pH sensor test

Soil pH Meter, pH soil test Kit

A soil pH meter gives you fast and very accurate readings of your soil pH. It’s the most accurate at-home method of determining your soil’s pH.

These days pH meter for soil is convenient, well designed and pocketable little devices. And an awful lot cheaper than they used to be. But don’t be tempted to buy a really cheap soil pH tester – the type you are likely to see at garden supply centers – as they are simply too inaccurate. Instead of a really cheap meter you would be far better of with one of the decent soil pH test kits for the same money instead.

Soil pH meters come in various shapes, sizes and designs. Some have two probes that you place into the ground, and some have a single probe with two plates. Others are handheld devices where you place a sample inside a dish or spoon-like receptacle within the device itself.

single probe ph meter   scoop ph meter   handheld probe ph meter
Soil pH tester examples – don’t buy the really cheap ones

Most upmarket soil pH testers will come with replaceable electrodes. It is worth double-checking though, as electrodes do not last forever, and if you’re spending a fair amount you don’t want the life of your meter limited by the electrode.

How to test soil ph with pH meter?

  • To maintain accurate readings, calibrate your meter using standard pH buffer solutions. (check instructions for your meter)
  • Rinse in distilled water between samples
  • Soak in distilled water if not used for a month
  • Collect multiple samples across your garden, but don’t be tempted to mix them to get an average – test each one.

Ph soil test Kit

Soil pH test kits give the gardener rapid results cheaply, which can mean big improvements to your garden.

I recommend soil pH test kits which use a special liquid that, when dropped onto a crumb of soil, changes color according to the degree of acidity or alkalinity of the sample. This can then be compared directly with a color chart to get the reading. Some kits of this type supply a small china dish to hold the sample while others use glass or plastic tubes. A low cost unit which uses strips of wax paper is perfectly satisfactory once you learn to juggle the folded paper and read it against the chart.

liquid soil test kit           paper soil test kit

Be sure to buy a soil pH test kit that gives readings in direct pH figures, not in some mythical A, B, C system or in Roman numerals. Kits of the latter type are often sold cheaply or given away, but usually have to be used with a special product. Many of these products incorporate undesirable chemicals (such as aluminum sulfate used for acidifying) which you want to avoid.

Your first step in making a pH test is to get a uniform sample of the plot being tested. Don’t use surface soil (roots rarely grow there) but dig down six inches. Avoid large lumps of organic matter unless you have a true organic soil such as peat or muck.

Soil should be moist for several days before you test it. (Drought affects the pH by killing off large numbers of bacteria, releasing organic acids which result in a false reading.) If the sample of soil used is allowed to dry for an hour or so in a shaded spot, it will give a clearer reading from soil pH test kits when the liquid is run through.

How To Measure pH of soil?

Simple mistakes when measuring soil pH will leave you with results that can ruin your garden. Don’t get caught out.

Do not test cold soil. Cold inactivates bacteria, resulting in a false reading. Wait until soil temperature (not air temperature) has been above 60 degrees for at least two weeks, then test.

pH sensor test

When measuring soil pH, don’t neglect the subsoil, unless you are the lucky owner of a four-foot-deep black prairie loam. We forget that if surface soil is only six to ten inches deep, most roots of many crops will grow through that upper layer and get the majority of their nourishment from the subsoil. In checking soil where deep-rooted trees and shrubs are growing or will be planted, perhaps only subsoil need be considered.

Several years ago I saw a good example of why subsoils should be checked. A friend of mine north of Chicago had some magnificent oaks growing at the foot of a steep hill on his property. Heavy washing rains fell all spring, and suddenly my friend noticed that the oak leaves were beginning to turn yellow. A tree man sprayed them with an iron solution and they turned green for a while but soon reverted to yellow.

Tests of the surface soil around the oaks showed it was fairly high in pH, about 6.0, but low enough so that some iron would stay in solution. When measuring soil pH of the subsoil however, we found it tested 7.5. This we diagnosed as a temporary alkaline condition produced by lime washed out of the upper part of the hill by the heavy rains and carried down the hill, along a gravel layer just under the surface, to the roots of the oaks.

Holes bored around each tree and filled with ferrous ammonium sulfate soon brought about improvement in leaf color and tree growth. Drains to lead rain-wash from above into side channels, away from the oaks, prevented further trouble.

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