1College of Horticulture，Hebei Agricultural University，Baoding 071000，Hebei，China；2Academy of Agricultural Planning and Engineering，Ministry of Agriculture and Rural Aff airs，Beijing 100125，China；3Key Laboratory of North China Water-Saving Irrigation Engineering，Baoding 071000，Hebei，China
摘要 以半结球叶用莴苣品种富兰德里为试材，在深液流水培（DFT）模式下研究了营养液浓度动态调控和液位高度对叶用莴苣生长及品质的影响。结果表明：随着营养液浓度调控幅度的提高，叶用莴苣生长指标和可溶性蛋白、可溶性糖、VC等品质指标均呈先上升后下降的变化趋势，以每8 d提高0.36 mS·cm-1 处理的效果最好，叶片长、叶片宽、叶绿素a含量、总叶绿素含量、根系活力、地上部和地下部鲜质量及干质量、可溶性蛋白含量、可溶性糖含量、VC含量均显著高于其他处理，其中地上部鲜质量较其他处理提高了22.3%～57.9%；不同营养液液位高度对叶用莴苣生长和品质的影响存在显著差异，12～16 cm 液位高度处理的植株生长和品质总体上优于其他处理，4 cm 液位高度处理的效果较差。
Abstract：The eff ects of dynamic regulation of nutrient solution concentration and depth on the growth and quality of lettuce were studied under deep flow technique（DFT）mode with semi-heading lettuce variety‘Flanders’as the test material．The results showed that with the increase of nutrient solution concentration，both growth indicators and quality indicators such as soluble protein，soluble sugar，and VC initially improved before declining．The best results were achieved with a nutrient concentration increment of 0.36 mS·cm?1 every eight days，which significantly enhanced leaf length，leaf width，chlorophyll-a content，total chlorophyll content，root vitality，both the fresh and dry weight of aboveground and underground parts，soluble protein content，soluble sugar content，and VC content compared to other treatments．The fresh weight of aboveground parts increasing by 22.3% to 57.9%．Additionally，the study identified significant variations in plant growth and quality based on the depth of the nutrient solution．The plants grown at liquid levels of 12-16 cm exhibited superior growth and quality outcomes，while those grown at a 4 cm liquid level showed poorer performance．
