The Suitability of Algae Solution in Pea Microgreens Cultivation under Different Light Intensities

Microgreens are young plants grown from vegetables, grain, or herb seeds in a controlled environment with artificial lighting. LED modules are the preferred option for indoor and vertical farming. Light intensity (LI) is crucial for plant growth and the synthesis of phytochemicals. The study aimed to assess whether growing microgreens under low light intensity but with the addition of algae would produce plants with similar parameters (biometric, active compound content) to those grown under higher light intensity. The experiment evaluated LED white light at two intensity levels: 115 µmol m −2 s −1 (low light, LL) and 230 µmol m −2 s −1 (high light, HL). Pea seeds were soaked in a 10% solution of Chlorella vulgaris algae or water before sowing, and the plants were watered or sprayed during growth with the same solutions. The results showed no positive effect of algae on plant biometric traits. However, plants treated with algae had a significantly higher chlorophyll and carotenoid content index. Light significantly influenced pea growth, with plants grown under high light (HL) showing greater weight, height, and plant area. Additionally, changes in the photosynthetic apparatus and light stress were observed in microgreens watered with water (AW and WW) under high light during the vegetative phase. Raman spectra also indicated changes in the chemical composition of microgreens’ leaves based on light intensity and treatment. Microgreens treated with algae solution during seed soaking and water during the vegetative phase produced much more carotenoids compared to other variants.