• Journal of Bio-Environment Control
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• v.4 no.1
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• pp.43-49
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• 1995

The main purpose of these studies were to clarify differences in Cheju - scoria and other solid media on quantity and quality of cherry tomatoes and on shift of component of the nutrient solution, and to use Practically Cheju-scoria as an excellent solid culture medium. The results obtained were summarized as follows ; 1. Among scoria plots, the rates of dry weights, fruits and their sugar-acid ratio were higher in the plot that was drained well with deep flow for one hour once a day. 2. Fresh fruit weights were lighter in rockwool and deep flow technique, but larger in scoria, Hyugashi (artificial gravel, $\Phi$10-12mm) and perlite in moving to higher flower cluster. 3. The results of analysis on microelement among solution components showed decrease of concentrations of P and K in the period of growth and development. 4. Yields and brix of cherry tomato showed a tendency to increase in rockwool and Hyugashi than anothers. 5. The concentration of fertilizer base was increased in general solution culture. Transpiration and absorption were similar in scoria plot and other media. 6. More studies of the Cheju-scoria development is required in order to use it as a solid medium for solution culture.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.5
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• pp.1059-1065
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• 2005

In this study, an nutrient solution control system have been designed and implemented, which controls the density of nutrient and the nutrient supply automatically using embedded real time operating system and fuzzy control algorithm. The factors which affect the growth of crop consist of solar radiation, external temperature, and external humidity. Also, nutrient temperature, electric conductivity(ED, and pH are monitored. According to the surveyed results, a fuzzy control algorithm for nutrient control is developed in order to control the density of nutrient and the nutrient supply. The exclusive embedded controller which consists of an embedded real time operating system, a korean LCD, and a graphic is developed for common users.

• Horticultural Science & Technology
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• v.16 no.1
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• pp.37-39
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• 1998

This study was carried out to investigate the effects of nutrient solution concentration, irrigation frequency on growth, flowering, and cut flower longevity of Dendranthema grandiflorum (Ramat.) Kitamura 'Shuhouno-chikara' hydroponically grown in perlite media. Not only stem length but also mineral contents of each plant organ in nutrient solution culture were much higher than those in soil culture. 1/2S of nutrient solution was good at early stage, but 1S of nutrient solution was better as chrysanthemum growth progressed. Among different concentrations of nutrient solution, mineral contents of each plant part showed no significant difference. 1S treatment of nutrient solution increased the vase life by 3 days than 2S treatment. The growth and mineral contents of each plant organ were great in plants irrigated 8 times a day, because of high moisture contents of medium and high water availability, followed by more frequent nutrient replenishment near roots. There was no correlation between nutrient solution concentration and vase life of cut flower grown in nutrient solution culture. Cut flowers irrigated twice per day had the longer vase life than other treatments (4, 8 times).

• Horticultural Science & Technology
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• v.19 no.3
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• pp.338-341
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• 2001

A new passive nutrient supplying system (PNS) was designed. The experiment was conducted to compare PNS with automatic hydroponic system (AHS) by investigating the growth characteristics of muskmelon (Cucumis melo L.) in spring and summer. No significant differences in growth characteristics of leaf area and shoot dry weight were observed between PNS and AHS. However, better netting of melon fruit was shown in PNS. Sugar content of melon fruit was also $1.0-2.0Brix^{\circ}$ higher in PNS than in AHS. The suitable substrate for melon culture with PNS was the mixture of perlite 70% and rice hull 30%. These results suggested that new PNS could be introduced to growers without any loss of fruit yield and quality of muskmelon.

• Journal of Bio-Environment Control
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• v.24 no.4
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• pp.271-274
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• 2015

The objective of this study was to investigate the effects of composition of nutrient solution on the growth and quality of baby leaf vegetables (tat soi, romaine lettuce, beet, and red radish) hydroponically cultivated in plant factory. The seeds of four vegetable crops were sown in urethane sponges and cultivated for 14 days in a plant factory. Light intensity and photoperiod were $110{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ and 16 h, respectively; and air temperature in photo/darkperiod was maintained at $25/20^{\circ}C$. Tap water was used for irrigation for 7 days after sowing, and then plants were irrigated for 7 days using tap water and the nutrient solutions of Korea Wonshi, Japan Enshi, and Yamazaki for lettuce. At 14 days after sowing, the fresh weight of tah soi was highest in the nutrient solution of Yamazaki for lettuce, and there were no significant differences among nutrient solutions in beet and red radish. When we compared leaf color using Hunter's a value, the nutrient solution of Korea Wonshi and Japan Enshi increased green color in baby leaf vegetables, while the nutrient solution of Yamazaki for lettuce increased red color. Total phenolic content of romaine lettuce was highest in the nutrient solution of Korea Wonshi, but tat soi, beet, and red radish showed no significant differences among nutrient solutions in total phenolic contents. From these results, we suggest that using the nutrient solution of Korea Wonshi can enhance the growth and quality of romaine lettuce and the nutrient solution of Yamazaki for lettuce is appropriate for enhancing the growth and red color of beet and red radish in plant factory.

