The goal of the North American Proficiency Testing (NAPT) Program is to assist soil, plant and water testing laboratories in their performance through inter-laboratory sample exchanges and a statistical evaluation of the analytical data.

The program guidelines have been developed for the agricultural laboratory industry by representatives from groups familiar with and involved in standardizing methods and developing nutrient recommendations for soil and plant analysis methods within the U.S. and Canada. It is operated as an activity of the Soil Science Society of America and overseen by an oversight committee comprised of representatives of the above-mentioned groups. These include: Regional Soil and Plant Analysis Workgroups; Scientific Organizations; State/Provincial Departments of Agriculture; and private and public and plant analysis labs.

How to Enroll

Enrollment is through the Soil Science Society of America (SSSA). For information on the program, please see our brochure. To enroll, please fill out the enrollment form and send to SSSA. Enrollment Form »

Lab Results Reporting

Forms for participants to submit lab results each quarter are available in MS Excel and PDF formats.


NAPT Program Events Calendar

March 2008 Newsletter

The March 2008 edition of the NAPT Program Newsletter has been released (http://www.naptprogram.org/publications/newsletters/080320.pdf). Through this venue, the NAPT Oversight Committee (S-890) plans to provide you with updates on the program, information on upcoming events, a summary of committee activities and lists of important dates. We hope you find this newsletter helpful and informative. Please let us know if there is anything you would like to see addressed in upcoming issues