• Journal of Wetlands Research
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• v.12 no.1
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• pp.1-14
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• 2010

Changes in wetland soil properties of two constructed wetlands after their constructions were compared to those of a natural wetland to determine if they could be used for the evaluation of the success of constructed wetlands and the assessment of their functions. One natural wetland as a reference wetland and two constructed wetlands(treatment wetland and experimental wetland) with different contaminant inflow characteristics were selected for this study. Major physicochemical properties of wetland soil such as soil texture, water content, pH, CEC(cation exchange capacity), organic matter content, total nitrogen, and available phosphorus were monitored to investigate the effects of inundation and accumulation of organic matters and nutrients on the wetland soil development. There was a clear difference in soil texture between the natural wetland and the constructed ones, with the high sand content in the constructed wetlands as compared to the high clay content in the natural one. Gradual increases of silt and clay contents over time were observed in the constructed wetlands. The soil of the natural wetland was higher in water content and organic matter but lower in pH than those of the constructed wetlands. The pH of the constructed wetlands reached near neutral ranges after initial increase. CEC and nutrient concentrations of the constructed wetlands seemed to be affected mainly by outside inflows of organic matter and contaminants. Concentrations of organic matter and nutrients decreased over time in the experimental wetland where surface and deep soils with different characteristics were mixed during its construction, suggesting that changes in soil properties during wetland constructions may affect the development of wetland soils or wetland biogeochemistry. This study showed that changes in physicochemical properties of soils in constructed wetlands could be used to assess the success of constructed wetlands and their functions, and also the importance of reference wetlands for the appropriate assessment.

• Korean Journal of Ecology and Environment
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• v.37 no.3 s.108
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• pp.332-343
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• 2004

This study was conducted to test a possibility of water quality improvement using a filter-feeding bivalve (Corbicula leana). In mesocosm scale (width ${\times}$ length ${\times}$ depth: 3 m ${\times}$ 3 m ${\times}$ 0.5 m), we investigated the changes of dissolved nutrient and particulate matter including both abiotic and biotic seston. Short term (16 days) mesocosm experiment was conducted in two stages: the first stage for 8 days and consecutive 8 days of the second stage. Both treatment and control mesocosm were switched over by translocating mussels from the treatment mesocosm to the control, at 8th days since the start of the experiment. This design made it possible to compare mussel effect on the water quality change more clearly. The high mortality of mussel was observed in the treatment of the first stage, but it decreased rapidly and stabilized on the 8th day to less than< 4 ind $day^{-1}$. Chl. a concentration in the treatment mesocosm of the first and second stage decreased to 71 and 88% of initial concentration, respectively, and suspended solids decreased to 70 and 77%. At those times, average filtering rate were 0.46 and 0.61 mL AFDW $mg^{-1}$ $hr^{-1}$, respectively. Both $NH_3-N$ and dissolved total phosphorus (DTP) concentrations increased with the mussel mortality. $NH_3-N$ concentration was positively correlated with the mussel mortality, while DTP concentration showed negative correlation with it. After translocating mussel from the treatment to the control, $NH_3-N$ concentration significantly increased compared with that of initial control. Although DTP concentration also increased, there was no significant difference relative to that of initial control. These results suggest that application of this filter-feeding bivalve in a eutrophic reservoir could be a potential tool to improve water quality if mussels could acclimatize successfully in early stage of the introduction.

• Korean Journal of Ecology and Environment
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• v.49 no.4
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• pp.354-374
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• 2016

