ISHS Acta Horticulturae 644: International Symposium on Growing Media and Hydroponics
COMPARISON OF PHYSICAL AND CHEMICAL PROPERTIES OF GROWING MEDIA BASED ON THE EUROPEAN STANDARD METHOD AND THE SELF-COMPACTION METHOD |
| Authors: | H.J. Park, Y.K. Jung, K.-H. Kim, J.E. Son |
| Keywords: | bulk density, moisture retention curve, pH, EC |
| Abstract:
Bulk density is the most important factor in determining physical and chemical properties of growing media since volume is the basis in handling growing media. We compared the bulk densities of various growing media measured by European Standard method and by “self-compaction method” which is a mixture of the Perlite Institute method and ASTM D 4253-93. The bulk densities of the growing media determined by the self-compaction method were similar to those in the actual pots, which were greater than those by the European Standard method. The water holding capacity, pH, and electrical conductivity (EC) were determined based on the bulk densities measured by self-compaction method. The moisture retention curves were evaluated with a tempe cell, sand box and pressure chamber at below 1 bar, and with a centrifuge and pressure chamber at over 1 bar. The moisture retention curves with the tempe cell and sand box at below 1 bar were similar to each other. However, at a specific tension below 1 bar, the water contents with the pressure chamber were greater than those with the tempe cell and sand box. Values at over 1 bar with the pressure chamber were greater than those with the centrifuge. The pH and EC of the growing media measured by the saturated media extract method showed high correlations with those by the 1:2 (v/v) extraction ratio but not by the 1:5 (v/v). | |
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