ABSTRACT Light intensity and nitrogen concentration in nutrient solutions are two main factors affecting the growth and nutritional quality of lettuce(Lactuca sativa L.). This study investigated the method of regulating vegetable cultivation through the interactive control of the light environment and solution ratio. A quadratic regression orthogonal model was developed to understand the role of light intensity (43 to 237 µmol m−2s−1) and nitrogen concentration (4.3 to 23.7 mmol L−1) in lettuce growth. Dry weight, vitamin C, and nitrate contents were measured and modelled to understand the coupling effect of light intensity and nitrogen concentration on lettuce. The optimised conditions for lettuce growth were 237 µmol m−2 s−1 of light intensity and 9.2 mmol L−1 of nitrogen concentration, and these conditions were predicted to produce lettuce with an average dry biomass of 3.9 g plant−1, 149.9 µg g−1 of Vitamin C, and 212.1 µg g−1 of nitrate content based on their respective weighting factors (0.50, 0.25, and 0.25). The lettuce yield and quality were verified using the modelled optimised growth conditions and the lettuce grown was indeed more nutritional compared to the commercially available lettuce. The findings are important for mass production of lettuce in plant factories and greenhouses.

中文翻译：

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调节生菜产量、维生素C和硝酸盐含量的溶液中光强度和氮浓度的优化

摘要 营养液中光照强度和氮浓度是影响莴苣（Lactuca sativa L.）生长和营养品质的两个主要因素。本研究探讨了通过光环境和溶液比例的交互控制来调节蔬菜栽培的方法。开发了二次回归正交模型以了解光强度（43 至 237 µmol m-2s-1）和氮浓度（4.3 至 23.7 mmol L-1）在生菜生长中的作用。对干重、维生素 C 和硝酸盐含量进行了测量和建模，以了解光照强度和氮浓度对生菜的耦合影响。生菜生长的优化条件是237 µmol m-2 s-1 的光强度和9.2 mmol L-1 的氮浓度，根据它们各自的加权因子（0.50、0.25 和 0.25），预测这些条件生产的生菜的平均干生物量为 3.9 g 植物−1、149.9 µg g−1 维生素 C 和 212.1 µg g−1 硝酸盐含量。 0.25）。使用模型优化的生长条件验证生菜产量和质量，与市售生菜相比，种植的生菜确实更有营养。这些发现对于在植物工厂和温室中大规模生产生菜很重要。使用模型优化的生长条件验证生菜产量和质量，与市售生菜相比，种植的生菜确实更有营养。这些发现对于在植物工厂和温室中大规模生产生菜很重要。使用模型优化的生长条件验证生菜产量和质量，与市售生菜相比，种植的生菜确实更有营养。这些发现对于在植物工厂和温室中大规模生产生菜很重要。