This study explored spatiotemporal variability of water quality in correspondence with hydrometeorological factors in the five stations of Paldang Reservoir located in the Han River during 4 years from May 2012 to December 2015. Variability of basic water quality factors were largely related with seasonal fluctuations of hydrology. Temperature stratification occurred in the deep dam station, and prolonged hypoxia was observed during the draught year. Nitrogen nutrients were increased with decreasing inflow in which changing pattern of $NH_4$ reversed to $NO_3$ by the effect of treated wastewater effluent. Phosphorus increase was manifest during the period of high inflow or severe drought. Chl-a variation was reversely related with both flow change and AGP(algal growth potential) variations. Our study demonstrated that water quality variability in Paldang Reservoir was largely attributed to both natural and operational changes of inflow and outflow (including water intake) based on major pollution source of the treated wastewater (total amount of $472{\times}10^3m^3d^{-1}$) entering to the water system from watershed. In the process of water quality variability, meteorological (e.g., flood, typhoon, abnormal rainfall, scorching heat of summer) and hydrological factors (inflow and discharge) were likely to work dynamically with nutrients pulse, dilution, absorption, concentration and sedimentation. We underline comprehensive limnological study related to hydro-meteorolology to understand short- and long-term water quality variability in river-type large reservoir and suggest the necessity of P-free wastewater treatment for the effective measure of reducing pollution level of Paldang drinking water resource.

• Journal of The Korean Society of Grassland and Forage Science
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• v.5 no.3
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• pp.187-194
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• 1985

This field experiment was carried out to determine the effects of thirteen different fertilizer levels of nitrogen(N), phosphorus($P_2O_5$) and potassium($K_2O$) on the content of crude protein, crude fiber, mineral constituents of product and tree growth forest pasture with 40-50% shading. The experiment was arranged as a randomized block design and performed in the suburban forest of Suweon in 1984. The results obtained are summarized as follows: 1. Crude protein content and total protein yield were higher in the plot of 28 and 42kg $N/_{10a}$, regardless of $P_2O_5\;and\;K_2O$ level, while those were the lowest in zero fertilizer and N-zero fertilizer plots. 2. The contents of lignin and silica were significantly low in the high N fertilizer level, and the contents of NDF, ADF, cellulose and hemicellulose were not affected by different fertilizer levels. However, the content of crude fiber tended to be low with high N, regardless of $P_2O_5\;and\;K_2O$. 3. The contents of N,K and $SiO_2$ of grasses were influenced by different fertilizer levels. However, those of P,Ca,Ma and Na showed little differences. 4. The recovery percentage of NPK was higher in the plot of standard fertilizer level with 28-20-24 kg/10a, and higher recovery percentage was observed in $K_2O$, followed by N and $P_2O_5$ in that order. 5. The growth of tree was increased as the level of N fertilizer was increased, but no such trend was noted by $P_2O_5\;and\;K_2O$ levels. 6. Crude protein, crude fiber, some mineral contituents of grasses, and growth of tree were influenced by N level, regardless of $P_2O_5\;and\;K_2O$. And the optimum fertilizer level of $N-P_2O_5-K_2O$ seemed to be 28-20-24 kg/10a for the production of grasses with higher quality and more yield in the forest.

• The Korean Journal of Food And Nutrition
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• v.28 no.2
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• pp.302-312
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• 2015

This study was conducted to evaluate the effects of constitutional diets in comparison with general low calorie diets in obese women. The subjects were 52 adult obese women that participated in a calorie restriction diet program (control group, n=16) or a constitutional diet program (experimental group, n=36) for 8 weeks. The subjects in the experimental group were classified as negative (Yin) or positive (Yang) constitution. The obesity management program focused on the calorie restriction diet (300~400 kcal reduction per day) for the control group, whereas, for a constitutional diet without calorie restrictions was allowed for the experimental group. Daily intakes of nutrient and food were assessed using a 24 hr recall method. Body measurements and blood biochemical parameters were measured at baseline and after 8 weeks. After the intervention, weight, body fat, BMI, waist circumference and hip circumference decreased significantly in both the control and experimental group. Energy intake increased from 1,679.6 kcal to 1,810.6 kcal along with significant increase in protein, carbohydrate, fiber, calcium, phosphorus, iron, zinc, vitamin A, vitamin $B_1$, vitamin $B_2$, niacin and vitamin C in the experimental group. Calcium intake increased from 54.0% to 72.4% of DRI in the experimental group. Hemoglobin concentrations were significantly decreased in the control group, but were increased in the experimental group. In addition, blood glucose, serum total cholesterol and triglyceride were significantly decreased in the experimental group. In conclusion, consumption of a constitutional diet without calorie restrictions for 8 weeks was effective for weight reduction with improvement of blood glucose, serum cholesterol and triglyceride.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.5
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• pp.986-992
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• 2001

