F.J. Sikora, G. Cardon, and B. Thyssen
The North American Proficiency Testing (NAPT) program, directed by the Soil Science Society of America (SSSA), was developed to allow soil test laboratories to evaluate results from their analyses with results from other laboratories. The data gathered over the years has resulted in a rich set of data that can facilitate method comparisons, research, and teaching. A database was developed for quick and easy access to the NAPT data.
The data is available in an Access or Excel file. You need at least Microsoft Access 2002 or Microsoft Excel 2002 to open the files. Click on the desired link above and save the file to your computer. Once saved, double-click on the saved file to open.