Regional Methods

• Western States (WERA-103)
• Northeastern States (NECC-1812) Formerly NEC-1012
• North Central States (NCERA-13)
• Southern States (SERA-6)

Soil Health Methods

• USDA-NRCS Technical Note 450.03 
• Ammonium-N after Incubation and Extraction
• Anaerobic PMN Incubation
• USDA-NRCS Soil Quality Indicators - Potentially Mineralizable Nitrogen

NAPT Manuals

• Quality Assurance and Quality Control Manual Recommendations (PDF) - A manual of recommended guidelines for writing and maintaining a laboratory QA/QC manual. Developed by the Soil Science Society of America for soil, plant, and water testing laboratories. Second edition (2022). *Also available as a hardcopy version printed in color on waterproof paper - Contact us at napt@soils.org for more information or place an order here. Participants new to the program receive the waterproof copy as an added benefit.