Testing Soil pH

How to test your Soil

Scoop up loose soil samples with a clean, dry plastic jar. Avoid touching the soil with your hands to prevent contaminating the sample.

1. Remove any stones and crush any clumps of soil to prevent breaking the delicate glass electrode bulb.
2. Fill up your sample soil up to 3/4 and add distilled water to the jar. Cap the jar tight and shake it vigorously a few times. Let the mixed sample stand for 5-10 minutes to dissolve the salts in the soil.
3. Prepare to log your test result in your data book for later reference.
4. Remove the caps of the jar and your pH meter. Dip the electrode into the wet soil slurry and turn the tester on. Take the reading when it stabilizes.
5. Press HOLD button to freeze the displayed pH measurement. Record the pH reading in your data book.
6. Press HOLD button again to release the reading.
7. Rinse your pH tester in clean water between each use.

Calibrate the pH tester using the instruction provided with your pH meter.

The pH tester used in this procedure should be accurate to ±0.1 pH or better. The soil sample preparation and test procedure is adapted from accepted laboratory methods. Soil pH testing in the field gives small differences between tests. Using the 0.1 pH resolution pH meters minimise these differences.

Most soil pH measurement cannot achieve ±0.1 pH accuracy, even with elaborate laboratory procedures and expensive pH instruments. Usually, soil pH data for many applications do not require testing for better accuracy than a few tenths of a pH or even ±0.5 pH in some instances.

Recommendations for Best Results

Prepare and run at least three tests of the same soil sample to confirm results. Minor (< ±0.5 pH) or no differences between readings indicate good technique and high confidence in results. Larger differences (> ±0.5 pH) require more testing and to discover the source of the discrepency.

We recommend the: 

 or

 And don't forget to order buffers!