TEMPERATURE IN CONTAINER SUBSTRATES
The measurements were made under two different substrates (peat-bark TE, and peat-sand TS). Seven temperature probes were placed in a container, to follow the evolution of the temperature, depending on the depth and the orientation.
Little differences were observed between the substrates : larger thermal amplitude in the centre, light delay of TE curves comparatively to TS curves.
In sunny weather, the differences of temperature observed from one point to another of the substrate volume, are very high (13°C from the centre to the South at 12.00 GMT, with a temperature of 40°C measured on the wall facing West at 16.00 GMT. In a horizontal level, the evolution of the temperature follows the direction of the direct solar radiation.
In cloudy weather, differences were weak.
In a vertical section, the temperature were homogeneous in the morning. The evaporation provokes a temperature lowering on the top.
We conclude that the substrate characteristics are not the most important factors. The evolution of the temperature in substrates seems to be related to the environment factors, especially to radiative energy.