Wheeler R M, Mackowiak C L, Sager J C, Yorio N C, Knott W M, Berry W L
National Aeronautics and Space Administration Biomedical Operations and Research Office, Kennedy Space Center, FL 32899, USA.
J Am Soc Hortic Sci. 1994 May;119(3):610-5.
Two studies were conducted in which 'Waldmann's Green' lettuce (Lactuca sativa L.) was grown hydroponically from seed to harvest in a large (20-m2), atmospherically closed growth chamber for the National Aeronautics and Space Administration's controlled ecological life support system (CELSS) program. The first study used metal-halide (MH) lamps [280 micromoles m-2 s-1 photosynthetic photon flux (PPF)], whereas the second used high-pressure sodium (HPS) lamps (293 micromoles m-2 s-1). Both studies used a 16-hour photoperiod, a constant air temperature (22 to 23C), and 1000 micromoles mol-1 CO2 during the light period. In each study, canopy photosynthesis and evapotranspiration (ET) rates were highly correlated to canopy cover, with absolute rates peaking at harvest (28 days after planting ) at 17 micromoles CO2/m2 per sec and 4 liters m-2 day-1, respectively. When normalized for actual canopy cover, photosynthesis and ET rates per unit canopy area decreased with age (between 15 and 28 days after planting). Canopy cover increased earlier during the study with HPS lamps, and final shoot yields averaged 183 g fresh mass (FM)/plant 8.8 g dry mass (DM)/plant. Shoot yields in the first study with MH lamps averaged 129 g FM/plant and 6.8 g DM/plant. Analysis of leaf tissue showed that ash levels from both studies averaged 22% and K levels ranged from 15% to 17% of tissue DM. Results suggest that lettuce should be easily adaptable to a CELSS with moderate lighting and that plant spacing or transplant schemes are needed to maximize canopy light interception and sustained efficient CO2 removal and water production.
开展了两项研究，在一个大型（20平方米）、大气封闭的生长室内，将“瓦尔德曼绿”生菜（Lactuca sativa L.）从种子种植到收获进行水培，用于美国国家航空航天局的受控生态生命支持系统（CELSS）项目。第一项研究使用金属卤化物（MH）灯[光合光子通量（PPF）为280微摩尔·米⁻²·秒⁻¹]，而第二项研究使用高压钠（HPS）灯（293微摩尔·米⁻²·秒⁻¹）。两项研究均采用16小时光周期、恒定气温（22至23摄氏度），并在光照期采用1000微摩尔·摩尔⁻¹二氧化碳。在每项研究中，冠层光合作用和蒸散（ET）速率与冠层覆盖高度相关，绝对速率在收获期（种植后28天）达到峰值，分别为17微摩尔二氧化碳/平方米·秒和4升·米⁻²·天⁻¹。按实际冠层覆盖进行归一化后，单位冠层面积的光合作用和ET速率随植株年龄增长而下降（种植后15至28天）。在使用HPS灯的研究中，冠层覆盖在研究前期增加得更早，最终地上部产量平均为183克鲜重（FM）/株和8.8克干重（DM）/株。第一项使用MH灯的研究中地上部产量平均为129克FM/株和6.8克DM/株。叶片组织分析表明，两项研究的灰分含量平均为22%，钾含量占组织干重的15%至17%。结果表明，生菜应易于适应光照适中的CELSS，并且需要种植间距或移栽方案来最大化冠层对光的截留以及持续高效地去除二氧化碳和生产水。
