Vessey J K, York E K, Henry L T, Raper C D
Department of Soil Science, North Carolina State University, Raleigh 27695-7619.
Biotronics. 1988;17:79-94.
A portable system of hydroponic culture was developed that maintained temperature, pH, and nutrient concentrations of circulating nutrient solutions. The hydroponic system is used within a controlled-environment room (CER) for control of aerial environment. The CER was equipped with an auto-calibrating system for atmospheric CO2 control. The control systems for the hydroponic chambers were able to maintain acidity within +/- 0.2 pH units and the temperature with +/- 0.5 degree C. Mixing time for the 200-liter volume of solution within a hydroponic chamber was less than 12 min. The CO2 control system was able to maintain aerial concentrations within +/- 10 ppm CO2 during the light period. The only gradient found to occur within the hydroponic chambers or CER was a slight gradient in aerial temperature along the length of hydroponic chambers. Growth of soybeans [Glycine max (L.) Merr.] was characterized during a 3-week period of vegetative development by leaf number and area, plant dry weight, total N content of plants, and N depletion from the nutrient solution. The growth characteristics among populations for three hydroponic chambers within the CER were not significantly different, and the percent standard errors of means of the measurements within populations from each chamber were nearly all less than 10%. Thus, the uniformity of plant growth reflected the uniformity of environmental conditions.
开发了一种便携式水培系统，该系统可维持循环营养液的温度、pH值和养分浓度。水培系统在可控环境室（CER）内使用，用于控制空气环境。CER配备了用于控制大气CO2的自动校准系统。水培室的控制系统能够将酸度维持在±0.2个pH单位以内，温度维持在±0.5摄氏度以内。水培室内200升溶液的混合时间少于12分钟。CO2控制系统能够在光照期间将空气浓度维持在±10 ppm CO2以内。在水培室或CER内发现的唯一梯度是沿水培室长度方向的空气温度略有梯度。在为期3周的营养生长发育期间，通过叶片数量和面积、植株干重、植株总氮含量以及营养液中的氮消耗来表征大豆[Glycine max (L.) Merr.]的生长情况。CER内三个水培室中不同种群间的生长特征没有显著差异，每个室内种群测量值的平均标准误差百分比几乎都小于10%。因此，植物生长的均匀性反映了环境条件 的均匀性。
