Get in touch
Questions about growing, workshops, the cooperative or partnerships? Send us a message and we will reply by email.
Prefer email? Write to erasmus@evec.org.gr
EVEC Microgreens
Substrate Effects on Yield and Nutritional Quality of Amaranth Microgreens in Floating-Tray Hydroponics
Floating-tray hydroponics is expanding for microgreen production, yet evidence on substrate performance under natural-light greenhouses remains limited. Th
Gilda Carrasco, Pabla Rebolledo, Fernando Fuentes-Peñailillo, Rolón Gómez, Paula Manríquez
Horticulturae · 2025 · https://doi.org/10.3390/horticulturae11111395
Abstract
Floating-tray hydroponics is expanding for microgreen production, yet evidence on substrate performance under natural-light greenhouses remains limited. This study compared perlite, coconut coir, and a 1:1 (v/v) perlite–coconut coir mixture for amaranth (Amaranthus cv. ‘Diablo Rojo’) grown at the end of summer in an unheated greenhouse (CRD; 4 replicates). Perlite significantly improved establishment and yield: emergence reached 72.6% versus 46.1% in coconut coir and 35.1% in the mixture, with fresh biomass of 297, 171, and 119 g m−2, respectively. The proximate composition exhibited consistency across substrates (protein ≈ 32% DW; crude fiber ≈ 32% DW; crude fat ≈ 2.5% DW), whereas nitrate concentrations varied between 1300 and 2500 mg kg−1 FW, irrespective of the substrate. Vitamin C and total phenolics showed no significant variation, and β-carotene exhibited only a slight, non-significant increase in coconut coir. In contrast, mineral composition was substrate-dependent: perlite increased Ca (3626 ppm DW) and Mg (1094 ppm DW), while P and Fe were unaffected; Na was higher in perlite. These results indicate that under natural-light, unheated greenhouses, bioactive compounds are mainly influenced by environmental variability, whereas root-zone aeration drives Ca/Mg enrichment and yield. Perlite-based floating-tray systems represent efficient, low-cost strategies with potentially lower environmental impact, suitable for scalable urban and smallholder microgreen production. These findings, derived from a single-season trial in one unheated greenhouse, should be regarded as preliminary yet consistent with previous studies on microgreens. Future multi-season and multi-species experiments will help to confirm and expand on these results.
Licence and reuse
| Licence | CC-BY-4.0 |
|---|---|
| May we host this PDF? | Yes |
| May we publish a plain-language summary? | Yes — this licence permits adaptations. |
| Commercial use permitted? | Yes |
| Share-alike required? | No |
How to credit this work
Gilda Carrasco; Pabla Rebolledo; Fernando Fuentes-Peñailillo; Rolón Gómez; Paula Manríquez (2025). Substrate Effects on Yield and Nutritional Quality of Amaranth Microgreens in Floating-Tray Hydroponics. Horticulturae. https://doi.org/10.3390/horticulturae11111395 Licensed under Creative Commons Attribution 4.0 (https://creativecommons.org/licenses/by/4.0/). Hosted by EVEC Athens (microgreens.org.gr). No changes were made to this article. Provided as-is, without warranties. EVEC Athens is not affiliated with, and this copy is not endorsed by, the authors or the publisher.
Explore this on our site
- How to grow it: Amaranth microgreens — growing guide
- Related reading: Nutritional and sustainability potential of cereal microgreens
- Related reading: Protein rich microgreens pea lentil chickpea and sunflower
- Related reading: Microgreens the future of urban agriculture and superfoods part i
About this copy
This is a copy of the published article, hosted by EVEC Athens for free educational use under its open licence. The permanent scientific reference is the DOI above. We have not altered the file in any way. If you are an author or rights holder and want this copy removed, please use our notice and takedown procedure. We acknowledge every request within five working days, and act within ten.
Co-funded by the European Union.
This portal presents the microgreens methodology; the organisation behind it is EVEC Athens — the European Voluntary and Educational Center (evec.org.gr). Views and opinions expressed are those of the author(s) only and do not necessarily reflect those of the European Union or the European Commission. Neither the European Union nor the granting authority can be held responsible for them.
Open licence. Except where stated otherwise, the educational materials on this portal are licensed under CC BY 4.0 — free to use, adapt and share, including commercially, with credit. See the licence terms.
Accessibility. We aim for WCAG 2.1 AA and publish what does and does not yet meet it — see the accessibility statement. If anything here blocks you, tell us and we will send the material in a format that works for you.