ISHS Acta Horticulturae 294: II Symposium on Horticultural Substrates and their Analysis, XXIII IHC
REFERENCE METHOD FOR PHYSICAL AND CHEMICAL CHARACTERIZATION OF GROWING MEDIA : AN INTERNATIONAL COMPARATIVE STUDY |
| Authors: | R. Gabriëls, W. Van Keirsbulck, O. Verdonck |
| Abstract:
By establishing a reference method, used by all laboratories, we will have a way not only for expressing the results on a common basis but also for evaluating the quality criteria of growing media. This paper describes laboratory intercomparison runs with 6 substrates which are tested troughout Europe using more or less identical equipment and methods for determining physical and chemical characteristics. Pine litter, bark and peat based substrates, originating from Belgium, France, Germany, England. The Netherlands and Sweden were sent to 31 laboratories in 15 countries. Physical analysis consisted of the determination of bulk density, total pore space, % moisture on wet and dry weight basis, air and water volume %, at -10, -50 and -100 cm suction respectively. Chemical analysis consisted of the determination of pH-H2O (1:2 vol/vol); E.C., N, P, K, Ca, Mg, SO4, Na, Cl, B (H2O extraction at pF 1) and P, K, Ca, Mg, Na, Zn, Fe, Cu, Mn, Mo (0.5 m buffered ammonium acetate pH 4.65, 1:5 vol/vol). Based on bulk density, all results are expressed in mg per liter substrate. Results of physical characteristics generally came up to expectations. Chemical results however are not yet corresponding, showing higher variability. | |
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