• 생물환경조절학회지
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• 제2권2호
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• pp.99-109
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• 1993

Cooling of nutrient solution is essential to improve the growth environment of crops in hydroponic culture during summer season in Korea. This study was carried out to provide fundamental data for development of the cooling system satisfying the required cooling load of nutrient solution in hydroponic greenhouse. A numerical model for prediction of the cooling load of nutrient solution in hydroponic greenhouse was developed, and the results by the model showed good agreements with those by experiments. Main factors effecting on cooling load were solar radiation and air temperature in weather data, and conductivity of planting board and area ratio of bed to floor in greenhouse parameters. Using the model developed, the design cooling load of nutrient solution in hydroponic greenhouse of 1,000$m^2$(300pyong) was predicted to be 95,000 kJ/hr in Suwon and the vicinity.

• Journal of Biosystems Engineering
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• 제35권5호
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• pp.343-349
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• 2010

Rapid on-site sensing of nitrate-nitrogen and potassium ions in hydroponic solution would increase the efficiency of nutrient use for greenhouse crops cultivated in closed hydroponic systems while reducing the potential for environmental pollution in water and soil. Ion-selective electrodes (ISEs) are a promising approach because of their small size, rapid response, and the ability to directly measure the analyte. The capabilities of the ISEs for sensing nitrate and potassium in hydroponic solution can be affected by the presence of other ions such as calcium, magnesium, sulfate, sodium, and chloride in the solution itself. This study was conducted to investigate the applicability of two ISEs consisting of TDDA-NPOE and valinomycin-DOS PVC membranes for quantitative determinations of $NO_3$-N and K in hydroponic solution. Nine hydroponic solutions were prepared by diluting highly concentrated paprika hydroponic solution to provide a concentration range of 3 to 400 mg/L for $NO_3$-N and K. Two of the calibration curves relating membrane response and nutrient concentration provided coefficients of determination ($R^2$) > 0.98 and standard errors of calibration (SEC) of < 3.79 mV. The use of the direct potentiometry method, in conjunction with an one-point EMF compensation technique, was feasible for measuring $NO_3$-N and K in paprika hydroponic solution due to almost 1:1 relationships and high coefficients of determination ($R^2$ > 0.97) between the levels of $NO_3$-N and K obtained with the ion-selective electrodes and standard instruments. However, even though there were strong linear relationships ($R^2$ > 0.94) between the $NO_3$-N and K concentrations determined by the Gran's plot-based multiple standard addition method and by standard instruments, hydroponic $NO_3$-N concentrations measured with the ISEs, on average, were about 10% higher than those obtained with the automated analyzer whereas the K ISE predicted about 59% lower K than did the ICP spectrometer, probably due to no compensation for a difference between actual and expected concentrations of standard solutions directly prepared.

• 한국환경농학회지
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• 제24권1호
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• pp.24-28
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• 2005

본 연구에서는 시설하우스 폐양액이 고추의 생육과 양분 흡수에 미치는 영향을 평가하고 폐양액 관주시 부가적으로 얻을 수 있는 관개 효과를 산출함으로써 폐양액의 토양 시비에 따른 농업적 가치를 평가하였다. 시설하우스 폐양액의 토양 관주시 Ca, Mg K 등 염류의 증가로 인하여 pH와 EC는 상승하였고, 총질소는 암모늄태 질소와 질산태 질소의 증가와 함께 처리 후 100 mg $kg^{-1}$ 이상 증가하였다. 고추 생육은 화학비료 70% 및 폐양액 30% 혼합처리구와 화학비료 50% 및 폐양액 50% 혼합처리구에서 양호하였으며 양분 흡수도 동일한 경향을 나타내었다. 고추 수확량은 화학비료 70% 및 폐양액 30% 혼합처리구에서 가장 높은 것으로 조사되었다. 1일 발생되는 폐양액(288 L 10 $a^{-1}\;day^{-1}$)을 토양에 시용하여 증발산되는 수분을 보충할 경우 최고 $409.86m^2$의 면적을 관개할 수 있는 것으로 산출되었다. 이상의 결과를 통해 폐양액의 토양처리는 화학비료 대체 효과와 폐양액의 정화 효과를 동시에 얻을 수 있으며 적정량 시용시 주변 환경에 미치는 영향을 최소화하면서 지속적인 처리가 가능할 것으로 판단되었다.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2003년도 추계학술발표회
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• pp.102-106
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• 2003

