Soil pH can impact a plant’s uptake of nutrients. For healthy, vibrant plants and crops, it’s vital to check the pH of your soil. You can measure soil pH directly from the ground or via a soil slurry. Measuring pH from a soil slurry is recommended when you have either:
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- A standard pH electrode incapable of penetrating the ground; or
- Harder soil or soil that is high in debris such as sticks and stones.
To avoid inaccurate test results, and possibly, suboptimal soil nutrition, knowing how to prepare a soil slurry is essential. This video article demonstrates the correct way to mix a soil slurry for soil pH measurement and the right way to operate your soil pH tester.
Watch Instrument Choice Scientists demonstrate how to prepare and measure a soil slurry the right way.
How to Prepare a Soil Slurry for pH Measurement
- To make the slurry, you will need a scale, the soil sample, a clean container, a spoon, a measuring cup and 100mLs of distilled water. For measuring, you will need a soil pH tester. For this example, we will use 100mLs of water to 50 grams of soil. Amend these volumes to suit your needs so long as the ratio is two parts water to one part soil.
- Take the clean container, place it on the scale and press tare.
- Weigh out 50 grams of soil.
- Add the 100mLs of distilled water to the 50 grams of soil and mix thoroughly.
- Wait at least 15 minutes for the soil to settle. Leaving for this time will give more accurate results. It’s normal to see some separation between the soil and water.
How to Measure a Soil Slurry using a Soil pH Tester
- Once 15 minutes has elapsed, you can use your soil pH tester to measure the slurry.
- The last step is to turn on your selected soil pH tester and place the electrode into the centre of the sample and wait for a stable reading.
- Remember to rinse your electrode thoroughly after use. Repeat the soil slurry mix and measurement on several areas of your soil for more accurate results.