ISHS Acta Horticulturae 548: International Symposium on Growing Media and Hydroponics
STATISTICAL EVALUATION OF THE METHODS STANDARDIZED BY CEN |
| Author: | A. Baumgarten |
| Keywords: | Comité Européen de Normalisation, CEN, Standardisation, water extraction, CAT – extraction, aqua regia extraction, total nitrogen, particle size distribution |
| Abstract:
6 methods for chemical (extraction by aqua regia, CaCl2/DTPA – solution and water; determination of total nitrogen) and physical analysis (particle size distribution) of soil improvers and growing media standardized by the Comité Européen de Normalisation (CEN) were tested for accuracy in an international ring trial. With the exception of the particle size distribution all of the methods and most of the commonly determined parameters tested proved to be sufficiently repeatable and reproducible by a variety of laboratories not trained in performing these methods. The limitations of the methods for determining certain parameters could be shown. The restriction of performance is partly due to the low levels of extractable elements. On the other hand differing determination procedures may also lead to increasing variances. | |
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