Light source for plant cultivation and method of plant cultivation using thereof
A light source for plant cultivation includes a first light source emitting a first type of light for photosynthesis of a plant and a second light source emitting a second type of light for adjustment of phytochemicals in the plant. The first type of light has at least one peak in the visible spectrum, and the second type of light has a peak in a different wavelength band from the first light source. The second type of light has a peak in the wavelength band of about 360 nm to about 420 nm.
1. A light source for plant cultivation adapted to emit light to a plant, the light source comprising:
a first light source configured to emit a first type of light for photosynthesis of the plant, the first type of light having at least two peaks in the visible spectrum; and
a second light source, the second light source being a phytochemical adjustment light source that is configured to emit a second type of light for adjustment of phytochemicals in the plant, the second type of light having a third peak in a different wavelength band from the at least two peaks of the first type of light,
a controller configured to control the first light source and the second light source such that
the third peak of the phytochemical adjustment light source is in the wavelength band of 360 nm to 420 nm,
an intensity of the first type of light at a first peak is consistently less than half the intensity of the phytochemical adjustment light source at the third peak,
the third peak is a highest peak of the second type of light, and
in the first peak is a second highest peak of the first type of light and is in the wavelength band of 420 nm to 500 nm.
2. The light source for plant cultivation according to claim 1 , wherein the second type of light is ultraviolet light, purple light or blue light.
3. The light source for plant cultivation according to claim 2 , wherein the second type of light has a peak in the wavelength band of 400 nm to 420 nm.
4. The light source for plant cultivation according to claim 1 , wherein the at least two peaks of the first type of light are in the wavelength band of −400 nm to 700 nm.
5. The light source for plant cultivation according to claim 1 , wherein the first type of light corresponds to PAR (Photosynthetic Active Radiation).
6. The light source for plant cultivation according to claim 1 , wherein the first light source emits light having a spectrum that spans the visible wavelength band.
7. The light source for plant cultivation according to claim 1 , wherein an intensity of the first type of light at a second peak is consistently substantially the same as an intensity of the second type of light, wherein the second peak is in the wavelength band of 600 nm to 700 nm.
8. The light source for plant cultivation according to claim 1 , wherein the first light source and the second light source are independently driven to be turned on or off.
9. The light source for plant cultivation according to claim 8 , wherein each of the first light source and the second light source comprises:
a first semiconductor layer doped with a first conductivity type dopant;
a second semiconductor layer disposed on the first semiconductor layer and doped with a second conductivity type dopant different from the first conductivity type dopant; and
an active layer interposed between the first semiconductor layer and the second semiconductor layer.
10. The light source for plant cultivation according to claim 1 , wherein the first light source is turned on or off according to a photo-period consisting of a light period and a dark period.
11. The light source for plant cultivation according to claim 10 , wherein the second type of light is emitted for a period of time at least partially overlapping the light period and the dark period.
12. The light source for plant cultivation according to claim 11 , wherein the second type of light is continuously emitted.
13. The light source for plant cultivation according to claim 1 , wherein the phytochemicals comprise at least one selected from among phenolic and antioxidant substances.
14. The light source for plant cultivation according to claim 1 , wherein the plant is a cruciferous plant.
15. The light source for plant cultivation according to claim 14 , wherein the cruciferous plant comprises at least one selected from among kale, broccoli, cabbage, Chinese cabbage, shepherd's purse, bok choy, oilseed rape, radish, and mustard.
16. A plant cultivation method using a light source for plant cultivation adapted to emit light to a plant, the light source for plant cultivation comprising:
a first light source emitting a first type of light for photosynthesis of the plant, the first type of light having at least two peaks in the visible spectrum; and
a second light source, the second light source being a phytochemical adjustment light source emitting a second type of light for adjustment of phytochemicals in the plant, the second type of light having a third peak in a different wavelength band from the at least two peaks of the first type of light,
wherein the third peak of the phytochemical adjustment light source is in the wavelength band of 360 nm to 420 nm, an intensity of the first type of light at a first peak is consistently less than half the intensity of the phytochemical adjustment light source at the third peak, wherein the third peak is a highest peak of the second type of light, and wherein the first peak is a second highest peak of the first type of light and is in the wavelength band of 420 nm to 500 nm, and the content of phytochemicals in the plant is adjusted by irradiating the plant with the first type of light and the second type of light.
17. The plant cultivation method according to claim 16 , wherein the second type of light has a peak in the wavelength band of 400 nm to 420 nm.
18. The plant cultivation method according to claim 17 , wherein the first type of light has at least two peaks in the wavelength band of 380 nm to 780 nm and corresponds to PAR (Photosynthetic Active Radiation).
19. The plant cultivation method according to claim 16 , wherein the first light source is turned on or off according to a photo-period consisting of a light period and a dark period.
20. The plant cultivation method according to claim 19 , wherein the second type of light is emitted for a period of time at least partially overlapping the light period and the dark period.