Dimming method for constant light intensity

1. A horticulture arrangement for plants, the horticulture arrangement comprising:

a horticulture lighting system comprising one or more lighting devices configured to provide horticulture light;

one or more reflective elements configured to reflect part of the horticulture light to provide reflected horticulture light, where the extent to which the horticulture light is reflected by the one or more reflective elements is expressed by a gain factor, wherein the gain factor is determined using a predetermined gain function; and

a control system, wherein the control system is configured to control one or more of a light intensity and a spectral distribution of the horticulture light,

wherein the control system in configured to control the one or more of the light intensity and the spectral distribution of the horticulture light in dependence on the extent to which the horticulture light is reflected by the one or more reflective elements, and wherein the control system is configured to control one or more of the light intensity and the spectral distribution of the horticulture light in an inverse proportional relationship with the gain factor.

2. The horticulture arrangement according to claim 1 , wherein at least part of the reflected horticulture light is directed in the direction of the one or more lighting devices, wherein one or more first reflective elements are configured to reflect at least a part of the reflected horticulture light directed in the direction of the one or more lighting devices back to the plants.

3. The horticulture arrangement according to claim 1 , comprising a structure for hosting the plants, wherein the structure comprises plant positions where the plants can be positioned, and intermediate parts between the plant positions, wherein one or more intermediate parts comprise one or more second reflective elements.

4. The horticulture arrangement according to claim 1 , wherein the control system is configured to control the horticulture light according to a predefined light recipe, wherein the light recipe includes information on one or more of (i) intensity of the horticulture light as function of time, and (ii) spectral distribution of the horticulture light as function of time, whereby the light recipe defines one or more of a target light intensity and spectral distribution of the horticulture light, and wherein the control system is further configured to control one or more of the light intensity and spectral distribution of the horticulture light in dependence on one or more of the target light intensity and spectral distribution of the horticulture light and the extent to which the horticulture light is reflected by the one or more reflective elements.

5. The horticulture arrangement according to claim 1 , wherein the control system is configured to control the intensity of the horticulture light according to a light recipe with a target intensity of the horticulture light, and wherein the control system is configured to adapt the horticulture light intensity of the horticulture light according to the light recipe on the basis of a predetermined relation between light intensity in μmol/s/m 2 provided by the horticulture lighting system and light intensity effectively received by the plants.

6. The horticulture arrangement according to claim 1 , comprising one or more optical sensors configured to sense reflected horticulture light and to generate one or more corresponding optical sensor signals, wherein the one or more optical sensors comprise sensor surfaces, wherein the sensor surfaces are configured to receive no direct horticulture light, and

wherein the horticulture arrangement is configured for growth of plants in a growth medium, wherein one or more lighting devices are arranged above the growth medium at a lighting device height of from the growth medium, and wherein one or more first optical sensors are arranged at a sensor height selected from the range of 0-40% of the lighting device height, and wherein the one or more first optical sensors are configured with sensor surfaces directed upwards.

7. The horticulture arrangement according to claim 6 , wherein the horticulture arrangement is configured for growth of plants in a growth medium, wherein one or more lighting devices are arranged above the growth medium at a lighting device height of from the growth medium, and wherein one or more second optical sensors are arranged at a sensor height selected from the range of 50-150% of the lighting device height, wherein the one or more second optical sensors are configured with sensor surfaces directed downwards.

8. A horticulture arrangement for plants, the horticulture arrangement comprising:

a horticulture lighting system comprising one or more lighting devices configured to provide horticulture light;

one or more reflective elements configured to reflect part of the horticulture light to provide reflected horticulture light; and

a control system, wherein the control system is configured to control one or more of a light intensity and a spectral distribution of the horticulture light,

wherein the control system in configured to control the one or more of the light intensity and the spectral distribution of the horticulture light in dependence on the extent to which the horticulture light is reflected by the one or more reflective elements, and

one or more optical sensors configured to sense reflected horticulture light and to generate one or more corresponding optical sensor signals and wherein the extent to which the horticulture light is reflected by the one or more reflective elements is expressed by a gain factor determined using the one or more corresponding optical sensor signals, and wherein the control system is configured to control one or more of the light intensity and the spectral distribution of the horticulture light in an inverse proportional relationship with the gain factor.

9. The horticulture arrangement according to claim 8 , wherein the one or more optical sensors comprise sensor surfaces, wherein the sensor surfaces are configured to receive no direct horticulture light.

