Beijing Research Center of Intelligent Equipment for Agriculture, Beijing Academy of Agriculture and Forestry Sciences, Beijing, 100097, China.
Key Laboratory of Urban Agriculture (North China), Ministry of Agriculture and Rural Affairs, Beijing, China.
Sci Rep. 2021 Apr 16;11(1):8374. doi: 10.1038/s41598-021-87911-7.
Since red (R) and blue (B) LED light has different quantum efficiency and photoelectric conversion efficiency, mixed RB with different proportions of R and B results in varied energy consumption. In order to improve the energy use efficiency of the closed-type plant production systems, the effects of R and B proportions on the electric use efficiency (EUE), light use efficiency (LUE) as well as the quality of butter leaf lettuce were evaluated in this study. Lettuce seedlings were cultivated in a plant factory with artificial lighting (PFAL) and subjected to eleven combinations of R and B (100%R, 90%R, 80%R, 70%R, 60%R, 50%R, 40%R, 30%R, 20%R, 10%R, 0%R; the rest of the photons in each treatment were B) with the same total photosynthetic photon flux density (PPFD) and photoperiod (200 ± 3 μmol·m·s, 16 h) for 35 days. The results showed that palpable petiole distortion appeared when R proportion was more than 70% and the distortion was aggravated with the increase of R proportion. The highest EUE and LUE were both detected in lettuce under 90%R treatment, which were respectively 3.64% and 1.20%. The least number of photons and the least electricity amount required to produce 1 g dry weight of lettuce was respectively 2.92 mol and 1.67 MJ, which were both detected in lettuce treated with 90%R. The sucrose content in lettuce treated with more than 50%R was significantly higher than those treated with less than 50%R (50%R included). Lettuce treated with 80%R possessed the highest soluble sugar content as well as the lowest crude fiber and nitrate content (not significantly different with the minimum values). R proportion exceeding 50% in mixed RB light was beneficial to the accumulation of hexose and sucrose, as well as the decomposition of nitrate in lettuce. The vitamin C content in lettuce treated with 100%R was significantly higher than that in lettuce under other treatments in the study. On the whole, the study indicated that the proportions of R and B affected the energy use efficiency and quality of lettuce in closed plant factory, however the responses of plants to the proportions of R and B varied according to different indexes. Thus, some indexes of top priority should be determined before choosing the optimal proportions of R and B.
由于红色（R）和蓝色（B）LED 光的量子效率和光电转换效率不同，因此混合不同比例的 R 和 B 会导致能量消耗的变化。为了提高封闭式植物生产系统的能源利用效率，本研究评估了 R 和 B 比例对电利用效率（EUE）、光利用效率（LUE）以及生菜品质的影响。生菜幼苗在人工光照植物工厂（PFAL）中进行培育，并接受了 11 种 R 和 B 的组合（100%R、90%R、80%R、70%R、60%R、50%R、40%R、30%R、20%R、10%R、0%R；每种处理的其余光子均为 B），总光合光子通量密度（PPFD）和光照时间（200±3μmol·m·s，16 h）相同，持续 35 天。结果表明，当 R 比例超过 70%时，可明显观察到叶柄变形，并且随着 R 比例的增加，变形加剧。在 90%R 处理下，生菜的 EUE 和 LUE 最高，分别为 3.64%和 1.20%。生产 1 g 生菜干重所需的最少光子数和电量分别为 2.92 mol 和 1.67 MJ，均在 90%R 处理下的生菜中检测到。在 50%R 以上处理的生菜中，蔗糖含量明显高于 50%R 以下处理的生菜（包括 50%R）。在 80%R 处理下，生菜的可溶性糖含量最高，粗纤维和硝酸盐含量最低（与最小值无显著差异）。混合 RB 光中 R 比例超过 50%有利于生菜中己糖和蔗糖的积累，以及硝酸盐的分解。在 100%R 处理下的生菜中，维生素 C 含量明显高于其他处理下的生菜。总的来说，本研究表明，R 和 B 的比例影响封闭式植物工厂中生菜的能量利用效率和品质，但植物对 R 和 B 比例的响应因不同指标而异。因此，在选择最佳 R 和 B 比例之前，应确定一些优先指标。
