Baby greens are becoming increasingly popular in the consumer market because of their desired flavor and leaf size. The short life cycles and fast response times to environmental stimuli make baby greens ideal for testing environmental conditions for Earth- and space-based controlled-environment crop production. Additionally, far-red light has been used in microgreen and baby green research to enhance stem elongation, leaf expansion, and biomass; however, how it interacts with nutrient solution nitrogen concentrations remains unclear. During a ground-based study, we characterized how far-red light and nitrogen concentrations influenced the growth and morphology of Chinese cabbage (Brassica rapa var. chinensis cv. Tokyo Bekana) and kale (Brassica oleracea var. sabellica cv. Red Russian) baby greens under continuous light and similar elevated CO2 and low relative humidity to levels observed in spaceflight.
Key Findings:
Far-red Light: Far-red light is often overlooked in traditional horticultural practices, although recent research suggests that far-red light can promote plant growth when added to blue and red light. When the total light intensity was fixed, partially substituting red light with far-red light increased stem elongation and leaf length but had little influence on plant growth in the baby greens under the test conditions.
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Nitrogen Concentration: Varying nitrogen levels concentrations elicited diverse responses among the baby greens. While some cropsChinese cabbage thrived with higher nitrogen concentrations, others lower nitrogen concentrations were sufficient for showed optimal growth of kaleat lower levels, indicating the necessity for crop-specific nutrient management.
The findings from this study hold significant implications for the future of indoor and urban farming. By fine-tuning light spectra and nutrient concentrations, growers can tailor their practices to meet the specific needs of different crops, leading to enhanced productivity and sustainability.
According to Dr. Meng "This research was performed to address a knowledge gap in light and nutrient management to facilitate efficient production of leafy greens in controlled environments."
Dr. Qingwu Meng, is Assistant Professor of Controlled-Environment Horticulture and Urban Agriculture in the Department of Plant and Soil Sciences at the University of Delaware.
