• Korean Journal of Environmental Agriculture
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• v.18 no.4
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• pp.304-309
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• 1999

Biomass, tissue (foliage, stem. and root) nutrient concentration, and nutrient use efficiency (NUE) were determined for 1-year-old Pinus densiflora, Larix leptolepis and Betula platyphvlla var. japonica seedlings in a greenhouse under nitrogen (N) and phosphorus (P) fertilization treatments. There were no consistent patterns in the effect of fertilization on seedling growth, however, in most cases the addition of N and P had no stimulating effect on biomass. In general, seedling tissue N and P concentrations increased after fertilization. It appeared that fertilization induced luxury nutrient consumption because uptake was increased without altering biomass. The NUE. calculated as the ratio between total above and belowground production and nutrient content in seedlings, decreased with increasing N and P supply for P. densiflora and B. platyphylla var. japonica while that for L. leptolepisthe did not change. B. platyphylla var. japonica had the highest NUE, L. leptolepis the lowest, with P. densiflora having the intermediate NUE.

• Journal of Crop Science and Biotechnology
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• v.10 no.2
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• pp.57-63
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• 2007

Due to the strong influence of nitrogen(N) on plant productivity, a vast amount of N fertilizers is used to maximize crop yield. Over-use of N fertilizers leads to severe pollution of the environment, especially the aquatic ecosystem, as well as reducing farmer's income. Growing of N-efficient cultivars is an important prerequisite for integrated nutrient management strategies in both low- and high-input agriculture. Taking maize as a sample crop, this paper reviews the response of plants to low N stress, the physiological processes which may control N-use efficiency in low-N input conditions, and the genetic and molecular biological aspects of N-use efficiency. Since the harvest index(HI) of modern cultivars is quite high, further improvement of these cultivars to adapt to low N soils should aim to increase their capacity to accumulate N at low N levels. To achieve this goal, establishment and maintenance of a large root system during the growth period may be essential. To reduce the cost of N and carbon for root growth, a strong response of lateral root growth to nitrate-rich patches may be desired. Furthermore, a large proportion of N accumulated in roots at early growth stages should be remobilized for grain growth in the late filling stage to increase N-utilization efficiency. Some QTLs and genes related to maize yield as well as root traits have been identified. However, their significance in improving maize NUE at low N inputs in the field need to be elucidated.

• Journal of Korean Society on Water Environment
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• v.22 no.4
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• pp.639-647
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• 2006

The temperature effect at $20^{\circ}$ and $10^{\circ}$ on the nutrient removal efficiency was evaluated in the combined biological nutrient removal system (CBNR) with anaerobic-intermittent aerobic-oxic reactors. The test was conducted under the conditions of various ratios of intermittent aeration time and distribution of influent raw water to CBNR. The removal efficiencies of organics, nitrogen and phosphorus were a little bit better at $20^{\circ}$ than at $10^{\circ}$. However the large difference of temperature effect on the nutrient removal efficiency between $20^{\circ}$ and $10^{\circ}$ was not appeared because of highly sustained MLSS concentrations in the reactors and controlled intermittent aeration time. In the removal of phosphorus, Mode III (50/70 min in aeration on/off time, 3 times of intermittent aeration) showed more effective compared with short aeration time of Mode IV. In case of N, P removal, the denitrification rate was lower in Mode A with splitted inflow into anaerobic and intermittent aeration basins than in Mode B with sole inflow into anaerobic basin.

• Journal of Environmental Health Sciences
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• v.28 no.1
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• pp.93-97
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• 2002

The aim of this study was to evaluate on the removal effect of total nitrogen and phosphorus with municipal wastewater in ultrasonic nutrient removal (UNR) process using ultrasonic sludge carbon source. The removal efficiency for total nitrogen was 44.2% at biological nutrient removal (BNR) process, 50.8% at UNR process. The removal efficiency for total phosphorus was 45.6% at BNR process, 46.2% at UNR process. The removal of nitrogen was effectively influenced by ultrasonic sludge carbon source.

• Journal of the East Asian Society of Dietary Life
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• v.9 no.3
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• pp.325-335
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• 1999

