• Plant Resources
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• v.2 no.1
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• pp.26-30
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• 1999

Nitrate in edible vegetables is converted to nitrite by nitrate reductase(NR) and/or bacteria in intestines. Nitrite and amino, in the intestine of some animals and human, bind to form nitrosamine, which is toxic and known as carcinogen. This study was carried out to examine the effect of added chlorides and their concentrations on growth, yield and nitrate content in leaf lettuce plants in hydroponics. Seeds of lettuce cv, "Samsunjokchukmyon" were planted on April 29, and seedlings were planted on June 2, and were cultured until July 5 in 1998. KCI and CaCl₂ were used as chloride source and their concentrations were 1, 2 and 4 me/L, respectively, in the lettuce standard nutrient solution for National Horticultural Research Institute(NHRI). Completely randomized design with 3 replications was used. Nitrate content and NR activity were measured 2 and 5 weeks after planting(WAP). The obtained results were summarized as the follows : Leaf weight per plant was difference from harvest dates and treatments, but total leaf weight was not significantly different among treatments. Number of leaves was higher in KCI 2 me/L, CaCl₂1 me/L and control at 2 WAP than the others, and was higher in KCI 1 me/L, and control at 3 WAP than others, and was higher in control at 5 WAP. Total number of harvested leaves was the highest in control with 14, which followed by KCI 2 me/L and CaCl₂1 me/L. Nitrate content was decreased by addition of chloride in nutrient solution. Nitrate content in the 3rd and 9th leaves was significantly decreased. NR activity was higher in control and CaCl₂ addition treatments, while KCI addition treatments reduced NR activity. However, no direct relationship with nitrate was observed. Growth characteristics such leaf length and leaf width were not significantly influenced by chloride addition.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.27 no.2
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• pp.43-53
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• 2024

This study attempted to elucidate the ecological niches and influencing environmental factors of Quercus variabilis and Quercus acutissima, which are representative deciduous broad-leaved trees in Korean forests, taxonomically close and genetically similar, under climate change conditions. Under climate change conditions induced by increased CO₂ and temperature, soil moisture and nutrient environments were manipulated in four gradients. At the end of the growing, plants were harvested to measure growth responses, calculate ecological niches, and compare them with those of the control. Eperimental plants were grown for 180 days in a glass greenhouse designed with four gradients each for soil moisture and nutrient environments under climate change conditions induced by increased CO₂ and temperature. After harvesting, growth responses of leaf traits were measured, ecological niches were calculated, and these were compared with those of the control groups. Furthermore, the responses of the two species' populations were interpreted using principal component analysis(PCA) based on leaf trait measurements. As a result, under climate change conditions, the ecological niche breadth for moisture environment was broader for Quercus variabilis than Quercus acutissima, whereas for the nutrient environment, Quercus acutissima exhibited a broader niche breadth than Quercus variabilis. And the rate of change in ecological niche breadth due to climate change decreased for Quercus variabilis in both moisture and nutrient environments, while for Quercus acutissima, it increased in the moisture environment but decreased in the nutrient environment. Additionally, in terms of group responses, both Quercus variabilis and Quercus acutissima expanded their ecological niches under climate change conditions in both soil moisture and nutrient conditions, with Quercus acutissima exhibiting a broader niche than Quercus variabilis under nutrient conditions. These results indicate that the changes in leaf morphological characteristics and the responses of individuals reflecting them vary not only under climate change conditions but also depending on environmental factors.

• Journal of Bio-Environment Control
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• v.1 no.2
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• pp.154-161
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• 1992

This experiment was carried oui to determine the relativeness between growth, yield characters and bio-informations as influenced by the spray and rest time intervals of nutrient solution. Tomato(Lycopersicon esculentum Mill.) were grown in aeroponic system on a misting schedule of continuously 60 sec, 30 sec and 10 sec at 10 min intervals with full strength Yamazaki's solution recommended for tomato production. The results obtained were as follows : 1. Leaf area was highest in the plot of 30 sec spray and 10 min rest while the forest one was the plot of 60 sec spray and 10 min rest. Growth characteristics in terms of dry weight of each organ, number of flower, number of flower setted and fruit dry weight were greater in the plot of 30 sec spray and 10 min rest than the other treatments. 2. The number of flower increased with decreasing dry weight but number of flower sorted was not significantly different among treatment except for the plot of 60 sec spray and 10 min rest. 3. Leaf dry weight and fruit dry weight were highly correlated so that 30 sec spray and 10 min rest plot which is the highest fruit dry weight showed the largest leaf area. Continuously sprayed plot reduced markedly the fruit dry weight compared with leaf area. Optimum spray and rest time of nutrient solution in the range of this experiment was determined as 30 sec spray and 10 min rest. 4. Solar radiation within glasshouse during daytime reduced severely compared with outdoor one and air temperature within greenhouse was higher than the leaf temperature of tomato plant. The changes of environmental factors, solar radiation, temperature were accompanied with the sensitive change of bio-informations of tomato leaf Especially differences of spray intervals of nutrient solution affected greatly to the changes of bio-informations : leaf water potential, stomatal resistance and leaf temperature etc. 5. The changing patterns of leaf growth as influenced by the spray and rest intervals of nutrient solution were closely related to the leaf water potential, stomatal resistance and leaf temperature. Feasibility was demonstrated that measurement of bio-information of tomato leaf as influenced by the change of environmental factors could be expected to the amount of growth and fruit yield.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.46 no.1
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• pp.1-5
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• 2001

