Have you ever taken soil samples in the fall when it’s dry or diagnostic soil samples in the spring after fertilizer was applied and be surprised by a low soil pH reading. Many of us have. We know salts can depress pH levels. This makes a soil test report difficult to understand and questions the recommendations. Learn how one laboratory is trying to improve on it’s reporting process is this article.

Please contact me if you have questions!


Soil pH Measurement

Below are emails regarding soil pH method change from David H. Hardy, Ph.D. Section Chief- Soil Testing- Agronomic Division, NCDA&CS



I wanted to inform you that our soil testing lab has changed pH measurement to a salt pH method. The change went into effect this past Monday, September 5.

The salt pH reading is a more stable pH in the lab and also will eliminate the effect that varying fluctuations of residual fertilizer salts have on pH.

With this change, the pH reported will be an equivalent water pH that is calculated by adding 0.6 units to the salt pH. On the grower report and also the CSV download, pH will remain as the heading. Reports and CSV downloads will look the same.

The 0.6 adjustment was estimated from comparing over 6000 samples (across all soil classes) using the water pH method vs the salt pH method. The Ac value which arises from our BpH analysis is unaffected.

Our comparison of lime recommendations as related to this change show that similar lime amounts will be recommended in most cases.

We are preparing an educational pamphlet that will further explain this change in more detail. I hope to have it ready by the end of next week.

I feel confident that this will be an excellent change for our lab and our growers. The University of Georgia and University of Kentucky made this change a few years ago with great success.

If you have questions or concerns, please let me know.

Best regards,




Lab Update from Dr. Hardy



Turnaround time is posted as 2 weeks.

In looking at soil reports coming through the lab, they are getting published in about 6 working days. If you see a report that is not released when you think it should be, please call or email us. We are happy to try to get it out to you if possible.

As related to my note about our new salt pH method sent a few weeks ago, I am attaching an educational brochure that I hope will be helpful in understanding and explaining our change. If there are any questions, you can contact me or a regional agronomist. In the near future, we plan to have a limited supply of this bulletin printed for handout.

We still have some white expedited shippers for sale. The price is $200 for 36 samples. These shippers can be used this year or in years to come. We will provide results in 5 to 7 working days if we (Jagathi or myself) are contacted 24 hours in advance of delivery; otherwise, the results are available in 10-working days. These guarantees exclude our Christmas holiday season. You can reserve / purchase shippers by contacting Jagathi by email at Jagathi.Kam@ncagr.gov.

We have added new crops codes- clary sage- 301 and industrial hemp- 310. We hope to have some additional codes related to turf / sod production in the very near future.

If you need supplies, please contact us. Matt Mason is our shipping / receiving coordinator. If you talk to someone at the division, it is always helpful to get a name of who you spoke with.

Right now, the date for the beginning of the peak-fee season has not been scheduled but it can be no later than December 1.

If you have questions or concerns, please let me know.

Thank you for using our services!

Best regards,