• 한국토양비료학회지
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• 제48권1호
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• pp.30-35
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• 2015

This study was conducted to investigate investigated the effect of nitrogen fertilizer on nitrate concentration in soil solution and to determine the relationship between yield and nitrate concentration in soil solution for cucumber cultivation under plastic film house. Nitrogen as urea was applied at rates of 0, 120, 240, 360, and $480kg\;N\;ha^{-1}$ as an additional fertilizer by trickle irrigation during cucumber cultivation. Monitoring of nitrate concentration in soil solution was investigated using porous cups at 25 cm depth under soil surface. Nitrate concentration in soil solution increased with increasing the rate of additional nitrogen. Correlation coefficient between EC value and nitrate concentration was positive in soil and soil solution (p<0.05). An additional nitrogen of about $300kg\;ha^{-1}$ was shown the highest yield of cucumber, and improved yield by 5% compared to N recommendation of $240kg\;N\;ha^{-1}$. The highest yield was determined at nitrate concentration of $82mg\;L^{-1}$ in soil solution by regression equation ($Y=74.2+0.73X+0.000504X^2$, $R^2=0.629^*$). These results means indicate that nitrate concentration in soil solution would be useful method to rapid determination for additional nitrogen during cucumber cultivation under plastic film house.

• 한국토양비료학회지
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• 제43권1호
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• pp.68-74
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• 2010

담수상태의 토양이나 습지생태계에서 ${NO_3}^-$는 환원상태의 발달을 지연시키는 완충역할을 할 수 있다. 논토양에서 관개용수를 통하여 공급되는 ${NO_3}^-$가 Fe의 환원과 그에 따른 P의 가용화에 미치는 영향을 조사하였다. 관개용수중의 ${NO_3}^-$ 함량이 5 mg N $L^{-1}$ 수준일 경우 5 cm 깊이 토양에 도달하기 전에 대부분 탈질작용에 의해 제거되었으며, 5 cm 깊이 토양에서 일어나는 Fe의 환원과 P의 용출이 저해되었고 10 cm 깊이 토양의 환원현상에는 영향을 미치지 못하였다. ${NO_3}^-$ 함량이 10 mg N $L^{-1}$ 수준인 관개용수를 공급하였을 경우에는 10 cm 깊이 토양층까지 ${NO_3}^-$가 잔류 유입되었으며, Fe의 환원과 P의 용출을 현저히 억제하는 것으로 나타났다. 이상의 결과를 보면 관개용수를 통하여 ${NO_3}^-$를 포함한 질소가 과도하게 논토양으로 유입되면 질소과다현상을 유발할 뿐만 아니라 P의 가용화를 억제함으로써 인 결핍을 초래할 수도 있을 것이다.

• 생물환경조절학회지
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• 제12권1호
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• pp.7-11
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• 2003

본 실험은 폐기된 유리물질을 재가공하여 입자화한 CGF(cellular glass foam)를 펄라이트 대체 혼합상토로 이용하기 위하여 수행되었다. CGF의 입자크기를2.0∼4.0 mm로 조절한 후 피트모스와 혼합하여 배지를 조제하였고 관수빈도에 따른 Lycopersicum esculentum 'Segye' 플러그묘의 생육을 비교히였다. CGF와 피트모스의 혼합비율은 25：75와 33：67(%, v/v)이였으며 관수빈도는 2일에 1회, 2회, 또는 3회로 하였고, 상업용 플러그 배지(토실이 배지)에 1일 I회 관수한 것을 대조구로 하였다. 파종 후 33일에 플러그묘의 초장, 경경, 줄기와 뿌리의 생체중과 건물중, 엽수, 엽면적, 엽록소 함량, 그리고 배지의 pH와 EC를 조사하였다. 배지 혼합비율에 따른 플러그묘의 전체 생육은 유의성이 낮았다. 관수빈도에 따른 경경, 엽수, 엽면적, 줄기와 뿌리의 생체중과 건물중, T/R 그리고 배지의 EC에서 유의적인 차이를 보였다 CGF와 피트모스를 25：75(%, v/v)로 혼합한 배지에 관수빈도를 높인 처리에서 묘의 생육이 가장 좋았다.

• 한국관개배수논문집
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• 제13권1호
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• pp.39-49
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• 2006

Weather station based PET(Potential Evapotrarspiration) analysis has often been inadequate to meet the needs of regional-scale irrigation planning. A map of continuous PET surface would be better a solution for the spatial interpolation considering spatial variations. Using a normal PET data collected at the 54 meteorological stations in Korea, 10-days spatial distribution PET map was created using universal Kriging(UK). These estimation methods were evaluated by both visual assessments of the output maps and the quantitative comparison of error measures that were obtained from the cross validation. The universal Kriging method showed appropriate results in spatial interpolation from weather station based PET to spatial PET with low statistical errors.