• Korean Journal of Organic Agriculture
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• v.17 no.3
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• pp.357-370
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• 2009

This experiment was conducted to investigate the effects of compost leachate and concentrated slurry on growth of tomato in hydroponic culture. In process of composting, compost leachate was produced water was through a saturated compost heap. The concentrated slurry was produced by filtration and concentration by membrane process. Filtration of pig slurry was necessary to prevent the hose clogging in hydroponics culture. The treatments of this experiment were consisted of seven different liquid fertilizers; compost leachate(CL), concentrated pig slurry (CS), compost leachate+byproduct(CL+BP), concentrated pig slurry+byproduct(CS+BP), compost leachate 50%+nutrient solution50%(CL+NS), concentrated pig slurry 50%+nutrient solution50%(CS+NS) and nutrient solution(NS) for tomato based on nitrogen content. The chemical nutrient solution was the solution of National Horticulture Research Station for the growth of tomato. The concentration of nutrient solution was adjusted a range of $1.6{\sim}2.0 mS/cm$ in EC. 1. The compost leachate and concentrated pig slurry were low in phosphorus(P), calcium(Ca), magnesium(Mg), but rich in potassium(K). 2. Plant height, SPAD value of tomato was highest in the plot of CS+NS, intermediate in CL, CS+BP, and lowest in 100% concentrated pig slurry. 3. The tomato yield of compost leachate plot was 91% compared with inorganic nutrient solution. The compost leachate solution could be used as a nutrition solution of tomato in organic hydroponics. 4. The growth including plant height, SPAD value, fruit number, fruit weight and yield of tomato in the CL 50%+NS 50% was similar in the control. In conclusion, the mixture solution of 50% pig slurry and 50% nutrient solution could be used as a nutrition solution of tomato hydroponic culture.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 1995.04a
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• pp.64-65
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• 1995

양액재배는 토양재배보다 시설비가 많이 든다는 것을 제외하고는 여러 가지 면에서 유리하다. 우리나라의 양액재배 면적은 1994에 59.5ha로서 앞으로 그 면적은 급속도로 늘어날 전망이다. 양액재배가 성립되려면 몇 가지 요건들이 갖추어져야 하는데 그 중 용수의 수질상태는 매우 중요하다. 용수로써 사용되는 물은 주로 지하수, 하천수, 수도물, 빗물 등인데 우리나라는 대부분 지하수를 이용하고 있다. 용수중 무기성분의 농도는 순수한 물이 이상적이지만 가능한 한 그 농도가 낮은 것이 좋다. (중략)

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 1994.05a
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• pp.115-116
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• 1994

최근 양액재배 면적의 급격한 증가는 경기도 일원의 서울 근교에 한정되었던 양액재배 시설을 전국적으로 확산시키는 계기가 되었다. 따라서 일부 지역에서는 지하수에 함유되어 있는 특정성분의 농도가 지나치게 높아서 작물 재배가 어려운 경우도 있다. 물론 재배 전에 철저한 수질검사를 거쳐야 하겠으나 그렇지 못한 경우도 많은 실정이다. 수도물에 함유되어 있는 Cl의 농도는 30ppm정도라고 하며, 양액재배에 적합한 용수의 Na고 Cl의 농도도 30ppm 정도라고 한다. (중략)

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 1995.10a
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• pp.54-57
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• 1995

최근 양액재배 농가의 급증과 함께 토마토 양액재배가 증가하고 있다. 그러나, 토마토에 대한 재배방법은 많이 연구되어왔지만, 우리 나라에서는 아직까지 여름철 고온에도 착과가 어느정도 이루어지는 양액재배에 적합한 품종선택이 되어있지 않기 때문에 본 실험에서는 국내품종과 국외품종을 이용하여 여름철 고온기를 잘 넘길 수 있으며, 양액재배에 적합한 품종을 선발하고자 실시하였다. (중략)

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 2002.11a
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• pp.285-288
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• 2002

우리 나라의 양액재배 면적은 2001년말 현재 736ha로 순환식이 296ha, 비순환식이 440ha를 차지하고 있다. 순환식은 작물이 흡수하고 남은 양액을 다시 사용하는 방식으로 NFT또는 DFT에서 많이 볼 수 있으며, 비순환식은 재배조에서 배출되어 나온 양액을 재사용하지 않고 시설 밖으로 흘러버리는 방식으로서 암면재배나 펄라이트재배에서 많이 채택되는 방식이다. (중략)