Short answer

Designers of controlled environment agriculture systems should consider incorporating tunable LED lighting that allows for precise spectral adjustments to optimize microgreen quality and yield, and explore supplemental nighttime lighting for enhanced harvestability.

Field: Resource Management
Source: The Atrium (University of Guelph) (2020)
Method: Experimental research
Evidence: Strong effect

Tailoring the spectral composition of LED lighting can significantly improve the yield, nutritional content, and aesthetic appeal of microgreens in controlled agricultural environments. This resource management research insight is drawn from a 2020 study published in The Atrium (University of Guelph). Using Experimental research, researchers explored how this design variable affects real-world outcomes. The key design takeaway: Designers of controlled environment agriculture systems should consider incorporating tunable LED lighting that allows for precise spectral adjustments to optimize microgreen quality and yield, and explore supplemental nighttime lighting for enhanced harvestability.

Study

Resource ManagementHigh ImpactStrong effect

Optimizing LED Spectra for Microgreen Production Enhances Yield and Nutritional Quality

Tailoring the spectral composition of LED lighting can significantly improve the yield, nutritional content, and aesthetic appeal of microgreens in controlled agricultural environments.

The Atrium (University of Guelph) · 2020

Key Findings

01Varying blue-to-red light ratios did not significantly affect fresh weight, dry weight, total chlorophyll, carotenoid, or nitrate content across most species.
02Increased blue light percentage led to decreased hypocotyl length and cotyledon area in kale and mustard, and a more intense green hue in all species.
03Higher blue light percentages elevated ascorbate, total phenolic, and total anthocyanin levels, indicating improved nutritional and antioxidant properties.
04Supplemental nighttime blue light, with or without far-red light, effectively promoted stem elongation without negatively impacting visual quality or yield, facilitating machine harvesting.

Application

Design takeaway

How to apply

When designing lighting for indoor farms or vertical farms, specify LED fixtures with adjustable spectral outputs. Conduct trials with specific microgreen varieties to determine optimal blue-to-red ratios and nighttime lighting protocols for desired outcomes.

Project actions

01When designing a controlled environment for plant growth, consider how different light colors (wavelengths) affect the plants.
02Experiment with different combinations of red and blue light to see how they influence plant height, leaf size, and color.

Method & Evidence

AimTo investigate the impact of varying ratios of blue and red LED light, as well as supplemental nighttime lighting, on the growth, yield, quality, and phytochemical content of four Brassicaceae microgreen species.

MethodExperimental research

ProcedureMicrogreens were cultivated under different blue-to-red LED light ratios. Hypocotyl length, cotyledon area, fresh weight, dry weight, and various phytochemicals (chlorophyll, carotenoids, nitrates, ascorbate, phenolics, anthocyanins) were measured. Supplemental nighttime blue and far-red light treatments were also evaluated for their effect on stem elongation.

ContextControlled environment agriculture (CEA), indoor farming, microgreen cultivation

Variables

IV["Ratio of blue to red LED light","Presence and type of supplemental nighttime lighting"]

DV["Fresh weight","Dry weight","Hypocotyl length","Cotyledon area","Hue angle (color)","Total chlorophyll","Carotenoid content","Nitrate content","Ascorbate content","Total phenolic content","Total anthocyanin content"]

CV["Photosynthetic photon flux density (PPFD)","Photoperiod","Microgreen species","Growth medium","Temperature","Humidity"]

Strengths & Limitations

Strengths

+Investigated multiple species, providing broader applicability.
+Examined both spectral composition and supplemental lighting strategies.
+Assessed a range of growth and quality parameters.

Limitations

It can be difficult to precisely control light spectrum without specialized equipment. Testing different light combinations can be time-consuming and require multiple growing cycles.

Reliability & validity

The study's validity is supported by the controlled experimental design and the measurement of multiple plant parameters. Reliability would be enhanced by replication of experiments and statistical analysis of results.

Think critically

How might the optimal light spectrum for microgreens differ based on their intended use (e.g., for salads versus for juicing)?

Design Principles

"Light spectrum is a critical design parameter for optimizing plant growth and biochemical composition in controlled environments."

This research demonstrates that precise control over light spectrum is a powerful tool for optimizing crop production. By understanding how different wavelengths influence plant development and biochemistry, designers can develop more efficient and effective controlled environment agriculture (CEA) systems, leading to higher quality produce and potentially reduced resource inputs.

What This Means for Your Design

Changing the color of light used for growing microgreens can make them more nutritious and look better. Adding a little bit of light at night can make them grow taller, which helps when you need to harvest them with machines.

How to use in your project

1.Use this research to justify your choice of lighting spectrum in your design project, explaining how it will optimize plant growth and quality.

Add to My Project

Quick Cite

Paragraph starter

This research highlights the significant impact of light spectral quality on microgreen development. By adjusting the ratio of blue to red light, designers can influence phytochemical content and visual appeal. Furthermore, supplemental nighttime lighting offers a strategy to enhance stem elongation, which is crucial for automated harvesting processes, without compromising overall yield or quality.

Source

The Atrium (University of Guelph)

Exploration on Using Light-Emitting Diode Spectra to Improve the Quality and Yield of Microgreens in Controlled Environments

journal · 2020

View source

Questions About This Research

What does the research say about optimizing led spectra for microgreen production enhances yield and nutritional quality?: Designers of controlled environment agriculture systems should consider incorporating tunable LED lighting that allows for precise spectral adjustments to optimize microgreen quality and yield, and explore supplemental nighttime lighting for enhanced harvestability. Evidence: The Atrium (University of Guelph) (2020).
Why does "Optimizing LED Spectra for Microgreen Production Enhances Yield and Nutritional Quality" matter for design?: This research demonstrates that precise control over light spectrum is a powerful tool for optimizing crop production. By understanding how different wavelengths influence plant development and biochemistry, designers can develop more efficient and effective controlled environment agriculture (CEA) systems, leading to higher quality produce and potentially reduced resource inputs.
How can designers apply this research?: Designers of controlled environment agriculture systems should consider incorporating tunable LED lighting that allows for precise spectral adjustments to optimize microgreen quality and yield, and explore supplemental nighttime lighting for enhanced harvestability.
What were the main findings?: Varying blue-to-red light ratios did not significantly affect fresh weight, dry weight, total chlorophyll, carotenoid, or nitrate content across most species.. Increased blue light percentage led to decreased hypocotyl length and cotyledon area in kale and mustard, and a more intense green hue in all species.. Higher blue light percentages elevated ascorbate, total phenolic, and total anthocyanin levels, indicating improved nutritional and antioxidant properties.. Supplemental nighttime blue light, with or without far-red light, effectively promoted stem elongation without negatively impacting visual quality or yield, facilitating machine harvesting.
What research method was used?: Experimental research.
How strong is the evidence?: Evidence strength is rated Strong effect, based on a 2020 journal from The Atrium (University of Guelph).
What should I do differently in my next project?: When designing lighting for indoor farms or vertical farms, specify LED fixtures with adjustable spectral outputs. Conduct trials with specific microgreen varieties to determine optimal blue-to-red ratios and nighttime lighting protocols for desired outcomes.
What are the limitations?: The study focused on four specific Brassicaceae species; results may vary for other plant types. The long-term effects of spectral manipulation were not assessed. The economic viability of specific spectral recipes was not evaluated.