• 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.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.48 no.3
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• pp.205-208
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• 2003

This study was conducted to develop a technology for raising rice hydroponically seedlings using the bed in which the seedlings grew in nutrient solution without soil. In Hydroponic rice seedlings, two nutrient solutions (Yashida and Wonsi) were evaluated with four supplying methods $[$3 times (2 days, 8 days and 12 days after seeding), 2 times (5 days and 10 days after seeding), and 1 time (5 days and 10 days after seeding)$]$1, Seedling growth was not different between the two solutions. However, tensile strength of root-mat was higher in Yoshida solution than in Wonsi solution. The more frequent supply of solution resulted in the better seedling growth but in the weaker root mat. Utilization efficiency of the solution minerals was not different in N content regardless of supplying frequencies, but higher in r, K, Ca and Mg when supplied only once on the 5 days after seeding.

• Journal of agriculture & life science
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• v.53 no.4
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• pp.19-28
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• 2019

This study was conducted to investigate the effect of nutrient solution strength and duration of nutrient starvation on the growth and development of strawberry (Fragaria x ananassa Duch.) 'Maehyang' and 'Sulhyang' at the flowering stage. Cuttings of runner plants were stuck on November 23th, 2017 and were covered with a layer of black plastic film to block light from penetrating and keep the relative humidity high. The black plastic film was removed after 16 days and rooted plants were cultivated for one month with irrigation of water. The Yamazaki nutrient solution with an electrical conductivity (EC) of 1.85 or 3.71 dS·m-1 (1x or 2x ionic strength, respectively) and pH 5.55 was fed to plants after either 0 (control), 1, 3 or 5 weeks of nutrient starvation to the end of experiment. Plant height in both cultivars decreased gradually with the increase in duration of nutritional starvation. The earlier the nutritional starvation started, the smaller the shoot fresh weight of 'Maehyang'. Hence the greatest shoot fresh weight was obtained in the control which was supplied with the nutrient solution continuously. Shoot fresh weight of 'Sulhyang' was the greatest in 1x ionic strength and one week of nutrient starvation before planting. Although number of flowers on the first flower cluster of 'Maehyang' and 'Sulhyang' showed no significant differences, 'Maehyang' had the greatest number of flowers in the 2x ionic strength solution and one week of nutrient starvation before planting, while 'Sulhyang' had that in the 1x ionic strength treatment. These results suggest that it is considered effective to supply a nutrient solution at a low concentration for a short period of time for increasing the number of flower differentiated on the first flower cluster in both cultivars.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 2003.04a
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• pp.30-33
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• 2003

최근 건강에 대한 인지도가 높아감에 따라 농산물의 안정성 요구도가 증가되고 있으며 환경농업의 필요성이 크게 대두되고 있고, 서구식 식문화의 급속한 도입으로 패스트푸드 식품과 육류 소비량의 증가로 신선채소의 소비가 증가되고 있는데 이에 따른 생산비 절감과 안정생산 기술이 요구되고 있다. 따라서 양액 공급에 따른 전력 등 에너지가 필요치 않고 일종의 폐쇄식 수경재배 방법으로써 작물이 주위 환경에 따라 양수분 흡수량이 다르므로 모세관 현상으로 배지내의 수분이 작물의 흡수한 만큼 공급되어 이용되고 배액이 없으므로 공해의 염려가 없고 고품질 채소의 저비용 생산이 가능한 새로운 모관양액공급시스템을 이용하여 양액공급시스템의 효율성을 검정하고 네트멜론과 몇 가지 엽채소의 생육특성을 구명코자 수행하였다. (중략)

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 1998.05a
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• pp.83-88
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• 1998

양액재배는 세계적으로 각광을 받으며 그 면적이 급속히 증가하고 있고 이에 따라 우리나라의 양액재배 면적도 '94년 63㏊에서 '97년 413.9㏊로 급속히 증가하였다. 양액재배의 특징은 양분의 농도를 쉽게 변경하여 공급할 수 있는 장점이 있으나 토양이 갖는 완충능이 감소되는 조건하에서의 재배이므로 항상 작물의 생육에 합치되는 배양액의 관리가 필요하다. (중략)

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 1998.05a
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• pp.128-130
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• 1998

지난날 각 가정에 많이 사용해왔던 등잔불이 심지라는 섬유제품을 통하여 기름이 올라오는 원리 즉 모세관 현상을 이용한 조명 방법이었다. 고형배지를 이용한 양액재배에서 양액의 공급은 동력기기를 이용한 소위 에너지를 많이 소비하는 방법이 거의 전부라 할 수 있다. 에너지를 절약할수 있는 방법을 생각하던 중에 섬유직조물들이 갖고 있는 모세관현상을 이용한 급액방법을 몇가지 섬유제품을 가지고 시도해 보았는데 예상했던 것 보다 훨씬 다양하고 좋은 결과를 얻었다. (중략)

• Journal of Bio-Environment Control
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• v.9 no.1
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• pp.11-19
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• 2000

In recent, multi-sector nutriculture in which each sectors are managed with different compositions and supplying amounts of nutrient solution is being prevalent especially in large-scale greenhouses. This study was carried out to develop an automatic mixing and supplying system of nutrient solution for the multi-sector greenhouse which can control various compositions of nutrient solution and supplying amounts for each sector. The stock solution control device could control discharge of the stock solution with device actuating time. The experimental result showed high correlation between the discharge and the actuating time. The system could make nutrient solution of various compositions and showed possibility of changing compositions of nutrient solution according to changes of growth stages or environments. Undesirable remnant nutrient-solution effect on the next supply was decreased by lowering RC of the previous nutrient solution remaining in the tank and supply pipe through rinse process. To evaluate performance of the developed system, experiments that compare N $O_3$$^{[-10]}$ , and P $O_4$$^{3-}$ concentrations of nutrient solution made in laboratory level with those made by the developed system were conducted. The experimental results showed that the deviations for N $O_3$$^{[-10]}$ , and P $O_4$$^{3-}$ concentrations of nutrient solution composited by the developed system were -2.36％ and -5.15％, respectively.

• 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.

• 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.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2003.07a
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• pp.390-395
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• 2003

우리나라의 수경재배 면적은 2001년말 현재 736㏊로 순환식이 296㏊, 비순환식이 440㏊를 차지하고 있다. 수경재배에서의 양액관리방법은 작물 및 재배시스템의 종류에 따라 다르지만 작물이 흡수하고 남은 양액이 양액탱크와 재배조사이를 왕복순환되는 순환방식과 양액탱크에서 재배조로 공급된 후 배출폐기되는 비순환방식(흘러버림식)으로 나누어진다. (중략)