To assess the food intake and diet quality of middle school students who live in Kangneung area, a dietary survey using 3-day food record was conducted with 226 subjects. Seventy five percent of total food intake was in the form of plant foods and the rest in the form of animal food. Diet qualify was assessed by food group pattern, dietary diversity score (DDS), and dietary variety score (DVS). When counting the major food groups consumed, 53% of subjects had a DDS of 3 and 35% of subjects had a DDS of 4. When investigating the consumption pattern of the major five food groups, only 10.2% of subjects consumed foods from all five groups. The groups most frequently missed were dairy products (73.0%) and fruits (71.7%). On average, subjects habitually consumed 22.6 different foods daily, with the mean score of diet variety for males (22.1) being significantly lower than for females (22.9). Correlation coefficients between nutrient adequacy ratio (NAR) and DVS ranged from r=0.40 for vitamin B$_1$to r=0.61 for phosphorus. NAR also improved as the number of foods or food groups consumed increased (p<0.001). Associations between the NAR and high level of DVS was more positive than those between the NAR with DDS. When assessing the dietary quality of subjects using DDS and DVS, many people appeared not to have a desirable food intake. Therefore, to lead them to have nutritionally balanced diet, educating students and their parents on nutrients and suggesting guidelines for a desirable diet is considered to be essential so that they can intake from all of major food groups and have various foods in their diet.

• FLOWER RESEARCH JOURNAL
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• v.18 no.4
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• pp.238-243
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• 2010

This study was conducted to investigate effects of nutrient solution pH control agent and foliar spray of ethephon on the reduction of stem inside-cavity and improvement of flower quality in chrysanthemum 'Baekma'. Changes of pH in nutrient solution as affected by the kind of pH control agent showed more settled pattern in the plot of KOH treatment than in others. Plant growth and development such as cut flower length, leaf numbers, cut flower weight and petal number were the greatest in the plot of KOH. However, the size and area of stem cavity was large in KOH rather than $KHCO_3$. As changes in the absorbing patterns of mineral elements as affected by nutrient solution pH control agent in closed system, contents of total nitrate, phosphorus, potassium and calcium by $KHCO_3$ was absorbed into the plant less than KOH, so that it remained a lot of mineral element residues rather than KOH in closed system. Plant growth as affected by the foliar spray of ethephon showed growth retardation effect in the plot of solution diluted to 1 : 500 and growth promotion effect in the plot of solution diluted to 1 : 1,000 or 1 : 2,000. The number of petals was the best in the plot of foliar spray of ethephon solution diluted to 1 : 1,000 before flowering at 45 days showing 331 petals compared to control showing 302 petals. The size and area of stem cavity as affected the foliar spray of ethephon was smaller 1 mm and 7%, respectively, in the plot of solution diluted to 1 : 2,000 before flowering at 30 days than in control. Therefore, treating pH stabilization using KOH after floral initiation stage with the foliar spray of ethephon solution diluted to 1 : 2,000 before flowering at 30 days would help to reduce stem cavity size and improve flower quality in hydroponically grown chrysanthemum 'Baekma'.

• Korean Journal of Soil Science and Fertilizer
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• v.22 no.1
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• pp.45-52
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• 1989

The effects of soil properties and N, P and K application rates on the contents of inorganic constituents in the rhizomas of Ji-whang were investigated to know the condition for producing the better quality rhizoma of Ji-whang. Most of soil texture for Ji-whang cultivating belongs to sandy clay loam and sandy loam soils. The nitrogen contents in the rhizomas of Ji-whang was negatively correlated with the contents of organic matter and total nitrogen in surface soils, whereas positively correlated with the sand contents in subsoils. The calcium contents in the rhizomas of Ji-whang were negatively correlated with the sand contents, however, positively correlated with the contents of clay and organic matter in soils. The iron contents was positively correlated with the contents of clay, available phosphorus and exchangeable potassium in surface soils. Much more contents of the inorganic constituents in the leaf of Ji-whang was generally detected than that in the rhizoma of Ji-whang. The contents of iron and copper in the leaf was determined to be more than that in the rhizomas by ten times. In the results of field experiments, it is apparent that the nitrogen contents in the rhizoma and leaf increased with increasing N application rate more than 20kg/10a and 10kg/10a, respectively.

