ISHS Acta Horticulturae 697: International Symposium on Soilless Culture and Hydroponics
CONSIDERATIONS ABOUT THE PACKING DENSITY OF GROWING MEDIA PREPARED UNDER INCREASING LEVELS OF HUMIDITY |
| Authors: | H. Fermino, A. Kämpf |
| Keywords: | Brazilian brown peat, void ratio, substrate penetrability |
| Abstract:
The growers are recommended to moisturize growing media prior to fill the pots, to avoid subsidence and consequently the loss of volume, specially after irrigation. This study measures the effect of three procedures to fill containers (without compaction - based on the norm EN 12580; with top compaction – based on the norm EN 13040, and with self compaction, based on the German method after VDLUFA) using samples of a Brazilian brown peat with increasing levels of humidity (62, 69 and 73 % gravimetric humidity), on the following physical properties: amount of packed solids (as dry bulk density), total porosity, void ratio and penetrability. The procedures without and with top compaction applied to very moist samples (73% gravimetric humidity) maintain higher volume of porosity using less substrate. On the other hand, the initial compaction obtained using the method after VDLUFA reduces the subsidence of the potted substrate. Although, the use of this procedure with the highest level of humidity causes higher compaction and consequently reduction of the penetrability of the substrate. | |
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