With the growing global urban population and the emergence of megacities, there is a huge demand for arable land to meet the food demand and reduce malnutrition. Conventional agricultural practices lead to deforestation of the land for crop production and agricultural intensification to produce higher yield per unit area. These activities have been established to have negative impact on the environment thereby causing soil and water pollution . It is important to consider the use of vertical farming technology, which utilizes both horizontal and vertical space, and efficiently uses nutrients, water, and time (off season production with artificial lighting) more effectively to produce higher yield per unit volume of space than the conventional outdoor farming. Microgreens are taken into consideration to be grown under innovative vertical farming technology since they are rich in phytonutrients and they can be harvested in a short period of time. This paper reviews the current growing conditions of microgreens in vertical farming such as crop selection, media, light, nutrient solution, and containers while identifying knowledge gaps. Further, study in this area may lead to improved growing conditions to help solve the global issues and challenges surrounding food security, safety, and resource optimization.
Jowell, A., Zhou, B. and Barry, M. (2017) The Impact of Megacities on Health: Preparing for a Resilient Future. The Lancet Planetary Health, 1, e176-e178. https://doi.org/10.1016/S2542-5196(17)30080-3
Food and Agriculture Organization of the United Nations (2017) The Future of Food and Agriculture: Trends and Challenges. Food and Agriculture Organization of the United Nations, Rome.
Lada, R.R., Maijers, W. and Nieboer, S. (2018) Innovative Indoor Horticultural Systems (IHORT) for the 21st Century. Current Investigation in Agriculture and Current Research, 4, 576-581. https://doi.org/10.32474/CIACR.2018.04.000194
Pinto, E., Almeida, A.A., Aguiar, A.A. and Ferreira, I.M.P.L.V.O. (2015) Comparison between the Mineral Profile and Nitrate Content of Microgreens and Mature Lettuces. Journal of Food Composition and Analysis, 37, 38-43. https://doi.org/10.1016/j.jfca.2014.06.018
Xiao, Z., Lester, G.E., Luo, Y. and Wang, Q. (2012) Assessment of Vitamin and Carotenoid Concentrations of Emerging Food Products: Edible Microgreens. Journal of Agricultural and Food Chemistry, 60, 7644-7651. https://doi.org/10.1021/jf300459b
Specht, K., Siebert, R., Hartmann, I., Freisinger, U.B., Sawicka, M., Werner, A., Thomaier, S., Henckel, D., Walk, H. and Dierich, A. (2014) Urban Agriculture of the Future: An Overview of Sustainability Aspects of Food Production in and on Buildings. Agriculture and Human Values, 31, 33-51. https://doi.org/10.1007/s10460-013-9448-4
Savvas, D. (2003) Hydroponics: A Modern Technology Supporting the Application of Integrated Crop Management in Greenhouse. Journal of Food, Agriculture and Environment, 1, 80-86.
Partridge, S.K. (2003) Automated PH Monitoring System for Integration into Environmental Controllers. 58. https://digitalcommons.wpi.edu/mqp-all/2892
Drewnowski, A. and Gomez-Carneros, C. (2000) Bitter Taste, Phytonutrients, and the Consumer: A Review. The American Journal of Clinical Nutrition, 72, 1424-1435. https://doi.org/10.1093/ajcn/72.6.1424
Treadwell, D.D., Hochmuth, R., Landrum, L. and Laughlin, W. (2010) Microgreens: A New Specialty Crop. University of Florida IFAS Extension HS1164.3.