The uptake of $^{14}C$-2, 4, 6-trinitrotoluene (TNT) in hydroponics was studied using onion plants. Of the total TNT mass (5 $\mu\textrm{M}$ concentration), 75% was in the roots, 4.4% in the leaves, and 21% in the external solution at 2 days, The percent distribution in roots was lower with higher concentration in the external solution, but in leaves it was comparable at all concentrations (5-500 $\mu\textrm{M}$). Root concentration factor (RCF) in hydroponics was more than 85 in constant hydroponic experiment (CHE) at 5 $\mu\textrm{M}$ and 150 in non-constant hydroponic experiment (NHE) at 5 $\mu\textrm{M}$. The maximum RCF values in the hydroponic system were greater with lower solution concentration. Transpiration stream concentration factor (TSCF) values in the present study (NHE only: 0.31-0.56) were relatively similar to the values with predicted values (0.43-0.78), increasing with higher external TNT concentration. For phytotoxicity tested in hydroponics and wet paper method, 500 $\mu\textrm{M}$ was toxic to onion plant, 50 $\mu\textrm{M}$ was non-toxic for plant growth but limited the transpiration rate, and 5 $\mu\textrm{M}$ was non-toxic as control.

• 한국식품조리과학회지
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• 제17권5호
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• pp.510-516
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• 2001

Hydroponic cultivation is a technology of raising crops without use of soil. Generally farmers use the method of DFT(deep flow technology)to grow leafy or fruity vegetables; however, systematic and scientific researches are insufficient on this matter. This study investigated the possibility of cultivating Chinese cabbage steadily year long by using the method of DFT. Chinese cabbage was cultivated hydroponically with and without Ge addition, used to prepare kimchi, and the chemical and microbiological characteristics of kimchi were compared. The basic hydroponic cultivation condition was as follows: 30 days after seeding, the raised seeds were moved to a hydroponic bed and given underground water for 3 days so the roots grow normally Standard nutrient solution was provided and the early electric conductivity concentration was maintained between 1.5∼2.5 thickness. The temperature of the solution was maintained between 10 ∼25$^{\circ}C$ to allow the growth of Chinese cabbage. When soil-cultivated, organically cultivated and hydroponically cultivated Chinese cabbages were compared, hydroponically cultivated cabbages were smaller in size and showed less ability to build up and fold leaves into a head, but showed better quality than organically cultivated cabbages. The contents of protein and fat showed no significant differences. The contents of water. Ca, P, Fe, Vitamin A and Niacin were higher in control and Ge-added cabbages compared with soil-grown cabbage. There was no difference between soil-cultivated Chinese cabbage kimchi and hydroponically cultivated Chinese cabbage kimchi.

• 한국환경복원기술학회지
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• 제11권5호
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• pp.1-11
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• 2008

This study was carried out to provide primary data set for cleaning of contamination site. By having hydroponic culture on Salix alba and S. caprea seedling treated with Ni solution, the result of Ni accumulation came out as followings : In a treatment of Ni to the Salix alba and S. caprea, Ni accumulation increased in its root, leaves, and stem, as Ni concentration became higher until $10.0{\mu}mol$. But in a $100.0{\mu}mol$ treatment, the seedlings died after 4 weeks. Ni accumulation in the Salix alba and S. caprea was the highest in its roots, second-highest in leaves, and the lowest in stems. In the case of $10.0{\mu}mol$ treatment of Ni solution, Ni accumulation in roots were above 500.0mg/L, and leaves were above 20.0mg/L. But it was lower than 13.0mg/L in stems. Ni accumulation in the plant increased more when nutrient solution containing Ni was weekly changed than just refilling the same amount of nutrient solution that evaporated Ni accumulation in Salix alba was higher than S. caprea when the nutrient solution had been refilled only.