Field experiment was conducted during 1993-94 season to determine the pattern of nutrient uptake and productivity of maize/sweet potato intercropping system. Four levels of nitrogen (0, 50, 100 and 150kg N ${ha}_{-1}$) and four levels of potassium (0, 40, 80 and 120kg $K_2$O ${ha}_{-1}$) formed treatment variables. Plants were sampled periodically to determine dry matter and tissue concentrations of N and K in the individual plant components of intercropped maize and sweet potato. Nitrogen and potassium fertilizer did not interact significantly to nutrient uptake by any plant parts of intercropped maize and sweet potato. But application of N fertilizer independently enhanced N uptake in all the plant parts of maize and sweet potato. The uptake of N in leaf, leaf sheath, stem, husk, and cob of maize increased upto 90 days after planting (DAP) but grain continued to accumulate N till its maturity. Sweet potato exhibited a wide variation in N uptake pattern. Sweet potato leaf shared the maximum uptake of N at 50 DAP which rapidly increased at 70 DAP and then declined. Declination of N uptake by petiole and stem were observed after 120 DAP whereas N uptake by tuber increased slowly upto 90 DAP and then rapidly till harvest. Rate of applied K had very little effect on the uptake patterns in different components of intercropped maize. Pattern of K uptake by leaf, petiole and stem of sweet potato showed almost similar trend to N uptake. But uptake of K by tuber increased almost linearly with the K application. Pattern of N and K uptake by grain and tuber paralleled the grain yield of maize and sweet potato respectively. Intercropped productivity of maize and sweet potato found to be better by the application of 100kg N and 120 kg $K_2$O ${ha}_{-1}$

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.6
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• pp.1137-1143
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• 2011

Optimum soil management of chestnut orchards is important to ensure high quality and yields of chestnut. This study was conducted to evaluate soil and green leaf characteristics by establishment periods of chestnut (Castanea crenata Sieb. et. Zucc.) orchards in Sancheong-gun, Gyeongsangnam-do. Total 30 plots with the criteria of similar cultivation practices were chosen and classified into two establishment periods by over 20-year-old orchards (17 plots) and below 19-year-old orchards (13 plots). Soil bulk density was significantly higher (p<0.05) in over 20-year-old ($1.16g\;cm^{-3}$) than in below 19-year-old ($1.03g\;cm^{-3}$) plots. Soils in over 20-year-old plots were severely acidified with pH 4.56 compared to pH 4.73 in below 19-year-old plots. However, soil organic matter, total nitrogen, available phosphorus, and potassium were not significantly different (p>0.05) between both establishment periods. Leaf area, leaf mass, and nutrient (N, P, K, Ca, Mg) concentration of green leaves were also not significantly different (p>0.05) between both establishment periods. The results indicate that soil bulk density in chestnut orchards is dependent on the establishment periods, while soil chemical property and leaf nutrient concentration may be little influenced by the establishment periods.

• The Korean Journal of Community Living Science
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• v.15 no.3
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• pp.57-61
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• 2004

Many studies have presented results about the antioxidative and antimicrobial activities of Dandelions (Taraxacum officinale). There has yet to be a study which makes comparisons of nutrients based on the parts of the Dandelion. To identify the nutrient composition by part of dandelion, nutrient contents were analyzed. Dandelions were taken from Songpa-gu in Seoul and the nutrient composition of the flower, leaf and root were measured. The nutrient content of each part was analysed by using the method developed by the Association of Official Analytical Chemists (AOAC). The proximate components(moisture, protein, fat, fiber, ash, and carbohydrates), minerals and vitamins of the dandelion were analysed. The nutrient composition of the dandelions showed many significant differences among the parts when the differences were determined by using Duncan's multiple range test. The leaf contains more protein, ash, Ca, K, Mg, Zn, vitamin A, B$_1$, B$_2$, and C than the other parts. The root has much more fiber, carbohydrate, P and Fe content. The results demonstrate that dandelions could be used as a food source supplement for fiber, Ca, Fe and vitamin B$_2$ which are common nutritional deficiencies in Korea. It is recommended that more research for other bio-functional factors besides nutrients composition is needed to enhance the utilization of the dandelion.

