pH meters, digital soil.

14 years ago

Good morning everyone, its a beautiful cold morning out there isn't it.:^(

Hey,I'm wondering what every one's opinion is of these digital pH meters that you see advertised so much in the seed catalogs, they say all you have to do is stick the probe in the soil and you get an almost instant pH reading, are they any good? are they accurate?

I have an old one that I'm using now but it requires me to gather the dirt and mix with water, insert the prob and wait 10 minutes, and of course I still don't know how accurate they are, but these new ones seem a lot easier to use.

I've always hesitated having a soil sample done by the ext, service because my garden has at least three different areas (types) of dirt, and if I understand the process right that would mean three different tests, am I wrong about this?

It would be nice if you could just stick a probe in the ground and get and instant reading, Ah but that would be to easy wouldn't it? so' what's your opinion?

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Okiedawn OK Zone 7
14 years ago
last modified: 9 years ago
Good Morning!

It may be a beautiful cold morning, but I'd rather have a beautiful warm morning. : )

This is only my opinion but I base it on the advise given over the years by the real experts (not the wannabe ones) over at the Soil, Compost and Mulch Forum here at Garden Web. I don't believe the inexpensive pH meters are accurate unless you are willing to spend several hundred dollars to get a really good one, and I've never seen a pH meter in a garden catalog that would qualify as a really good one. Even if you spent several hundred dollars to get a really good one, you'd still have to be sure to store it properly (in a wet solution at all times) and to calibrate it before every use. Of all the things I'd ever spend my gardening money on, a pH meter, cheap or expensive, wouldn't even make the list. The cheap ones aren't good, they aren't accurate and their reading can vary because of many other factors like moisture levels, how recently you've fertilized, etc.

The old one you already have probably is more accurate than anything you'd ever see in a gardening catalog aimed at home gardeners. It is the mixture of soil/water in the proper ratio that gives you more accurate results than you'd get with the cheap ones made to just stick into the soil. Those are easier to use but notoriously inaccurate. I'm assuming you store your old meter properly and that you always use distilled water so your reading isn't influenced by the pH of your tap water. (Our tap water is usually around 8 to 8.2 but our improved soil is much lower than that, so if I used our tap water in a solution for a pH meter test, it would give inaccurate results.)

If you need to know what is going on with your soil, a soil test is the way to go absolutely, positively every time. Nothing else is a good substitute. I don't think 3 soil tests is the way to go unless you feel like there is a reason your three kinds of soil would test drastically differently. The preferred method for soil testing is to follow the directions given by the soil testing lab and those directions normally tell you to take samples from several areas, mix them together and send in that mixture to get an idea of your soil's overall condition.

The only exception to that would be if you already have an area with highly improved soil and you want to test it and an area with totally unimproved soil that you're going to turn into a new growing area. In that case, I'd do separate tests.

The extension service soil tests are fine. Another very highly recommended soil lab is linked below. It has been around a very long time and has an excellent reputation for outstanding service.

And for what it is worth, those little soil test kits you see in nurseries and gardening catalogs are not highly accurate either. I might as well throw that in now because lots of gardeners buy them and they're a wasted if you're looking for accurate information. A real soil test tells you about so much more than just your nutrient levels and soil pH. It tells you about your CEC and your approximate percentage of organic matter for starters, and to me those are more important than nutrient levels.

Dawn

Here is a link that might be useful: Texas Plant and Soil Lab
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pH meters, digital soil.

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Okiedawn OK Zone 7

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