Muchjajib, U., Muchjajib, S., Suknikom, S. and Butsai, J. (2015) Evaluation of Organic Media Alternatives for the Production of Microgreens in Thailand. Acta Horticulturae, 1102, 157-162. https://doi.org/10.17660/ActaHortic.2015.1102.19
Di Gioia, F., De Bellis, P., Mininni, C., Santamaria, P. and Serio, F. (2017) Physicochemical, Agronomical and Microbiological Evaluation of Alternative Growing Media for the Production of Rapini (Brassica Rapa L.) Microgreens: Recycled Fibrous Materials for Rapini Microgreens Production. Journal of the Science of Food and Agriculture, 97, 1212-1219. https://doi.org/10.1002/jsfa.7852
Singh, D., Basu, C., Meinhardt-Wollweber, M. and Roth, B. (2015) LEDs for Energy Efficient Greenhouse Lighting. Renewable and Sustainable Energy Reviews, 49, 139-147. https://doi.org/10.1016/j.rser.2015.04.117
Nishio, J.N. (2000) Why Are Higher Plants Green? Evolution of the Higher Plant Photosynthetic Pigment Complement. Plant, Cell and Environment, 23, 539-548. https://doi.org/10.1046/j.1365-3040.2000.00563.x
Kim, S.-J., Hahn, E.-J., Heo, J.-W. and Paek, K.-Y. (2004) Effects of LEDs on Net Photosynthetic Rate, Growth and Leaf Stomata of Chrysanthemum Plantlets in Vitro. Scientia Horticulturae, 101, 143-151. https://doi.org/10.1016/j.scienta.2003.10.003
Heo, J.-W., Kang, D.-H., Bang, H.-S., Hong, S.-G., Chun, C.-H. and Kang, K.-K. (2012) Early Growth, Pigmentation, Protein Content, and Phenylalanine Ammonia-Lyase Activity of Red Curled Lettuces Grown under Different Lighting Conditions. Korean Journal of Horticultural Science and Technology, 30, 6-12. https://doi.org/10.7235/hort.2012.11118
Lobiuc, A., Vasilache, V., Oroian, M., Stoleru, T., Burducea, M., Pintilie, O. and Zamfirache, M.-M. (2017) Blue and Red LED Illumination Improves Growth and Bioactive Compounds Contents in Acyanic and Cyanic Ocimum basilicum L. Microgreens. Molecules, 22, 2111. https://doi.org/10.3390/molecules22122111
Muneer, S., Kim, E., Park, J. and Lee, J. (2014) Influence of Green, Red and Blue Light Emitting Diodes on Multiprotein Complex Proteins and Photosynthetic Activity under Different Light Intensities in Lettuce Leaves (Lactuca sativa L.). International Journal of Molecular Sciences, 15, 4657-4670. https://doi.org/10.3390/ijms15034657
Brazaityte, A., Sakalauskiene, S., Samuoliene, G., Jankauskiene, J., Virsile, A., Novickovas, A., Sirtautas, R., Miliauskiene, J., Vastakaite, V., Dabasinskas, L. and Duchovskis, P. (2015) The Effects of LED Illumination Spectra and Intensity on Carotenoid Content in Brassicaceae Microgreens. Food Chemistry, 173, 600-606. https://doi.org/10.1016/j.foodchem.2014.10.077
Virsile, A. and Sirtautas, R. (2013) Light Irradiance Level for Optimal Growth and Nutrient Contents in Borage Microgreens. Proceedings of the International Scientific Conference: Rural Development, Vol. 6, 272.
Poulet, L., Massa, G.D., Morrow, R.C., Bourget, C.M., Wheeler, R.M. and Mitchell, C.A. (2014) Significant Reduction in Energy for Plant-Growth Lighting in Space Using Targeted LED Lighting and Spectral Manipulation. Life Sciences in Space Research, 2, 43-53. https://doi.org/10.1016/j.lssr.2014.06.002
Piovene, C., Orsini, F., Bosi, S., Sanoubar, R., Bregola, V., Dinelli, G. and Gianquinto, G. (2015) Optimal Red: Blue Ratio in Led Lighting for Nutraceutical Indoor Horticulture. Scientia Horticulturae, 193, 202-208. https://doi.org/10.1016/j.scienta.2015.07.015
Hendrey, G.R., Lewin, K.F. and Nagy, J. (1993) Free Air Carbon Dioxide Enrichment: Development, Progress, Results. In: Rozema, J., Lambers, H., Van de Geijn, S.C. and Cambridge, M.L., Eds., CO2 and Biosphere, Springer, Berlin, 17-32. https://doi.org/10.1007/978-94-011-1797-5_2
Ford, M.A. and Thorne, G.N. (1974) Effects of Atmospheric Humidity on Plant Growth. Annals of Botany, 38, 441-452. https://doi.org/10.1093/oxfordjournals.aob.a084827
Hatfield, J.L. and Prueger, J.H. (2015) Temperature Extremes: Effect on Plant Growth and Development. Weather and Climate Extremes, 10, 4-10. https://doi.org/10.1016/j.wace.2015.08.001
Hoagland, D.R. and Dennis, R. (1938) The Water-Culture Method for Growing Plants without Soil.
Steiner, A.A. (1961) A Universal Method for Preparing Nutrient Solutions of a Certain Desired Composition. Plant and Soil, 15, 134-154. https://doi.org/10.1007/BF01347224
Gerovac, J.R., Craver, J.K., Boldt, J.K. and Lopez, R.G. (2016) Light Intensity and Quality from Sole-Source Light-Emitting Diodes Impact Growth, Morphology, and Nutrient Content of Brassica Microgreens. HortScience, 51, 497-503. https://doi.org/10.21273/HORTSCI.51.5.497
Weber, C.F. (2016) Nutrient Content of Cabbage and Lettuce Microgreens Grown on Vermicompost and Hydroponic Growing Pads. Journal of Horticulture, 3, 1-5. https://doi.org/10.4172/2376-0354.1000190
Berba, K.J. and Uchanski, M.E. (2012) Post-Harvest Physiology of Microgreens. Journal of Young Investigators, 24, 5.