The interception of the light is calculated by the trees and the culture at the time step
- For the trees it results from the calculation of the thickness of the crown crossed by the rays of the sun at different times of the day and integrated on the day.
- For the culture it follows a law of Beer (f (LAI)) for the homogeneous cutlery. Another option allows the calculation of radiative transfers for row crops.
The conversion of the intercepted light into carbon is then calculated:
- For trees: LUE (light use efficiency) is a fixed parameter per species that is reduced by the effect of water and nitrogen stress.
- For crop: it depends on phenological stage, temperature, intercepted PAR (saturation curve) reduced by water and nitrogen stress