Electronic soil testers

[Worth1]

My wife made me get a soil tester and I was wondering how accurate they were.
(That's right blame it on the wife.)


I tested the soil were I have some oddball stuff growing and it said it was to fertile and too acidic
The ph was in the 3 range
I then stirred in a goodly portion of wood ashes to raise the ph and it came up to 7 and the fertility was in the ideal area.

Does anybody use these things?
Or should I just do like I always do and look at how the plants grow and what they look like.
At least I could use it for a reference to see any changes I made in the soil.
I honestly don’t see how it could measure fertility accurately.

Worth

[snappybob]

What other parameters does it measure? Was it expensive? If it was affordable then it sounds too good to be true.

[Worth1]

Honestly I looked at the thing at the store and put it back up.
My wife thought I was being a tight wad and unknowing to me put it in the basket.

So now I have it.

It only tests soil PH and fertility.

I have never taken much stock in such devices and would just like to know if the thing is worth a hoot.

I have always had great luck just observing plant growth and researching the soils in my area.

I can’t see the thing being much more than an ohm meter and I have Fluke multi meter that I use for my work.

I think I will try my fluke meter in the same soil and see what I can come up with .

I have also looked on the web for reviews and the only place I could find any information was at garden web with mixed results, with one rather fowl rude reply as is common for that place.

I have also looked here and found nothing on electronic soil testers.

Look I don’t care if the response is a negative one I would just like to know if anybody has used one and what they think of it.
It only cost me $18 so it’s not like I spent a lot of money.

What I do plan to do is use the thing as directed, get the results then send a soil sample off for a soil test.
I will also get a test kit to test it on my own.
Ph paper and so forth.

Then I will compare the results and post it back here for all to know.

Worth

[dcarch]

Originally Posted by Worth1

---------I honestly don’t see how it could measure fertility accurately. Worth

I hope you are talking about soil fertility

I think it can measure PH accurately, but in one single spot only. PH may vary from one area to another. For instance, PH cannot be measured in dry soil.

I don't remember everything in Chem 101, I think moisture contain may be a variable, and I think different chemical compositions can have the same PH value, therefore it would not be a measure of fertility.

dcarch

[Tania]

I used it, and did not have too much luck with it, as when testing my soil, it was always showing neutral pH (although I do know for sure that my soil is acidic!), and very low fertility.

The only time I saw it showing a different pH when I put it into a lemon juice. It showed high fertility in a glass of water with 10-10-10 liquid fertilizer added.

My conclusion was that this devide is great for measuring fertility and pH in liquids, but not in soil.

My $0.02

[dcarch]

Originally Posted by Worth1

---------- I can’t see the thing being much more than an ohm meter and I have Fluke multi meter that I use for my work.

I think I will try my fluke meter in the same soil and see what I can come up with . ---------
Worth

No, not an ohm meter, its a Galvanometer (Gotcha ). (or a digital meter)

If you have a multi-meter and you set it to measure ohms, it would be a measurement of moistrue contain (conductivity) of your soil.

If you set it to measure volts, you will be using it to measure PH. But before you do that, you'll have to use two different metals for the probes, so that when you insert them in wet soil, they will generate a small amount of electricity for your meter to measure.

dcarch

[Worth1]

dcarch I should have known.

Thats why Tania could read Ph in a lemon, (the acid content.)
It's a small battery with about 2.5 volts.

Tania did you make a mud slurry from the soil? That is the way I got the Ph to change when I added wood ash.
It has to be about like gravy.
it also has to be distilled water or filtered water with no chlorine in it.

Chlorine is a base so it will give a false reading of alkaline soil.

Worth

[dice]

I saw a pro pH tester for hydroponic or industrial use on
the WWW the other day. It came with a neutral calibration
agent, a dry substance that you mix X grams of with Y
milliliters of water, test that, and adjust the meter so that
it reads neutral pH. Then it is ready to give accurate results
on other solutions *dissolved in water*.

[Worth1]

"""""I hope you are talking about soil fertility """"""

dcarch So thats why I couldn't figure out how to use it.

That clears up things a lot.

Worth

[the999bbq]

I bought one of those electrical 3 in 1 tools too but haven't used it that much - the arrow moves so it does something, don't know if it is reliable or waht you have to do to get some relatively useful results from it...

what I do not is that you shouldn't leave it in a plant container (and forget it for some time) the probes oxidate so I think it is broken now...

[huntsman]

I have one and figure it knows more than I do...

Did anyone ever find out whether or not these things can, in fact, be relied upon?

[dice]

I tested a cheap Rapitest electronic pH meter with neutral
buffering solution. It was reading about .1 low (6.9) in the
neutral pH solution.That is all that I know about them.
Close enough to see if you need to make radical adjustments
to soil pH, but otherwise, ....

I do not know what exactly the "fertility" part of a multi-probe
could possibly be testing with electronic current.

(Note: according to what I read at a xeriscaping web site,
your average South African soil tends to just slightly alkaline,
based on what native plants from your area seem to be
adapted to, so you probably do not need to add lime to raise
soil pH. If you want to add calcium, use gypsum.)

[huntsman]

Cool, thanks dice!