one variety, because obviously different tomatoes have different characteristics. That way you wont muddy the water so much with your results and you can carry out fewer experiments. I would also be tempted to do a test in 100% of each medium because by mixing you don’t know which of the substrates are having the most effect.
I'm going to do about 6 plants in each group. Not statistically relevant for any one group. I'm hoping that one of these varieties will have a wider array of results from sickly to vigorous. If one variety has negligible results across the board, that's one thing, if they all have negligible results across the media, that's something else. By now, you should be able to tell that I'm making this up as I go.
Put some time into reducing the size, & scope of the experiment. Or you will either give up a third of the way through. Or you will be crushed under the mountains of tomatoes you will end up with at the end. 😉
Crush me!
Sounds interesting ..........and exhausting! A little advise. Plant ONE seed per cup or compartment. I went with 2 or 3 per and, you guessed it, they ALL sprouted. Devilishly hard to get them seperated once they get going.
I'll keep that in mind. Thanks again.
You should never start a trial with a bias. It is too easy to influence the trial, even unconsciously, to get the results you want. Please give all the mixes a fair go. Even if one appears to be slightly better we can still use any of the other mixes provided we know we are opting for a slightly (or even much) less effective mix.
I'll post results with any and all data I collect. Maybe at the end, I'll have starting points to narrow the experiment next year. Thanks for the reminder about biases. I'm glad I free-styled my post. It helps to expose the flaws in my "experiment".
All results are valid. Closer results just mean there is far less impact of the mix than some would have us believe and gives those of us who choose to use local ingredients some validation for our stand. Ditto if everything survives and grows equally well. That just means that any mix is as good as the next.
When I experimented with Superthrive and found that it stunted the growth of my basil plants, I have to keep in mind that my results showed that Superthrive stunts the growth of basil. Expanding that result to all of agriculture may be wrong, but I still don't trust the product. It is my hope that more than half the varieties will show variations in growth between the potting media groups. When I experimented on Hong Kong kumquat, all I proved was that I couldn't kill the plant with my experiment. Was that a fault of the experiment or of the selected species? I think it'd be interesting if one or more of the tomato varieties showed no variation. If I get insignificant differences between 100% Hadite and 100% Akadama across all varieties of tomatoes, then tomatoes are hard to kill, and I need to try another species of plant or tree.
I'd also grow some in regular potting soil so you have a baseline for each variety.
I'll likely do this. Thanks.
No cides - just basil as the companion plant.
I didn't know about basil companion plants. I looked it up and it seems that they do help tomatoes deal with insects and such. I'm going to have to think about this.
 

BillsBayou

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He needs to find one good Italian Grandma and them tomatoes will be gone!

Sorce
My grandfather's family came from Palermo. My wife said she'd marry me if I learned to cook like my grandfather. Many years ago, my mother finished eating spaghetti and daube at my house and proclaimed "I feel like I just had dinner at my father's house," which I took as a great compliment.

Bring on the tomatoes!
 

Lorax7

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I would think inclusion of Boon’s mix would be good to serve as the gold standard reference, since it is so widely used for bonsai.
 
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