• Korean Journal of Environmental Agriculture
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• v.30 no.2
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• pp.125-131
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• 2011

BACKGROUND: Reuse of waste nutrient solution for the cultivation of crops could lead to considerable conservation of water resources, plant nutrients, and water quality. Therefore, this study was conducted to evaluate the potential for reducing the use of chemical fertilizer in Chinese cabbage cultivation via the reuse of waste nutrient solution as an alternative irrigation resource. METHODS AND RESULTS: The nutrients supplied in the waste nutrient solution consisted of 1474.5, 1285.1, 991.6, and 872.6 mg/L for $K+$, ${NO_3}^-$, $Ca^{2+}$ and ${SO_4}^{2-}$, respectively. At 56 days after transplanting (DAT), the leaf length of Chinese cabbage plants irrigated with the waste nutrient solution treatment was significantly higher than that of plants irrigated using a conventional groundwater treatment. Additionally, the leaf width, fresh weight and dry weight of the plants irrigated with the waste nutrient solution were similar or greater than that of plants irrigated with a conventional treatment. Furthermore, the growth of plants treated with the waste nutrient solution +25% fertilizer was the highest among all tested treatments. CONCLUSION(s): These results indicate that the waste nutrient solution can be used as an alternate water resource for crop cultivation. In addition, it can contribute to reduce the fertilizer and to obtain the higher crop yield of Chinese cabbage.

• Journal of Bio-Environment Control
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• v.14 no.4
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• pp.289-297
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• 2005

This study was conducted to develop the suitable nutrient solutions for variable Cruciferae leafy vegetables. l/2, 1 and 3/2 strength of nutrient solution recommended by National Horticultural Research Institute were supplied to plants in deep flow technique systems during 25 days. The growth of pak-choi and leaf mustard 'Asia curled' was highest in the 3/2 strength, and kaie 'TBC' in the 1 strength. Mean cation ratio of nutrient solution for pak-choi, leaf mustard and kale was K $49.5\%$, Ca $35.8\%$ and Mg $14.7\%$, which was obtained by calculating the uptake rates of water and nutrients. Suitable composition of the nutrient solution for Cruciferae leafy vegetables was N 14, P 3, K 6.8, Ca 4.8, $Mg 2m{\cdot}L^{-1}$. To examine the suitability of nutrient solution developed for Cruciferae vegetables (NSC), plants were grown 4 times from Sep. 2003 to Oct. 2004. When plants were grown in NSC, relative growth rate increased 1.1 to 2.5 times and vitamin C content 1.06 to 1.52 times. The proper plants to apply NSC for functional leaf vegetable production were leaf mustard 'Asia recurled', 'Redcurled' and 'Pamagreen', kale 'TBC', 'Portugal' and 'Hanchu collard', leaf broccoli 'New green', pak-choi, baby cabbage 'Red king' and 'Green king', flowering red chinese cabbage and Korean cabbage.

• 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.16 no.4
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• pp.348-351
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• 2007

This study was conducted to find out the change of infernal quality, such as vitamin C and nitrate contents in some leaf vegetables grown hydropoincally in different nutrient conditions. Pak-choi (Brassica camperistis L. spp. chinesis Jusl.), chungchima (Lactuca sativa L. var. crispa cv. Chungchima) and romaine (Lactuca sativa L. var. longifolia Lam.) lettuces were cultivated for 2 weeks in 4 different nutrient solutions, such as tap water; no-nutrient, added $NH_4$, discarded $NO_3$, and supplied Yamazaki' solution for lettuce as a control. The growth of leaf vegetables was not different among nutrient solution treatments except tap water. The nitrate content showed the highest in control, and followed by $+NH_4$ treatment, $-NO_3$ and tap water treatment, regardless of kind of vegetables. The vitamin C content in 3 different vegetables showed the opposite result against nitrate content so that the treatment that showing the highest vitamin C content was tap water in romaine and chungchima lettuces, and $-NO_3$ treatment in pak-choi. The vitamin C and the nitrate content showed high correlations; $r=-0.614^*$ in pak-choi, $-0.651^*$ in romaine lettuce, and $-0.804^{**}$ in chungchima lettuce.