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Uniformity of environmental conditions and plant growth in a hydroponic culture system for use in a growth room with aerial CO2 controlA 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.
Document ID
Document Type
Reprint (Version printed in journal)
Vessey, J. K. (North Carolina State University Raleigh 27695-7619)
York, E. K.
Henry, L. T.
Raper, C. D. Jr
Raper CD, J. r.
Date Acquired
August 22, 2013
Publication Date
January 1, 1988
Publication Information
Publication: Biotronics
Volume: 17
ISSN: 0289-0011
Subject Category
Life Sciences (General)
Funding Number(s)
Distribution Limits
NASA Discipline Life Support Systems
Non-NASA Center
NASA Discipline Number 61-10