• 원예과학기술지
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• 제16권1호
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• pp.37-39
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• 1998

본 연구는 절화용 국화의 펄라이트 배지경 양액재배시, 국화의 생육과 절화 품질에 적합한 양액의 농도와 관주주기에 대한 기초 자료를 얻고자 실시되었다. 양액재배와 토양재배를 비교하였을 때, 초장은 양액재배에서 더 길어 절화의 품질은 좋았으나 엽내 무기이온의 함량은 두 재배간에 별 차이가 없었다. 양액재배시 국화의 생육과 개화에 있어 최적 농도를 규명하기 위해 화란 국화전용양액의 1/2, 1, 2배액을 처리한 결과, 유묘기에는 1/2배액처리도 양호하였으나 생육이 진전됨에 따라서 꽃의 생체중과 건물중이 낮은 반면, 1배액은 초장도 가장 길고 생육도 좋았다. 각 기관별 무기이온의 함량에 있어서는 뚜렷한 차이는 없었지만, 1/2 배액처리에서 전질소와 $NO_3-N$ 함량이 적었으며 2배액에서는 전질소 함량이 1배액보다 작을 뿐 큰 차이가 없었다. 또한 최적 관주주기를 구명하기 위해 양액을 하루에 2, 4, 8회로 나누어서 관주한 결과, 1배액 8회/일 관주에서 배지내 함수율 및 수분 이용율의 증대, 근권부의 신속한 양분교체로 인하여 생육이 가장 좋았다. 관주주기에 따른 각 기관별 무기이온함량에 있어서는 전반적으로 8회 관주가 높은 경향을 보였다. 국화의 양액재배시 양액농도와 관주주기가 국화의 절화수명에 미치는 영향을 살펴본 결과, 양액농도에 따라서는 큰 유의성이 없었지만 1배액이 2배액보다는 2-3일 정도 길었고, 관주주기에서는 하루 2회 관주가 4회와 8회 관주보다는 절화수명이 5일 정도 길었다.

• 원예과학기술지
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• 제29권6호
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• pp.568-574
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• 2011

토마토 펄라이트 베드재배에서 급액방법으로 배액전극 제어법을 적용하기 위한 적정 측정틀 개발을 위해 본 실험이 수행되었다. 작물로는 대과종 토마토를 사용하였고, 재배 방법은 자루재배와 동일하게 적용하였으며, 급액제어 방법으로 배액전극 제어법을 적용한 다섯 가지 측정틀 처리와 타이머 제어법을 적용한 한 가지 측정틀 처리를 대조구로 하였다. 1차 실험에서는 배지의 수분함량 안정성 조사로 가장 불안정한 Tube-2 처리를 제외하였고, 2차 실험에서는 배지의 수분함량 안정성과 생육과 수확량을 조사하여 성적이 가장 나빴던 Tube-1 처리를 제외하였다. 3차 실험에서 배지의 수분함량 안정성과 생육 및 수확량에서 우수하였으며, WUE와 FUE가 가장 높았던 Up-Board 처리를 선택하였다. Up-Board 처리는 여섯 가지 처리 중에서 가장 경제적이며 측정틀 제작도 용이하여 베드충진 방식에서 배액전극 제어법을 적용하기에 가장 우수한 측정틀 설계였다.

• 한국물환경학회지
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• 제20권3호
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• pp.301-306
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• 2004

The present water quality standards for agricultural were established without considering the effects of water quality on the safety, growth, yield and quality of crops. This study was carried out to investigate the effects of irrigation water quality on the growth, yield, and grain quality of rice, and to acquire basic knowledges to set up water quality standards for irrigation. The field and pot experiments were conducted with irrigation water that was previously adjusted four concentrations (control, 5, 10, 20 mg/L) and six concentrations (control, 5, 10, 15, 20, 30 mg/L) by $NH_4NO_3$ solution and replicated three and four times with randomized block design, respectively. The results of this study showed that the inorganic nutrient of rice plant, rice protein contents and number of panicle tended to increase as the T-N concentration in irrigation water was increased. In addition, grain yield at T-N 10 mg/L and 20mg/L were significantly higher than the control at the field experiment. From the pot experiment at T-N 30 mg/L, the percentage of head rice was slightly lower due to the increase of green kernel and white belly/core kernel.

