• Journal of Bio-Environment Control
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• v.21 no.3
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• pp.228-235
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• 2012

This study was carried out to investigate the effect of irrigation methods for reducing a drainage on the growth and yield in rockwool (Grodan co.) and cocopeat (chip : dust = 50 : 50 included fiber) culture. The nutrient solution was irrigated by $100J{\cdot}cm^{-2}$-100 mL, $50J{\cdot}cm^{-2}$-45 mL, $50J{\cdot}cm^{-2}$-40 mL, $50J{\cdot}cm^{-2}$-35 mL ($100{\sim}50J{\cdot}cm^{-2}$-100~35 mL, Nutrient solution 100~35 mL was irrigated per plant when the accumulated radiation was $100{\sim}50J{\cdot}cm^{-2}$). The drain rates per plant of 100-100, 50-45, 50-40, 50-35 were 26.3%, 8.8%, 6% 4.4% and 23.1%, 7.5%, 5% 3.4% in rockwool and cocopeat slabs. The water contents and EC of 100-100 and 50-45 were managed by the 55~70%, $3.0{\sim}5.0dS{\cdot}m^{-1}$ which were good condition for paprika culture in rockwool and cocopeat slabs, while those of 50-40 and 50-35 were managed by beyond 50%, $4.5{\sim}9.5dS{\cdot}m^{-1}$. The plant height, number of branches and leaf size of 100-100 and 50-45 were similarly increased while those of 50-40 and 50-35 were decreased. The fruit size and weight of 50-40 and 50-35 were small and light, while those of 100-100 and 50-45 were similarly big and heavy. The marketable fruits of 100-100 and 50-45 treatments were similarly more by 9.7~9.8 in rockwool and 8.8~8.9 in cocopeat, while the unmarketable fruits, the small and blossom end rot fruits were increased in 50-40 and 50-35 treatments. The yield of 100-100 and 50-45 treatments were similarly high.

• Journal of Bio-Environment Control
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• v.13 no.3
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• pp.125-129
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• 2004

This study was conducted to identify the growth characteristics of melon cultivated with mixture medium of scoria and perlite in capillary system. The growth and fruit characteristics of all cultivars cultivated under the nutrient solution capillary supplying system were comprehensively favorable. Fresh fruit weight of the three cultivars was similar to weight criterion (1.8 - 2.0 kg/fruit) of melon. In melon of non-net type ‘Aris’ there were no differences in fruit characteristics between nutrient solution supply methods, but total soluble solid (TSS) was higher in drip and capillary systems showing $15.6^{\circ}$Brix and 15.5$^{\circ}$Brix, respectively, than that of mist spray system showing $14.4^{\circ}$Brix. In melon of net type, ‘Earl's elite’, drip and capillary systems showed better fruit characteristics and higher values of TSS compared to mist spray system. The change in pH in the medium before and after melon cropping was not significant between systems, but the pH of upper layer within medium in all system was higher than that of lower layer. The mineral content within lower layer showed higher value than that of the upper layer in drip system, but reversed in capillary system.

• Journal of Bio-Environment Control
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• v.12 no.2
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• pp.77-82
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• 2003

The effect of the particle size of perlite and irrigation amount on the growth, root activity and mineral competition of tomato was investigated in a recycling system. The particle sizes used were small (SPP, øl∼2 mm), medium (MPP, ø2∼3 mm), (LPP. ø4∼5 mm). Plant height, fresh weight and dry weight of tomato at the earlier growth stage were good at 3.0 L/day in MPP and LPP, but these were not significantly affected by irrigation amount in MPP, Fruit number, weight and yield increased at 1.5 L/day in SPP and 3.0 L/day at MPP or LPP, Deformed fruits tended to increase at higher irrigation amounts regardless of particle size. Root activity increased with increasing particle size with higher irrigation amount during early stage after transplanting, but remarkably decreased at 3.0 L/day in SPP as compared with the others at 100 days. Mineral contents of plants after harvest were higher at MPP and LPP than SPP, but were highest at 3.0 L/day in LPP. In conclusion, it was regarded that tomato growth in a recycling system was optimal at MPP or LPP with irrigation amount of B.0 L/day.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 1998.10a
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• pp.24-27
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• 1998

최근 급속히 신장하는 양액재배로부터 파생되는 배양액의 배출과 고형배지의 폐기에 의한 환경 오염을 최대한 억제하면서 지속적으로 안전한 생산물을 공급하는 것은 매우 중요한 작업이다. 현재 구미각국에서도 가장 널리 이용되고 있는 암면 배지에 의한 환경오염이 문제시됨에 따라 이를 대체할 수 있는 배지의 개발이 활발히 진행되고 있다. (중략)

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 1997.05a
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• pp.62-64
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• 1997

