Recommended Chemical Soil Test Procedures for the North Central Region

Editor's note
The following abstract describes a publication that is intended for print distribution or as a downloadable PDF. Please see links to the PDF file and ordering information on this page.
Following printing in January 1998, errors were discovered on pages 26 and 56 and corrected on the PDF file. Some printed copies were corrected with stickers. An error on page 24 of the PDF was discovered and
corrected in February 2011. This error was not in the printed version.

This publication is a revision of North Central Regional Research Publication No. 221 (NCR221).

For more than a century, soil and plant scientists have been developing methods for determining the levels of plant-available nutrients in soils.

Over the past 30 years, the NCR-13 Soil Testing and Plant Analysis committee members have worked hard at standardizing the procedures of soil testing laboratories with which they are associated. As a result of these activities, the committee arrived at the recommended procedures for soil tests.


  • Soil sample preparation
  • Standard soil scoop
  • Soil extraction
  • pH
  • Lime requirements
  • Nitrate-nitrogen
  • Phosphorus
  • Potassium
  • Cations
  • Sulfate-sulfur
  • Micronutrients
  • Zinc
  • Iron
  • Manganese
  • Copper
  • Boron
  • Chlorides
  • Soil organic matter
  • Soil salinity
  • Greenhouse root media
  • Laboratory quality assurance program


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