Q: What is “SOIL pH” and why is it important to pay attention to?
A: SOIL pH (or “potential hydrogen”) refers to the measure of acidity or alkalinity of a soil. As indicated in the diagram below, soil pH is charted on a scale between #1 (most acidic) to #14 (most alkaline), with #7 being neutral.
WHY IS SOIL pH IMPORTANT?
Apart from certain plants, for example hydrangeas and blueberries, that (in this case) prefer a slightly more acidic soil, most plants tend to prefer a neutral leaning pH between 5.5 and 7.5, that offers better conditions by which more essential nutrients are made available to plants (nitrogen, magnesium, potassium, sulfur, phosphorus, calcium, etc.).
D.I.Y. HOME SOIL pH TEST
HOW IT WORKS:
When BAKING SODA (sodium bicarbonate) comes in contact with acidic substances, like VINEGAR (dilute acetic acid), for example, the chemical reaction that occurs produces 1.) carbon dioxide gas, 2.) liquid water, 3.) sodium ions, and 4.) acetate ions. The escaping CO2 creates a visible bubbling effect.
Mixing baking soda with acidic soil will also create this effect. And similarly, when mixing vinegar with alkaline soil.
It’s quick & easy! All you will need are the following items:
- 2 GLASS JARS
- 2 fistful sized SOIL SAMPLES (1 cup each)
- 1/2 cup of VINEGAR
- 1/2 cup of BAKING SODA
- 1 cup of water.
HOW TO TEST for SOIL ALKALINITY:
- In the first jar, add soil sample (1 cup)
- Wet soil so that sample is slightly muddy
- Add 1/2 cup of vinegar
- Stir contents. If the sample fizzes and bubbles, your soil pH is ALKALINE.
To lower the pH of your soil, add any of the following:
- Organic compost/mulch
- Pine needles
- Peat Moss
HOW TO TEST for SOIL ACIDITY:
- In the second jar, add soil sample (1 cup)
- Mix a 1/2 cup of water with 1/2 cup of baking soda
- Add mix to jar of soil and stir. If the sample fizzes and/ or bubbles, your soil pH is ACIDIC.
To raise the pH of your soil sample, add any of the following:
- Organic compost/mulch
- Firewood ash
- Garden grade lime
- Bone meal
IF THERE IS NO REACTION for either sample, your soil pH is NEUTRAL.
*This test is intended to give you a more general idea of the pH leanings of your soil. For a bit more accurate a reading, as to the degree of acidity or alkalinity of your soil, you can purchase a soil tester kit at your local nursery/garden center. For an even more comprehensive & detailed analysis, soil samples can be sent in to your local extension office, for testing & other recommendations on how to amend your soil.
When using amendments, such as sulfur, lime, etc., be sure to carefully follow directions & recommended amounts, determined by a professional. That said, the best and easiest way to address most soil issues is to mulch regularly ( at least once a year).