• Journal of the Korea Academia-Industrial cooperation Society
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• v.7 no.2
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• pp.188-194
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• 2006

Since the late 1920's possibility of commercial hydroponics was testified practically. Hydroponics is used as environmentally friendly agriculture production system recently with high effectiveness. Now that existing irrigation control systems such as time control or solar radiation control cannot satisfy stable water content in root substrates, the needs for new irrigation system keep increasing. In this paper, we proposed environmentally friendly automatic irrigation management system by employing automation system based on electronic control system, which could solve problems based on manual irrigation management system. In addition, it suggested to be applied to any crops and will be able to overcome existing limit in irrigation by measuring the water content of root substrate in realtime.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.5 no.1
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• pp.7-12
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• 2004

The steps related to the nutrient solution management were divided into 4 categories. The resistance for water movement in every steps was proposed. The priorities among the steps were set according to the cultural situation, which were used as the basis for the management in perlite bag culture. The enhancement of historical root development is especially critical, as well as how to supply essential water efficiently by minimizing the water movement distance to the root, which is the narrowest neck of a bottle in solution management.

• Proceedings of the KAIS Fall Conference
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• 2007.11a
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• pp.181-184
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• 2007

본 논문에서는 수경재배의 비중이 늘어난 만큼 새로운 친환경 저자 정밀 급액관리의 개발이 시급함을 언급하고 현재의 한계를 극복 할 수 있는 배액 제어법을 개발 하고자 한다. 급액관리 임베디드 시스템은 정확한 시간 제어, 일사량 제어 전자 방식으로서 수동식 배액 제어법의 문제점을 해결할 수 있으며 뿐만 아니라 사용자가 온실의 없을 경우에도 급액관리를 할 수 있도록 web기반으로 구현하여 편의를 도모하였다.

• Journal of agriculture & life science
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• v.44 no.5
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• pp.129-135
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• 2010

This experiment was carried out to commercialize an irrigation control system by finding out problems and solving them in application of a nutrient supply system through this experiment. Its efficiency had been tested through hydroponic cultivation of tomato and cucumber using this system in the farmer's plastic house (1-2W, 20a : Yanggyo-ri, Oseong-myeon Gyeonggi-do) from November. 2006, too. In the first cultivation, tomato seeds (cultivar Coco, Takii Seed Co. Japan) were sowed on November 8, 2006, and transplanted on January 8, 2007. and then, in the second, cucumber (Chuichong, Nongwoo Seed Co.) were cultivated in the same plastic house (sowing date : June 27, transplanting date : July 13). In the third, another cucumber cultivar (Jo-woon, Dongbu-hannong Seed Co.) were cultivated (sowing date : September 5, transplanting date : September 23). All of seedlings were transplanted on perlite bag ($W340{\times}L1,200{\times}H150mm$, 40L). By using this system, 971 boxes (5 kg/box) of tomato were produced and sold, and then total income was 5,466 thousand won per 10a. On the second cultivation, total amount of cucumber production was 489 boxes (50 ea/box), and total income was 7,380 thousand won. On the third cultivation, total amount of production was 67 boxes (100 ea/box), and total income was 1,854 thousand won. On the other hand, this system saved irrigated water by 50% ($4,000{\rightarrow}2,000L/10a/day$) in tomato cultivation, and by 44%($4,500{\rightarrow}2,500L/10a/day$) in cucumber cultivation. It also saved cost of nutrients by 50% in tomato ($1,648{\rightarrow}824thousand\;won/10a$), and 44% in cucumber ($1,648{\rightarrow}725thousand\;won/10a$). Furthermore this irrigation system maintained moisture content in perlite bag stable during cultivation period. Therefore, this system was successfully applied on farmer's greenhouse without a problem and can be commercialized for farmers.

• Journal of Bio-Environment Control
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• v.30 no.4
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• pp.367-376
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• 2021

Strawberry cultivation in Korea is grown in greenhouse, but most farms manage their water supply using a timer control method based on the experience of growers. The timer control has problems in that it is difficult to consider the weather condition, the growth stage of crops, and the moisture content of the substrate, so that the crops cannot be managed at an optimal level, and the accuracy of cultivation management are lacking. The watering methods using integrated solar irradiance and substrate moisture contents are control systems that provide eco-friendly and precise water supply considering the growth conditions of crops. The purpose of this study was to compare the combined water supply control with integrated solar irradiance and substrate moisture contents and timer control method in hydroponic cultivation of strawberries using coir, and to set the optimal integrated solar irradiance level for complex water supply control. The irrigation system was automatically watered when it reached 100, 150, 250 J·cm^-2 based on the external solar irradiance, and forced irrigation was performed at a substrate moisture content of less than 60% in all treatments. The amount of irrigation at once was 50 mL. The timer treatment was applied as a control. The smaller the level of integrated radiation to start watering, the greater the daily amount of irrigation. Both the fresh weight and dry weight per plant were higher in the complex irrigation control method than the timer control, and the 100 and 150 J·cm^-2 treatment had the highest fresh weight, and the 100 J·cm^-2 treatment showed a significantly higher dry weight. The yield was also significantly higher in the complex control method than in the timer, and the early yield increased as the level of integrated solar irradiance was smaller. The fresh weight of fruit was the lowest in the timer-controlled irrigation. As a result of this study, the possibility of combined control irrigation method using integrated solar irradiance and substrate moisture content was confirmed for precise water supply management of strawberries in hydroponics.