• 한국농공학회지
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• 제36권3호
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• pp.113-121
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• 1994

Since it is difficult to expect the normal production of plants in greenhouses during hot summer season in Korea, certain provisions on the control of extreme environmental factors in summer should be considered for the year-round cultivation in greenhouses. This study was carried out to find a method to suppress the temperature rising of nutrient solution by cooling, which is able to contribute to the improvement of the plant growth environment in hydroponic greenhouse during hot summer season. A mechanical cooling system using the counter flow type with double pipe was developed for cooling the nutrient solution efficiently. Also the heat transfer characteristics of the system was analysed experimentally and theoretically, and compared with the existing cooling systems of nutrient solution. The cooling capacities of three different Systems, which used polyethylene tube in solution tank, stainless tube in solution tank, and the counter flow type with double pipe, were evaluated. The performance of each cooling system was about 41 %, 70% and 81 % of design cooling load in hydroponic greenhouse of 1 ,000m$^2$ on the conditions that the flow rate of ground water was 2m$^3$/hr and the temperature difference between two liquids was 10 ˚C According to the results analysed as above, the cooling system was found to have a satisfactory cooling capability for regions where ground water supply is available. Fer the other regions where ground water supply is restricted, more efficient cooling System should be developed.

• 한국환경농학회지
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• 제24권2호
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• pp.132-138
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• 2005

본 연구에서는 폐양액의 토양 처리에 따른 토양의 이화학적 특성 변화를 조사하고 혼합이온교환수지를 이용하여 토양 깊이에 따른 양분의 이동 및 농도 변화를 평가함으로써 폐양액이 토양에 미칠 수 있는 영향을 평가하고자 하였다. 폐양액을 토양에 처리한 경우 토양 중 $H^+$ 이온과 폐양액의 양이온이 교환되어 토양을 통과한 폐양액의 pH와 EC는 감소하였다. 컬럼 시험 결과 폐양액의 EC, 암모늄테 질소 및 $K^+$는 컬럼 길이가 길어질수록 감소하였고 관주 횟수가 증가할수록 제거율이 감소하였다. 이러한 현상은 폐양액 중의 양분이 토양층을 통과하며 양이온교환용량을 포화시켰기 때문이며 따라서 토양의 양이온교환용량과 염기포화도는 폐양액의 처리 효율과 처리용량을 결정하는 주요인으로 판단되었다. 질산태 질소의 경우 초기 폐양액 농도의 약 2/3 정도가 감소하였고 컬럼 길이보다는 관주 회수에 더 큰 영향을 받았다. 인산의 경우 제거효율이 높았으며 대부분이 고정화 혹은 침전 반응에 의한 것으로 판단되었다. 고추재배 포장에 폐양액을 처리한 경우 질소 및 인은 $NO_3-N>NH_4-N>PO_4-P$ 순으로 토양 용액에 존재하는 것으로 조사되었고 질산태 질소의 경우 45 cm 깊이에서도 농도가 높게 나타나 지하수로의 이동 가능성을 확인할 수 있었다. 따라서 질산태 질소의 경우 폐양액의 토양 처리를 제한할 수 있는 주요한 인자로 작용하는 것으로 사료된다. 인산의 경우 30 cm와 45 cm 모두에서 농도가 낮게 나타나 표층에서 대부분이 제거되는 것으로 확인되어 인산 이온이 지하수로 유입될 가능성은 매우 낮을 것으로 판단되었다.