작물생육은 근권 부근의 온도와 밀접한 관계가 있다. 따라서 외부환경의 영향을 받기 쉬운 단순 경량화된 순환형 무토양재배시스템내의 양액 또는 배지의 온도 변화를 파악하여 환경조절을 통한 적정 생육환경을 조성할 수 있다면, 작물의 생산성에 기여할 수 있다. 본 연구는 순환식 무토양재배시스템의 위치별 온도 분포 및 배양액의 공급 과 온도변화와의 관계를 분석하였다.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1999.12a
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• pp.284-291
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• 1999

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1998.12a
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• pp.201-207
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• 1998

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 1994.11a
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• pp.76-77
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• 1994

양액재배는 근권의 완충력이 낮기 때문에 작물의 양수분흡수에 필요한 근권환경 조성에 세심한 주의가 필요하다. 양수분 공급이 용이하고 근권완충력도 뛰어난 고형배지의 개발이 최근 활발하게 진행중이며, 현재 가장 많이 사용되고 있는 락을의 폐기시 환경문제가 대두됨에 따라서 다양한 대체배지의 이용가능성이 검토되고 있다. 그러므로 본 실험은 토양, 펄라이트, 왕겨, 피트모스 등의 고형배지를 고형배지를 단용 또는 혼용으로 처리하여근권의 배지종류가 멜론의 생육 및 과실생장에 미치는 영향을 구명하고, 멜론 양액재배시 멜론생육에 적합한 배지를 개발하기 위한 기초자료로 활용하고자 본 실험을 수행하였다. (중략)

• Journal of Bio-Environment Control
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• v.26 no.4
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• pp.393-401
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• 2017

The nitrate ($NO_3{^-}$) accumulation of hydroponically grown leafy vegetables may increase in the condition of a closed-type plant production system with low light intensity due to low activity of enzymes involved in nitrogen assimilation and the use of $NO_3-N$ as major nitrogen source. The objective of this study is to investigate the effects of light intensities, nutrient solution compositions and the time of nutrient solution removal before harvest on nitrate contents of hydroponically-grown lettuces in a closed plant production system. The reduction of nitrate contents in leafy lettuces 'Cheongchima' was higher in the treatments of 'TW' (nutrient solution removal) and '$(NH_4)_2CO_3$' (use of ammonium carbonate as nitrogen source) than those in other treatments, which significantly lowered fresh weight and leaf area of the plants. In the light intensity of $100{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, the nitrate content was effectively reduced without causing any growth retardation, by substitution of the nutrient solution composition that $NO_3-N$ was removed ('$NO_3-N$ removal' treatment) or the half strength of standard nutrient solution was applied ('1/2 S' treatment), for 7days before harvest. The effects of light intensity and the time of nutrient solution removal before harvest on growth and nitrate contents in leafy lettuces were investigated. The nitrate contents in leaves under the light condition of $300{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ before nutrient solution removal were lower than those of 100 or $200{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$. The removal of nutrient solution for 7 days before harvest quickly reduced the amount of nitrates in leaves in all the light intensities with a greater degree under the $300{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ of light condition, while the 7 days-removal with both 200 and $300{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ of light conditions caused decrease in 16~31% of leaf area and 20~35% of fresh weight, compared to the 3 days-removal treatment. The nitrate contents were greatly reduced from 3,018 to 1,035 in $200{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, and 2,021 to 480 ppm in the light condition of $300{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, with the nutrient solution removal for 3 days before harvest, without causing any deterioration in growth and product quality. The vitamin C contents in leaves were higher in the treatment of nutrient solution removal for both 3 and 5 days before harvest with the light condition of $300{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ than those in the light condition of 100 or $200{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$.

• Journal of Bio-Environment Control
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• v.30 no.4
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• pp.271-277
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• 2021

In this study, experiments of local heating on crown and supplying warm nutrient for energy saving and improving growth of 'Seolhyang' strawberry were conducted. The temperature of inside and crown in greenhouses which were control (space heating 8℃) and test (space heating 5℃+crown heating) was measured. In the control greenhouse, the average of temperature and humidity in December was 7.1℃, 87.2%, respectively. In the test greenhouse, the average of temperature and humidity in December was 5.7℃, 88.7%. The temperature of crown and inside the bed were 7.9℃, 10.8℃ in control, 9.3℃, 12.7℃ in test. During the test period, the total 16,847×10³ kcal of energy was consumed in control greenhouse including space heating. In test greenhouse including space heating, crown heating and warm water supplying, total 9,475.7×10³ kcal of energy was consumed. So, energy consumption in test was 43.8% less than in the control. The total yields of strawberry during test period were 412.7g/plant for test greenhouse and 393.3g/plant for control greenhouse respectively.