• Journal of Bio-Environment Control
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• v.21 no.1
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• pp.12-19
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• 2012

This research was performed to determine the appropriate daily last irrigation time to enhance the plant growth and the water and fertilizer use efficiencies in coir bag culture for tomato plant. The time to finish the daily irrigation was set by 1, 2, 3 and 4 hours before the sunset. The water content in the substrate was greatly affected by the last irrigation time. The earlier the last time, the greater the daily fluctuation of water contents in the substrate. The daily irrigation times were not affected by using irrigation management system controlled by drainage electrodes or the physiochemical properties of coir. The growth characteristics were not significantly different among the treatments. The highest marketable yields were obtained in the treatment finishing two hours before sunset, and the lowest yields were obtained in the the treatment finishing 4 hours before sunset. Based on the result from surveying quantity of irrigated water for 128 days of the experiment period, the water and fertilizer use efficiencies were lowest in the treatment finishing 4 hours before sunset, and the highest in the treatment finishing 2 hours before sunset. In terms of plant growth, yields, water and fertilizer use efficiencies, 2 hours before sunset treatment was determined as the most economical and desirable irrigation schedule.

• Journal of Bio-Environment Control
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• v.15 no.3
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• pp.225-230
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• 2006

Tomatoes were experimented in perlite bags for various irrigation control methods to elucidate the efficient method for nutrient solution management. The irrigation control methods were for 3 different types such as control by drainage level sensor (PROBE), control by integrated solar radiation (ISR), and control by time clock (Timer). The substrate weight was maintained stably in the proper range in PROBE treatment, regardless of daily solar radiations or growth stages. The bed weights in the treatments of ISR and Timer were changed largely. Growth as well as total yield was the highest in PROBE treatment. There was no difference in soluble solids (Brix %) among the treatments. Consequently, ISR control could be useful only with appropriate timer control and also calibration. Control by drainage level sensor was suggested to be the most satisfactory as irrigation management method.

• Journal of Bio-Environment Control
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• v.21 no.4
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• pp.317-321
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• 2012

This study was carried out to investigate the effect of EC levels in nutrient solution on the growth of rose in coir substrate during the juvenile. Nutrient concentration were EC 0.6, 1.0, 1.4, and $1.8dS{\cdot}m^{-1}$. In spite of high concentration of nutrient solution was supplied, EC and inorganic ions content in the extract of substrate was no difference by 22 days after planting. After that, they was rapidly increased with higher concentration of nutrient solution. Number of shoot was highest in EC $1.8dS{\cdot}m^{-1}$ at 2nd growth cycle, 90 days after planting, after that was showed a tendency to increase with increasing nutrient concentration, but was no significant difference among treatment except EC $0.6dS{\cdot}m^{-1}$. Judging by results of growth of rose and contents of inorganic ion in extracts of media, our experiment suggests that the suitable nutrient concentration is EC $1.8dS{\cdot}m^{-1}$ until 90 days and then EC $1.4dS{\cdot}m^{-1}$ until 165 days after planting that is more higher than conventional nutrient concentration for absorption by coir.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.58 no.4
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• pp.422-426
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• 2009

The key point on water culture is the precise irrigation control according to the growth condition of growing plant. And most existing irrigation controllers are operated independently. So, the manager must be resided at hydroponic farm. In this paper, we design the irrigation control system based on wireless Internet that can be providing various control functions according to the growth condition of growing plant by using the cellular phone.

• Horticultural Science & Technology
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• v.29 no.6
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• pp.568-574
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• 2011

Measuring tray as a component in irrigation control system using drainage electrodes was designed and applied for tomato perlite bed culture, and the effectiveness of the irrigation control system was investigated in terms of cultural development and cultivation costs. Five different types of measuring trays equipped with drainage electrodes were tested and the traditional tray was used as the control equipped with time clock. After the first experiment, "Tube-2" was removed because of instability of water content in the substrate. After second experiment, "Tube-1" was removed because of instability of water content in the substrate and low plant yields. In third experiment, "Up-Board" exhibited the best stability in water contents and yields as well as efficiencies in water and fertilizer utilization. The "Up-Board" was the most economical and the easiest system among the tested trays. Therefore, the "Up-Board" system was concluded as the excellent design to apply for the control method using drainage electrodes for tomato perlite bed culture.