Effect of the wall temperature

The studies carried out concern either the the behaviour of the crop in the grow chamber compared with the field conditions or the development of measurement instruments.

The walls of the chambers are at the same temperature as the air inside the room.  The thermal radiation which emanate from those wall could thus be different than the thermal radiation received outside from the sky.  Researches based on models showed that this could induce ripening of the crop a week earlier into the crop grow chamber.  Also there is usually no wind in the crop grow chamber.  The boundary layer could be different from outside.  Researches based on the same models showed that during seasons with dry meteorological conditions the effect on the crop parameter could be important.

Effect of the lysimeter wall heat transfer

The lysimeters are thermally isolated from hall where they are standing.  But the soil vertical heat transfer at around one meter depth is low and however small the horizontal transfer could be reduced, it will affect the soil temperature.  A 3D model of heat transfer showed that maximum temperature differences between in place soil and soil in the lysimeter would be at around mid depth and on the side of the lysimeter and could reach 2°C.

Présentation PPT environnement is life

3D model used for the evaluation of the soil heat transfers

Présentation1 PPT environnement is life

Temperature difference between in place soil and soil in the lysimeter

LAI

The crop grow area in the lysimeter is around 2,1 m².  Frequent destructive sampling of plants is thus not permitted and  non destructive plant measurement have been design.  The first one concern the plant canopy geometry and could compute index such as the leaf area index or the mean leaf angle.  Because of the lighting geometry, quite different from outside conditions, tools such as septometers should at least be re-calibrated for a use in an Ecotron.  The proposed method is based on stereoscopic cameras.

Multispectral imaging

This tool is design to acquire up to twenty two images each in a different wavelength band of the canopy.  The aim is to assess the health and grow status of the plant (chlorophyll content, nitrogen content, chloroses, …)