SERA-IEG-6
The Southern Extension and Research Activities Information Exchange Group on soil, plant, water, and waste analysis (SERA-IEG-6) develops, modifies, and documents reference laboratory procedures, "regionalizes" soil test calibration/correlation and interpretation efforts among states that share similar soils and climate, and encourages both analytical proficiency and adequate quality control/quality assurance for nutrient analysis laboratories in the Southern Region of the United States. (From the SERA-IEG-6 website.)