Ohler T A, Mitchell C A
NASA Specialized Center of Research and Training in Bioregenerative Life Support, Department of Horticulture, Purdue University, West Lafayette, IN 47907-1165, USA.
Life Support Biosph Sci. 1995 Summer;2(1):3-9.
Plant density and atmospheric carbon dioxide level were manipulated to optimize productivity of cowpea [Vigna unguiculata (L.) Walp] for future use in a space-deployed Controlled Ecological Life Support System. Cowpea breeding line IT87D-941-1 was grown at plant densities of 3.6, 7.2, 10.7, or 14.3 plants m-2 in a growth chamber maintained at 400 (control) or 1200 (elevated) micromoles CO2 mol-1. Both green leaves and dried seeds were harvested as edible yield. Crop productivity was measured by edible yield rate (EYR), harvest index (HI), yield efficiency rate (YER), energy efficiency, and net photosynthesis (Pn). Increasing plant density within a canopy tended to increase EYR, but decreased HI and YER. Elevated CO2 also increased EYR, but decreased HI and YER as well. However, when the energy penalty for crop production was taken into consideration, cowpea crops grown under elevated CO2 were more productive than those grown at control CO2. Pn averaged 15 micromoles CO2 m-2 s-1 for cowpeas grown at 400 micromoles CO2 mol-1. Low Pn at the beginning and end of the cropping cycle indicated waste of high irradiance lighting during those times.
对豇豆[Vigna unguiculata (L.) Walp]的种植密度和大气二氧化碳水平进行了调控，以优化其生产力，供未来在太空部署的受控生态生命支持系统中使用。豇豆育种系IT87D - 941 - 1在生长室中种植，种植密度分别为3.6、7.2、10.7或14.3株/m²，生长室的二氧化碳浓度维持在400（对照）或1200（升高）微摩尔CO₂/摩尔。收获绿叶和干种子作为可食用产量。通过可食用产量率（EYR）、收获指数（HI）、产量效率率（YER）、能量效率和净光合作用（Pn）来衡量作物生产力。在冠层内增加种植密度往往会提高EYR，但会降低HI和YER。二氧化碳浓度升高也会提高EYR，但同样会降低HI和YER。然而，当考虑到作物生产的能量消耗时，在二氧化碳浓度升高条件下种植的豇豆作物比在对照二氧化碳浓度下种植的作物生产力更高。对于在400微摩尔CO₂/摩尔条件下种植的豇豆，Pn平均为15微摩尔CO₂/m²·秒。种植周期开始和结束时的低Pn表明在这些时间段高辐照照明被浪费了。