• Korean Journal of Soil Science and Fertilizer
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• v.40 no.1
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• pp.85-94
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• 2007

To determine the influence of food waste compost (FWC) application on paddy soil, FWC was applied to the paddy soil and then compared with farmer's practice as to the effects on rice and soil environment. Initially, pig manure compost (PMC) had high content of phosphorus ($15g\;kg^{-1}$) and potassium ($23g\;kg^{-1}$), while FWC had high content of total nitrogen ($13g\;kg^{-1}$) and salinity ($18.5g\;kg^{-1}$). Comparison was also made between chemical fertilizer and FWC use as a trial in the paddy field under the clay loam and sandy loam soil. In the panicle formation stage, chemical fertilizer application was proper in clay loam while PMC application was proper in sandy loam. However, chemical fertilizer produced higher yield compared to compost treatment, both on clay loam and sandy loam with 20~25% and 17~19%, respectively. The lower yield in sandy loam maybe due to slow mineralization of compost such that the crop did not effectively use it. Organic matter content in paddy soil after experiment was higher in FWC and PMC plots compared to that in chemical fertilizer plots. But the other soil properties were comparable. Therefore, the FWC compost had little effect on soil when it use as a trial in paddy field. Likewise, after the application of FWC as a trial, analysis of nitrate nitrogen and ammonium nitrogen in the surface water and 60 cm depth of paddy soil water nine days after planting was done. Results revealed that concentration of ammonium nitrogen was similar to irrigation water while nitrate nitrogen concentration was not detected, and hence did not contribute to water pollution. It is concluded that the application of FWC in the paddy field had not affected on environmental pollution in the paddy field. But its use as compost during rice culture reduced yield quantity. Such study should include selection of compost material, amount and method of compost application.

• Journal of Wetlands Research
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• v.23 no.4
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• pp.352-363
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• 2021

The purpose of this study was to evaluate the load of nutrients contained in the drainage discharged from the facility horticultural complex and to use them for re-use of fluids and design for introduction of water treatment plants. Representative hydroponic cultivation crops were selected as tomato, paprika, cucumber, and strawberry, and the total number of samples analyzed for water quality was 80. As a result of the analysis, since various fertilizer components such as N, P, K⁺, Na⁺, Mg²⁺, Ca²⁺, Si₄⁺, HCO₃^-, Cl^-, S^2-, Fe, Mn, Cu, Zn, Mo and B are contained at very high concentrations in the drainage, the need for water treatment was confirmed. Through statistical analysis, it was analyzed that the drainage concentration of strawberries was lower than that of tomatoes, paprika, and cucumbers. In the case of tomatoes, these essential ion concentrations are the highest, so it was confirmed that they are subject to valuable resources in terms of reuse of fertilizers. The load of N and P of the drainage discharged from the facility horticultural complex 1m² was analyzed. For N, the daily processing capacity of 4.0 kg of tomatoes, 3.3 kg of paprika, 3.0 kg of cucumbers, and 1.5 kg of strawberries was calculated based on 1 ha. It was suggested that the P concentration needs a scale and capacity that can handle 0.5 kg of tomatoes, 0.6 kg of paprika, 0.4 kg of cucumber, and 0.2 kg of strawberries per day. Through this study, the amount of nitrogen and phosphorus contained in the drainage discharged from the greenhouse of each crop was evaluated to analyze the economy. In addition, it was expected to be used as basic data that can be used to calculate the treatment capacity to be reflected when introducing water treatment facilities in facility horticultural complexes for sustainable agriculture.