• Horticultural Science & Technology
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• v.35 no.4
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• pp.456-464
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• 2017

We examined the effect of nutrient solution concentration in the second half of growing period on the pre- and postharvest characteristics of two leaf lettuce cultivars, 'Geokchima' and 'Cheongchima'. Plants were grown hydroponically in a deep flow technique (DFT) system at different concentrations of National Horticulture Research Institute hydroponic nutrient solution: 1/2 strength (S), 1S, 2S, and 4S. Lettuce leaf growth, number of leaves, and shoot fresh weight of both cultivars were greatest in plants grown in the 1S treatment. Compared to other treatments, pigment and nutrient ion contents were greater in the 4S treatment. Growth of lettuce was greatest in the 1S treatment, and decreased at higher or lower concentrations of nutrient solution. However, postharvest characteristics such as fresh weight loss, leaf chlorophyll level, and external appearance were better in both cultivars when grown in 2S solution. Variations in weight loss and SPAD values were smallest in the 2S treatment. These results show that the optimal nutrient concentration for growth does not necessarily provide the optimal postharvest storability.

• Journal of Bio-Environment Control
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• v.18 no.1
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• pp.46-50
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• 2009

This study was carried to investigate effects of optimum supply strengths of 'Sonneveld' nutrient solution on growth characteristics in container seedling of trees (Pinus densiflora, Torreya nucifera, Quercus acutissina and Fraxinus mandshurica) using developed media with used-rockwool. Flesh weight, height and trunk diameter in container seedling of Torreya nucifera were better in high strengths. In container seed ling of Torreya nucifera, flesh weight more increased in 1.5 and 3.0 strengths and hight and trunk diameter more increased in 1.5 strength than the rest. Flesh weight in container seedling of Quercus acutissina was heaviest in 2.0 strength and was lightest in 1.0 strength. Height and dry weight in 2.0 and 3.0 strengths and trunk diameter and total chlorophyll in 2.0 strength were better than in the rest. Besides photosynthesis rate was more high in 1.5 and 2.0 strengths than in the rest. In container seedling of Fraxinus mandshurica, flesh weight, height and trunk diameter more increased in 0.5 strength and total chlorophyll and photosynthesis rate were good in 0.5 and 2.0 strengths. Most growth characteristics were poor in 3.0 strength.

• Journal of Bio-Environment Control
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• v.6 no.4
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• pp.299-309
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• 1997

This experiment was conducted to determine the mineral absorption character and develop the optimum composition of nutrient solution for dill(Anethum graveolens L.) in hydroponics. Dill(Anethum graveolens L.) plants were grown in nutrient film technique(NFT) supplied with 1/4, 1/2, and 1 strength of the nutrient solution developed by National Research Station in Japan(HRS). Plants grown in 1/2 strength showed the best growth in plant height, fresh weight, and dry weight compared with those grown in 1/4 or 1 strength. In 1/2 strength solution, pH and EC changed little and proper nutrient contents were observed in the leaves as compared to plant nutrient diagnosis standard. Based on these results, optimum macronutrients were composed by nutrient- water absorption rate(n/w) with 1/2 strength: NO$_2$―N 8.85, NH$_4$―N 0.55, P 2.1, K 6.2, Ca 2.8, and Mg 1.7 me L$^{-1}$ To examine the suitability of the nutrient solution developed(SCU) , dill plants were grown in NFT supplied with two different kinds of solution and concentration. 1/2, 1, 3/2 and 25 of SCU and 1/2S of HRS. Changes of pH and EC were not distinct in 1S, but a significant change of pH was shown in low concentrations-HRS 1/2S and SCU 1/2S. Shoot fresh and dry weight were much higher in the plants grown in SCU IS as compared with HRS 1/2S. There were no significant differences in growth of plants grown in SCU IS, 3/2S, and 25. In addition, nutrient contents in the leaves grown by SCU 1S were in proper levels as compared with plant nutrient diagnosis standard. SCU 1S developed in this experiment was found to be optimum for dill in hydroponics.

• Journal of Bio-Environment Control
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• v.17 no.2
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• pp.162-169
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• 2008

