• Journal of Bio-Environment Control
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• v.20 no.1
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• pp.33-39
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• 2011

This experiment was carried out to understand the characteristics of inorganic ion uptake of strawberries to establish a labor saving, environmentally sound closed hydroponic system. Nitrate nitrogen is absorbed in the perlite and granule rockwood with the almost same rate and in the cocopeat with a little bit higher concentration. At the early growth stage, phosphate was absorbed in comparatively high rate, but it is gradually declining to $4me{\cdot}L^{-1}$ in the three treatments except for reused medium. Four treatments showed different absorption rates for potassium, respectively, however, it became $3{\sim}5me{\cdot}L^{-1}$ gradually. But there was few sign to absorb potassium in the reused medium. High concentration of calcium was absorbed in the cocopeat medium and the lowest absorption rate in the granule rockwool, and it turned out to be $2{\sim}3me{\cdot}L^{-1}$ absorption concentration rate in the perlite. All three treatments showed $1me{\cdot}L^{-1}$ at the average absorption concentration rate of magnesium. Iron showed high absorption rate but it showed steadily 1~2 ppm absorption rate. Results of this experiment will be utilized for developing the new substrates for strawberry closed hydroponic system.