|Author: ||M. Tchamitchian|
|Keywords: ||Row Crops, Radiation|
We present a method to determine the intercepted radiation by a greenhouse row crop which takes into account the reflections of light on the side walls.
It is based on a method using shape factors to describe the potential exchanges of radiation between the cells defined in the canopy, the soil and the walls.
This method accounts for multiple scattering in a simple way.
Results of this model are compared to those of a more classical model, already tested on a greenhouse row crop, based on the same method but assuming that the horizontal dimensions of the crop are infinite.
Differences observed are very little, bigger under an overcast sky than under clear conditions.
The influence of the reflectance of the wall can only be seen on the very border of the side rows.
The differences between this model and the classical one are equivalent to variations of the intercepted irradiance observed when the incident irradiance varies by 5%. Given the accurateness of the measurements of the incident irradiance in greenhouses and the difficulty to define a relevant value, we can neglect the influence of the side walls of the greenhouse.
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