To determine suitable composition of nutrient solution according to soil textures in fertigation culture of cucumber using three strengths (S) of Yamasaki cucumber recipe, chemical changes of soil, growth characteristics and yield of cucumber were investigated. Electric conductivity of drainage solution was risen in all treatments, pH of loam soil was generally optimum level and that of sandy soil was high level. Photosynthetic rate in loam soil supplied the 1/2 S and transpiration rate in sandy soil supplied the 1.0 S were most low. Diffusive resistance in sandy soil supplied the 1.0 S was high. Chlorophyll contents was higher concentrations by the kinds of soil. Amount of drainage solution in sandy loam soil supplied the 1/2 S and loam soil supplied the 1.0 S were most much and little, respectively. Water absorption rate was the opposition to amount of drainage solution. Nutrient contents in soil except calcium were most high in the 1.0 S by the kinds of soil. Nutrient contents in leaves, nitrogen in sandy soil supplied 1.0 S, phosphorus in loam soil supplied 1/2 S, potassium in two soil supplied 1.0 S, calcium in loam supplied 1/2 S and sandy loam soil supplied 1.0 S, magnesium in loam soil supplied the 1/2 S was high. The growth and yield of fruit were more in loam than in sandy loam soil. Therefore, the suitable compositions of macro-nutrients for fertigation culture of cucumber were determined in loam and sandy loam soils as follows: In loam soil, they were $NO_3$-N 12.3, $NH_4$-N 1.0, P 3.0, K 5.9, Ca 5.7, Mg $3.5\;me{\cdot}L^{-1}$, whereas in sandy loam soil $NO_3$-N 11.7, $NH_4$-N 1.0, P 3.0, K 5.9, Ca 4.9, Mg $3.2\;me\;L^{-1}$.

• Journal of Korean Society of Forest Science
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• v.98 no.3
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• pp.331-338
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• 2009

This present study was conducted to investigate photosynthetic characteristics, chlorophyll fluorescence, chlorophyll contents, and growth performances of containerized seedling and bare root seedling of Quercus acutissima growing under different fertilizing schemes. Both of containerized seedling and bare root seedling of Quercus acutissima showed good photosynthetic capacity and apparent quantum yield in the seedlings applied with one gram refining fertilizer (each of N, P, and K is 19%) diluted in one liter water. And chlorophyll contents also showed higher in the seedlings applied with the above fertilization scheme. The seedlings also showed good relative growth performances of root collar diameter, seedling height, total biomass, and leaf area in the some treatment scheme. In most of the treatments, containerized seedlings showed better photosynthetic capacity, apparent quantum yield, chlorophyll contents, and growth performances than bare root seedlings.

• Proceedings of KOSOMES biannual meeting
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• 2006.11a
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• pp.113-117
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• 2006

서해 남중부에 위치한 영광주변해역의 해양환경의 특성을 파악하기 위해 2006년 3월 25일과 7월 26일에 영광지역의 15개 지점과 비교를 위한 대조지역으로 변산반도 격포주변해역의 10개 지점을 선정하여 조사하였다. 대조지역에서는 수질관측결과 대체로 해역수질기준 $I{\sim}II$ 등급 수준의 양호한 결과를 보였으며, 영광지역의 수질은 해역수질기준 $II{\sim}III$ 등급으로 조사되었다. 수온의 경우 대조지역과 비교하여 훈계에는 $4{\sim}5^{\circ}C$를 하계에는 $2{\sim}3^{\circ}C$ 정도의 높은 값으로 조사되었다. 영광지역의 염분은 춘계가 하계에 비해 높게 나타났으며, 빠른 유속 특성을 보인 영광지역이 격포지역에 비해 두배가량 높은 부유물질량올 나타내었다. COD의 경우 영광지역은 평균 $II{\sim}III$등급을 보였고, 대조지역은 평균 $I{\sim}II$ 등급수준으로 나타났다. 영양염의 경우 해역수질등급과 비교하면 총질소 (TN)의 경우 영광지역은 춘계와 하계에 유사하게 평균 II 등급의 수질을 보였으며, 대조지역은 춘계에는 평균 I 동급의 수질을 하계에는 평균 II 등급의 수질을 보이는 것으로 나타났다. 총 인(TP)의 경우 통일한 시기에 유사한 농도분포로 지역별 차이는 보이지 않았고, 통일해역에서 하계에 상대적으로 높은 시기별 차이를 보였다. 국지적으로 III등급의 수질을 보인 곳도 있지만 대조지역의 하계 썰물 표층수가 평균 III 등급의 수질을 나타낸 것을 제외하면 거의 모든 조사시기에 평균 II 동급의 농도를 나타내고 있었다.sel. 2004년 2 월에 관측된 표층수온 분포값보다 2005년 2월에 관측된 표층수온 분포값이 상대적으로 낮은 분포 특성을 나타내고 있었다. 따라서 인공위성자료를 이용한 황해의 2004년 해황 분석 결과는 이상수온 상승의 원인이 쿠로시오 해류의 변통과 관련성이 높다고 판단되며 이에 대한 지속적인 연구가 현재 진행중에 있다.소처리에 인산염 처리, 여기에 초음파 처리, 마지막 단계로 3분 끓이면 억제율이 68%까지 억제되었다. 이는 단일처리시 전혀 억제를 못하는 처리를 단계별로 한 단계씩 더해가면 allergy 억제효과가 나타난다고 할 수 있겠다. 초음파 처리도 역시 저 allergy 처리 공정에 이용될 수 있는데 이것은 그 처리로 인해 새로운 알러젠이 생성될 수도 있다. 또한 복합처리로 allergy를 감소시키면 연속적이고 동시적으로 하기 때문에 원가를 절감할 수 있다.환경현안에 대한 정치경제적 접근을 외면하지 말고 교과서 저작의 소재로 삼을 수 있어야 하며, 이는 '환경관리주의'와 '녹색소비'에 머물러 있는 '환경 지식교육'과 실천을 한단계 진전시키는 작업으로 이어질 것이다. 이후 10년의 환경교육은 바로 '생태적 합리성'과 '환경정의'라는 두 '화두'에 터하여 세워져야 한다.배액에서 약해를 보였으나, 25% 야자지방산의 경우 50 ${\sim}$ 100배액 어디에서도 액해를 보이지 않았다. 별도로 적용한 시험에서, 토마토의 경우에도 25% 야자지방산 비누 50 ${\sim}$ 100배액 모두 약해를 발생하지 않았으나, 오이에서는 25% 야자지방산 비누 100배액에도 약해를 나타내었다. 12. 이상의 결과, 천연지방산을 이용하여 유기농업에 허용되는 각종의 살충비

