Effects of freezing on the physical properties and wettability of highly decomposed peats used as growing media

摘要

The influence of freezing on Sphagnum highly decomposed peats was estimated from their physical properties and their wettability measured in relation to the degree of desiccation. The results showed that the physical properties of peats were drastically affected by freezing, particularly improving their water availability and resulting in less, and more reversible, shrinkage after air-drying. However, contact angles measured for frozen or unfrozen peats are very similar. These results seem to indicate that the changes in physical properties are only due to a change in peat structure during freezing and are not a consequence of a change in water affinity. Nevertheless, even if freezing does not affect the wettability of materials, its influence on peat structure contributes to an improvement in their hydric properties.