The Virginia Tech Soil Testing Laboratory participates in the North American Proficiency Testing (NAPT) program, http://www.naptprogram.org/, which assists agricultural labs in their performance through inter-laboratory sample exchanges and statistical evaluations of the analytical data.
The Soil Testing Laboratory uses an Inductively Coupled Plasma Atomic Emission Spectrometer for analyzing the nutrient content of soil extracts. A description of ICP analysis is here.