• Journal of Periodontal and Implant Science
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• 제54권3호
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• pp.149-160
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• 2024

Purpose: The objective of this retrospective clinical study was to provide evidence supporting the adjunctive local application of doxycycline solution or minocycline ointment, in conjunction with drainage, for the treatment of acute periodontal abscesses. Methods: The study included 63 patients who had received treatment for acute periodontal abscesses through drainage supplemented with 1 of 3 types of adjunctive medications during their initial visit (visit 1; baseline): 1) saline irrigation (the control group), 2) 2% minocycline ointment (the TM group), or 3) 300 mg/mL doxycycline irrigation (the TD group). The same adjunctive medication was administered at visit 2, which took place 1 week after visit 1. Probing depth (PD), bleeding on probing (BOP), plaque index, gingival recession, clinical attachment level, and tooth mobility were clinically evaluated at visits 1, 2, and a third visit (visit 3; 4 weeks after visit 1). Statistical significance was considered to be indicated by P values <0.05. Results: By visit 3, all clinical indices and tooth mobility had significantly decreased in each group. At this visit, PD and BOP on the abscess side were significantly lower in the TM and TD groups compared to the control group. The TD group showed a significantly greater improvement than the TM group, with mean PD reductions of 1.09 mm in the control group, 1.88 mm in the TM group, and 2.88 mm in the TD group. Similarly, mean BOP reductions were 45% in the control group, 73.02% in the TM group, and 95.45% in the TD group. Conclusions: Local and adjunctive administration of doxycycline and minocycline in combination with drainage exhibited clinical advantages over drainage alone in improving PD and BOP. Notably, a doxycycline solution of 300 mg/mL was more effective than a 2% minocycline ointment.

• 생명과학회지
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• 제9권6호
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• pp.665-670
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• 1999

The effects of media, cell sizes and fertilizers on the early growth of Phalaenopsis plug plants were investigate. The sphagnum moss was more effective than other media in pink and white color cultivars. In comparison of different plug cell size, 50 cell size was more effective then 72 and 128 cell size in pink and white cultivar. In comparison of different fertilizer, margamf K in pink, and nutrient solution II(one time drenching with NHRI standard solution for three times irrigation) in white color cultivars was more effective then others, respectively.

• 한국농공학회지
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• 제29권3호
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• pp.125-137
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• 1987

The purpose of this paper is to examine some difficulties in water management of agricultural reservoirs in Korea, for there are approximately more than 15,000 reservoirs which are now being utilized for the purpose of irrigation, along with the much amount of expenses and labors to be invested against droughts and floods periodically occurred. Recently, the effective use of water resources in the agricultural reservoirs with a single purpose, is becomming multiple according to the alterable environment of water use. Therefore, the task to allocate agricultural water rationally and economically must be solved for the multiple use of agricultural reservoirs. On the basis of the above statement, this study aims at suggesting the rational method of water management by introducing an optimal technique to allocate the water in an existing agricultural reservoir rationally, for the sake of maximizing the economic effect. To achieve this objective, a reservoir, called "0-Bongje" as a sample of the case study, is selected for an agricultural water development proiect of medium scale. As a model for the optimum allocation of water in the multi-purpose use of reservoirs a linear programming model is developed and analyzed. As a result, findings of the study are as follows : First, a linear programing model is developed for the optimum allocation of water in the multi-purpose use of agricultural reservoirs. By adopting the model in the case of reservoir called "O-Bongje," the optimum solution for such various objects as irrigation area, the amount of domestic water supply, the size of power generation, and the size of reservoir storage, etc., can be obtained. Second, by comparing the net benefits in each object under the changing condition of inflow into the reservoir, the factors which can most affect the yearly total net benefit can be drawn, and they are in the order of the amount of domestic water supply, irrigation area, and power generation. Third, the sensitivity analysis for the decision variable of irrigation which may have a first priority among the objects indicate that the effective method of water management can be rapidly suggested in accordance with a condition under the decreasing area of irrigation. Fourth, in the case of decision making on the water allocation policy in an existing multi-purpose reservoir, the rapid comparison of numerous alternatives can be possible by adopting the linear programming model. Besides, as the resources can be analyed in connection with various activities, it can be concluded that the linear programing model developed in this study is more quantitative than the traditional methods of analysis. Fifth, all the possible constraint equations, in using a linear programming model for adopting a water allocation problem in the agricultural reservoirs, are presented, and the method of analysis is also suggested in this study. Finally, as the linear programming model in this study is found comprehensive, the model can be adopted in any different kind of conditions of agricultural reservoirs for the purpose of analyzing optimum water allocation, if the economic and technical coefficients are known, and the decision variable is changed in accordance with the changing condition of irrigation area.