- Test soil pH with the Dual Probe Meter
- Suggest a viable solution for correcting the soil pH
pH is measured on a scale from 0 to 14, where 7 is neutral. Readings below 7 are considered acidic and those above 7 are considered alkaline. Nutrient availability is tied to pH levels and is therefore critical to plant development. The pH of the soil is also important for the microbial activity. If pH drops near 5.5 then microbial activity will begin to decline.
Regular testing of the soil’s pH enables gardeners to make subtle adjustments using natural amendments. This practice is often performed in Spring before planting begins and in late fall after the final harvest. For indoor growers, monitoring pH is critical since soil volume is limited and any imbalance can produce more profound results on plant development.
Knowing how to effectively test the pH of your soil is imperative and can be done easily with the proper tools.
Tools & Materials
- Dual Probe pH Meter
- Scrap paper
- Pen or pencil
Introduction (10 minutes)
Begin the lesson by defining pH and describing the role it plays in maintaining healthy soil. Share examples with the Students that illustrate the impact of soil that is either too acidic or too alkaline.
Activity (20 minutes)
Using the Dual Probe pH Meter, have Students individually test the soil of the raised planters in different locations. Then take the lesson outside to test soil in various locations including drainages, near downspouts, under trees, or along slopes. Record the results of each location on a piece of paper, including the specifics of the location.
Discussion (10 minutes)
Which areas tested acidic? What could we add to amend those areas? Which ones tested alkaline? What could be added to those areas? Why do you think we got those results?
Assessment (5 minutes)
Use the following questions to assess the Students before and after the lesson. Tally the responses of the group in the Assessment Tracking Log for comparison:
- By a show of hands, how many of you think the soil is different in each of the raised planters?
- Now that you know you know how to use the pH Meter, how many of you think you could properly test soil pH on your own?
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