10. The horticulture arrangement according to claim 8 , wherein the horticulture arrangement is configured for growth of plants in a growth medium, wherein one or more lighting devices are arranged above the growth medium at a lighting device height of from the growth medium, and wherein one or more first optical sensors are arranged at a sensor height selected from the range of 0-40% of the lighting device height, and wherein the one or more first optical sensors are configured with sensor surfaces directed upwards.

11. The horticulture arrangement according to claim 8 , wherein the horticulture arrangement is configured for growth of plants in a growth medium, wherein one or more lighting devices are arranged above the growth medium at a lighting device height of from the growth medium, and wherein one or more second optical sensors are arranged at a sensor height selected from the range of 50-150% of the lighting device height, wherein the one or more second optical sensors are configured with sensor surfaces directed downwards.

12. The horticulture arrangement according to claim 8 , wherein at least part of the reflected horticulture light is directed in the direction of the one or more lighting devices, wherein one or more first reflective elements are configured to reflect at least a part of the reflected horticulture light directed in the direction of the one or more lighting devices back to the plants.

13. The horticulture arrangement according to claim 8 , comprising a structure for hosting the plants, wherein the structure comprises plant positions where the plants can be positioned, and intermediate parts between the plant positions, wherein one or more intermediate parts comprise one or more second reflective elements.

14. The horticulture arrangement according to claim 8 , wherein the control system is configured to control the horticulture light according to a predefined light recipe, wherein the light recipe includes information on one or more of (i) intensity of the horticulture light as function of time, and (ii) spectral distribution of the horticulture light as function of time, whereby the light recipe defines one or more of a target light intensity and spectral distribution of the horticulture light, and wherein the control system is further configured to control one or more of the light intensity and spectral distribution of the horticulture light in dependence on one or more of the target light intensity and spectral distribution of the horticulture light and the extent to which the horticulture light is reflected by the one or more reflective elements.

15. A method of providing horticulture light to plants in a horticulture arrangement comprising one or more reflective elements configured to reflect part of the horticulture light to provide reflected horticulture light, the method comprising providing the horticulture light to the plants and controlling one or more of a light intensity and a spectral distribution of the horticulture light, and

wherein controlling the one or more of the light intensity and the spectral distribution of the horticulture light in dependence on the extent to which the horticulture light is reflected by the one or more reflective elements, and where the extent to which the horticulture light is reflected by the one or more reflective elements is expressed by a gain factor, wherein the gain factor is determined using a predetermined gain function, and wherein the control system is configured to control one or more of the light intensity and the spectral distribution of the horticulture light in an inverse proportional relationship with the gain factor.

16. The method according to claim 15 , the method comprising controlling the horticulture light according to a predefined light recipe, wherein the light recipe includes information on one or more of (i) intensity of the horticulture light as function of time, and (ii) spectral distribution of the horticulture light as function of time, whereby the light recipe defines a target horticulture light intensity, and controlling the one or more of the light intensity and spectral distribution of the horticulture light in dependence on the target horticulture light intensity the extent to which the horticulture light is reflected by the one or more reflective elements.

17. The method according to claim 15 , wherein at least part of the reflected horticulture light is directed in the direction of the one or more lighting devices, wherein one or more first reflective elements are configured to reflect at least a part of the reflected horticulture light directed in the direction of the one or more lighting devices back to the plants.

18. The method according to claim 15 , wherein the horticulture arrangement comprises a structure for hosting the plants, wherein the structure comprises plant positions where the plants can be positioned, and intermediate parts between the plant positions, wherein one or more intermediate parts comprise one or more second reflective elements.

19. The method according to claim 15 , wherein the horticulture arrangement comprises one or more optical sensors configured to sense reflected horticulture light and to generate one or more corresponding optical sensor signals, wherein the one or more optical sensors comprise sensor surfaces, wherein the sensor surfaces are configured to receive no direct horticulture light, and

wherein the horticulture arrangement is configured for growth of plants in a growth medium, wherein one or more lighting devices are arranged above the growth medium at a lighting device height of from the growth medium, and wherein one or more first optical sensors are arranged at a sensor height selected from the range of 0-40% of the lighting device height, and wherein the one or more first optical sensors are configured with sensor surfaces directed upwards, and

wherein the horticulture arrangement is configured for growth of plants in a growth medium, wherein one or more lighting devices are arranged above the growth medium at a lighting device height of from the growth medium, and wherein one or more second optical sensors are arranged at a sensor height selected from the range of 50-150% of the lighting device height, wherein the one or more second optical sensors are configured with sensor surfaces directed downwards.

20. A non-transitory computer readable medium having stored thereon software instructions that, when executed by a processor, perform the method of claim 15 .