• Journal of Plant Biotechnology
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• 제6권2호
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• pp.107-111
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• 2004

To establish an efficient acclimation system for regenerated plantlets of soybean, we used various media with hydroponic nutrient solutions before regenerants were transplanted into soil. The hydroponic nutrient solution was essential for the survival of the plantlets. The vermiculite with nutrient solution at pH 5.5 was found to be the best medium with 97-100% survival rate and better growth of regenerants plantlets. Regeneraed grew best in the following order of solutions: Yoshida solution, modified Yoshida solution, SoyI, Soy II, and MS medium. However, Soy I solution (EC 2.9 mS/cm), developed by the Honam Agricultural Research Institute proved to be the most effective for acclimation in terms of the time required for vigorous growth and economical use of chemicals.

• 유기물자원화
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• 제29권1호
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• pp.19-27
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• 2021

양액재배는 기존 비닐하우스 안의 토양재배 방식에서 물이나 배지에 작물을 심고 생육에 필요한 양분(비료)을 녹인 양액을 공급하여 재배하는 방식으로 기존 시설재배 방식에서 영농기술이 발전하여 양액재배는 작물의 생산성을 극대화할 수 있는 큰 장점을 가지고 있다. 본 연구는 폐양액이 다량의 비료 물질을 함유하고 있기에 하천으로 유입되면 인근 하천을 오염시키며, 양액재배에 사용되고 폐기되는 폐배지, 폐작물의 처리에 대한 문제점을 제시하고 있다. 또한, 처리시 처리비용의 발생과 현재 국내 양액재배 농장의 대부분이 비순환식 양액재배 시스템을 사용하여 배출되는 양액의 잔여비료로 인한 환경오염 및 비료의 불필요한 과다 사용 문제점을 지적하는 선행연구를 바탕으로 사전조사와 실험을 진행하였다. 현재 양약재배 비순환식 시스템 재배방식 농장에서 발생하는 폐양액, 폐배지, 폐작물이 농장 주변 환경에 미치는 영향을 수질, 토양분석 결과 수치를 통해 규명하고자 현장자료 연구를 진행하였다. 현장 수질, 토양분석을 위해서 지역별 양액재배 5개 농가의 작형, 양액재배 시스템를 확인하였으며, 강원 C지역 토경재배 3개 농장의 작형, 양액재배 시스템 농장 현장을 방문하여 농장의 시설내·외부 수질, 토양 샘플을 채취하였다. 추가적으로 폐작물 야적지에서 발생되는 침출수 및 토양샘플을 채취하여 수질, 토양분석을 하였다. 연구 결과 비순환식 시스템 재배방식 농장에서 발생되는 폐양액의 평균 total nitrogen(TN) 농도는 402 mg/L 이였고, total phosphate(TP)의 경우 77.4mg/L 이였으며, 이는 환경정책기본법 시행령상 하천의 생활환경 TP기준 993.7배 초과한 수치였다. 또한, 물환경보전법의 산업폐수 배출기준 TN기준 6~19배, TP기준 2~27배 초과한 수치결과를 확인하였다. 폐작물 야적지에서 발생된 침출수의 경우 환경정책기본법 시행령상 하천의 생활환경 COD 기준 11,828배 초과, TP기준 395~2663배 초과한 수치이며, 물환경보전법의 산업폐수 배출기준 TN기준 788배, TP기준 5배 초과한 수치결과를 확인하였다. 비순환식 양액재배에서 발생하는 폐양액, 폐배지, 폐작물이 환경에 미치는 영향에 대한 더 정밀한 연구를 위해 전국 양액재배 농가수(호), 재배면적(ha)를 기준으로 하여 양액재배면적이 넓은 지역 도출해내어야 한다. 이를 통해 넓을 지역의 양액재배 시설 주변 소하천을 중심으로 계절적 요인, 기후 요인, 날씨 요인, 재배면적, 재배지역, 농가 재배특성 등의 다양한 요인을 고려한 수질 및 토양 샘플링 채취와 분석에 관한 추가 연구가 필요할 것으로 판단된다.