Ring Tests by Section II Soil Analysis

• A major part of the work performed by this section is the execution of annual ring tests. These tests serve both to develop and to verify new methods for the VDLUFA method book I  "Soil Analysis" and also to review the quality of laboratory analysis conducted by the section.
  
  
• For many years now, statistical parameters from the two ring test matrices agricultural soils and harticultural growing media have been recorded in a table including values such as the mean value, the reproducibility standard deviation, the repeatability standard deviation and the Horwitz ratio. This data made it possible to draw up the Annex E5 to Methods Book I: "Measurement Uncertainties of Parameters for Analytical Testing of Soils and Substrates Derived from Ring Tests" in 2011.