• Journal of Bio-Environment Control
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• v.25 no.1
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• pp.49-56
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• 2016

This study was conducted to develop the disinfection system using electric shock for recycled nutrient solution in recycling soilless culture. Stainless steel (SUS 316) was found as the most appropriate electrode material for electrical disinfection system from the view of high electrical conductivity, low electric resistance, and low price. There were no changes in nutritional elements when the electric shock passed through the nutrient solution by stainless steel electrode. The amount of electric current increased with width than thickness of the electrode. The farther the distance between the electrodes was increased the time to reach out the aimed amount of current. The electric shock was applied to Ralstonia solanacearum and Fusarium oxysporum as representative bacteria and also fungi. Any of those pathogens were killed with the percentage of higher than 97% in the condition of 15VDC or 24VDC.

• Journal of Bio-Environment Control
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• v.17 no.2
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• pp.170-175
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• 2008

To verify suitability of the developed nutrient solution for fertigation culture of cucumber, chemical changes of soil, growth characteristics and yield of cucumber as affected by conventional fertigation method (Control), the developed nutrient solution for fertigation culture (DNF) and Yamasaki cucumber recipe (YCR) were investigated. At 48 days after transplant, photosynthetic and transpiration rate of cucumber leaves were the highest in 3/2 strength of DNF and 1/2 strength of YCR, but not different with the Control, in the later growing period photosynthetic rate was the highest in 3/2 strength of DNF and YCR and was clearly different with the Control, transpiration rate was the highest in 3/2 strength of DNF and 1/2, 1 strengths of YCR. The growth and yield of cucumber, nutrient elements of cucumber leaves except for calcium were more in DNF and YCR than in the Control. Compared with pre-treated loam soil, pH of the soil was low and electric conductivity was high in all treatments, amounts of accumulated phosphorus, potassium, calcium, and magnesium were much in the higher concentrations per the kinds of nutrient solutions. From the above results, it was considered that the developed nutrient solution has suitability as nutrient solution for fertigation culture of cucumber.

• Journal of Life Science
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• v.21 no.4
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• pp.584-588
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• 2011

This study was conducted to investigate the effects of organic materials, chitosan, wood vinegar, and EM active solution, on soil microbial and growth in Chinese cabbage. The organic materials were treated with chitosan, wood vinegar, and EM (effective microoganism) active solution, and the treatment concentration was 100 times solution and 1,000 times solution level with foliar application. The results are summarized as follows: Among foliar application of organic materials treatment plot[?], with 1,000 times solution level of chitosan was effective in inhibiting microbial growth in Chinese cabbage compared to other plots and control. The microorganism number in the soil for cultivation of Chinese cabbage increased with organic materials treatment plot as compared with control. Especially, 1,000 times solution level of chitosan showed the most significant effect.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.6
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• pp.1300-1305
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• 2011

The study was conducted to investigate the characteristics of flower quality and yield of gerbera 'Sunny Lemon' by mutrient solution strength and media of nutrient solution. The plant growth of 'Sunny Lemon' showed the highest values in the media of rockwool and perlite 1: peatmoss 2. Especially the yield of cut flowers for a year was more than 60 flowers and the flower longevity was over 10 days irrespective of nutrient solution concentration in the two media. There were no significant differences of plant characteristics in the nutrient concentration of 1/2 and 1 times, and the mineral nutrient contents showed similar values. Therefore, we recommended the media of perlite1: peatmoss2 with the concentration of 1/2 times for economical use. The rockwool media was not appropriate because of the weak buffer capacity like EC and pH.