Vertical farming has been heralded as the future of modern agronomy. There is a growing amount of investment in vertical farming by big firms, which is a good step moving forward. Investments have been made towards indoor spaces, planting panels, and grow lights.
With regard to grow lights, they have become a prerequisite for crop production in vertical farming. In the absence of natural light, the gamut or spectrum (quality of light) in vertical farming is heightened to the highest degree.
In vertical farming, the light intensity is very high compared to other indoor light usage purposes. This massive light intensity means the facilities in which these crops are planted in need to be cooled. However, cooling creates a very substantial thermal load for farmers.
For this reason, farmers will tend to go for LED lights in vertical farming. LED bulbs produce a lot of light, and they are very energy efficient. This means these bulbs require no cooling, and this lowers the overall cost of production for indoor farmers.
What Are Grow Lights in Vertical Farming?
A grow light is a synthetic source of light, mostly electric, designed to fuel the growth of crops by producing an electromagnetic spectrum ideal for photosynthesis. Grow lights are used in situations where no sunlight cannot be used or where extra light is needed.
For instance, during winter, grow lights can be used as an auxiliary source of light to enhance crop growth. In indoor farming, grow lights can completely replace the essence of sunlight. The lights come into variants, namely vertical grow lights and horizontal grow lights.
By deploying grow lights in your indoor farming space, you are effectively trying to outmaneuver mother nature and create the precise conditions for your crops to bloom. Thus, rather than conforming to meager cultivation conditions, you can create an optimum development environment that you alone control.
Grow lights, however, can’t always replicate direct sunlight, but in some applications, they can outperform the effect of the sun. There are numerous reasons why farmers adopt grow lighting technology in indoor farms, and they include:
- Indoor crop cultivation such as flowers, houseplants, fruits, and vegetables.
- Preparing seedlings for spring.
- Crop propagation.
- Extending daylight hours for crops that need long and hot days to reach their peak.
- Extending the growing season for crops grown in areas where it gets cold quickly.
Which Light Spectrums Are Required in Vertical Farming?
Light sourced from the blue and purple end of the color spectrum is considered cool and ideal for crops in their vegetative phase. You can use cool light for formative seedlings to grow outdoors during spring or to propagate roots from other crops.
Once your seeds have germinated, the cool light will inspire controlled but healthy development of the roots and greenery of your crops. Cool lighting is also ideal for non-flowering houseplants.
Orange-red light is regarded to as warm light. This is used to stimulate the growth of fruits and flowers. Once your crops have developed to full maturity, you can change the light from cool to warm to force the crops to flower and inspire more flowering and eventually more fruit.
For instance, tomatoes need warm light to grow well. However, warm light is capable of producing elongated, thin stalks with marginal greenery, which hinders the crops’ capacity to produce food. Therefore, it shouldn’t be used too soon.
In light bulbs, the warmth to coolness scale is 2700k to 4000k. The larger the scale, the cooler the light; crops need warm light to blossom and cool light to produce greenery. You can find light bulbs that can produce both of these light spectrums. However, using separate lights for each color spectrum is likely to produce the best results.
What Is the Appropriate Light Schedule for Your Crops?
Similar to all living things, plants function with a cycle of day and night in the environment. Although using grow lights can let you provide 24 hours of lighting, it’s not appropriate for your crops. Ideally, lighting should be timed to match the number of sun hours on a normal day.
Basically, you should set a target that your crops receive about 12 hours of light. This is because crops require just eight hours of the night to restructure and thus produce flowers. Similar to the human sleeping period, during the night is when crops get to be revitalized.
If managing these conditions is somewhat challenging, you could always configure the lighting framework to be on a timer. This will ensure that your crops always have constant light, which is vital for the crops maintaining optimum growth
How Do You Space Your Lighting Bars?
Various types of light bulbs require different spacing from your crops because of the level of heat they produce. Therefore, it’s advisable to place the source of light directly above the crops to simulate noon. Your crops’ needs will dictate the precise placement of the light sources.
If your crops are exposed to too much heat or the light is too direct, the leaves will develop burn marks that can cause stunted growth or death of your crops. If you detect that your crops are struggling, you should change the placement of the light source to correct it.
Light bulbs suspended from a flexible cable are perfect because they can be lowered or lifted as the crops develop. Some of the placements for different light bulbs include:
- Fluorescent bulbs should be placed between 3 and 12 inches from your crops.
- LEDs should be placed between 12 to 14 inches from the crops.
- HID bulbs should be placed between 24 to 60 inches from the crops.
To sum it all up, there are many decisions to make when it comes to lighting in your vertical farm. However, as illustrated above, you should pick lights with the ideal light intensity and spectrum to ensure that your crops bloom well and in the right conditions.