The aim of the present study was to evaluate the relations among nutrient intake. self body image and satisfaction, and physical fitness of college students in Taegu. A total of 213 apparently healthy college students living in Taegu were selected for the study. The following anthropometric measurements were made on all participants : weight, height: waist and hip circumferences, and bioimpedence. Using weight and height, the body mass index (kg/$m^2$) was calculated. The 24-hour recall were obtained from subjects. Dietary habits and energy expenditure were examined through questionnaires. Nutrients intake were analyzed by computer aided nutritional analysis program. Variables of Physical fitness were consisted of body fat, muscular strength and endurance, agility. power, flexibility, cardiorespiratory function, physical efficiency index(PEI). Data were analyzed by computer using the SAS 6.12(Statistical Analysis System). The mean heights and weights of these students were similar to those reported for the 50th percentile in a national survey. Nutrient intake of the college students in Taegu was considerably lower than RDA. The male subjects' mean intake of two nutrients, vitamin B$_2$ and calcium, were less than 55% of the RDAs. the female subjects' mean intake of two nutrients, iron and calcium, were less than 55% of the RDAs. A most variables of physical fitness except sit and reach in male students showed a significant higher values than those of female students. There was a significant positive relationship between PEI and the intake of animal protein, fat, Ca. and B$_2$ in male students. Also there was a significant positive relationship between exercise duration of PWC 170 and protein, fat, iron, vitamin A, B$_2$, niacin, and energy intake in female students. The muscular strength showed the significant correlation with weight, height, and waist circumference in male and female students. The cardiorespiratory function and Physical efficiency index showed significantly negative correlation with tricep and subscapular skin thickness in the female students. There were significantly positive correlations between WHR and body efficiency index in male students, and significantly positive correlations between WHR and the cardiorespiratory function in female students. There was no significant level of correlation between the degree of satisfaction of body image and physical efficiency index. However. there was a significant positive correlation between waist circumference (and weight) and physical efficiency index in male and female students and almost all of the surveyed male and female college students wanted less waist circumference or weight even though they were in the criteria of standard waist circumference or weight. In conclusion, a beneficial effect of adequate nutrient intake on physical fitness was found, college students must increase their energy and nutrient intake if it is below than the RDA for improving their physical fitness.

• Journal of Bio-Environment Control
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• v.21 no.2
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• pp.108-113
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• 2012

This study was conducted to evaluate soil nutrient concentrations and fertilizer recovery of sorghum- sudangrass hybrid (Sorghum bicolor (L.) Moench) as affected by organic nutrient sources. The treatments included livestock compost, alfalfa hay, oilcake, and chemical fertilizer. Nutrient applications were made at the rates equivalent to approximately 210 kg N per hectare. The oilcake and alfalfa materials had the lowest C : N ratio, but the livestock compost had the highest C:N ratio such as 33.7 : 1. The livestock compost resulted in the highest input to ground surface, which increased nutrient concentrations in soil. The oilcake and alfalfa materials with low C : N ratios increased N-mineralization rate in soil compared to livestock. The N uptake efficiency in plants treated by alfalfa or oilcake was approximately 60% of those treated with chemical fertilizer; but those with livestock compost had N uptake efficiency lower than 20%. The $P_2O_5$ uptake efficiency was the highest in the plants treated with the alfalfa hay, but the lowest in those with livestock compost. Recommendation of organic material selection should consider C:N ratio of the raw materials based on the individual crop requirement.

• Asian-Australasian Journal of Animal Sciences
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• v.33 no.9
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• pp.1520-1532
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• 2020

Objective: Due to rapid economic return, mixed crop-swine farming systems in Korea have become more intensive. Intensive farming practices often cause nutrient surpluses and lead to environmental pollution. Nutrient budgets can be used to evaluate the environmental impact and as a regulatory policy instrument for nutrient management. This study was conducted to select a nutrient budgeting approach applicable to the mixed crop-swine farms in Korea and suggest an effective manure treatment method to reduce on-farm nutrient production. Methods: In this study, we compared current and ideal gross nutrient balance (GNB) approaches of Organisation for Economic Co-operation and Development and soil system budget (SSB) approach with reference to on-farm manure treatment processes. Data obtained from farm census and published literature were used to develop the farm nutrient budgets. Results: The average nitrogen (N) and phosphorus (P) surpluses were approximately 11 times and over 7 times respectively higher in the GNB approaches than the SSB. After solid-liquid separation of manure, during liquid composting a change in aeration method from intermittent to continuous reduced the N and P loading about 50% and 47%, respectively. Although changing in solid composting method from turning only to turning+aeration improved the N removal efficiency by 30.5%, not much improvement in P removal efficiency was observed. Conclusion: Although the GNB approaches depict the impact of nutrients produced in the mixed crop-swine farms on the overall agricultural environment, the SSB approach shows the partitioning among different nutrient loss pathways and storage of nutrients within the soil system; thus, can help design sustainable nutrient management plans for the mixed cropswine farms. The study also suggests that continuous aeration for liquid composting and turning+aeration for solid composting can reduce nutrient loading to the soil.

• Journal of Korean Society of Forest Science
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• v.88 no.2
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• pp.266-272
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• 1999

Aboveground biomass and nutrient contents of a 31-year-old pitch pine(Pinus rigida) and a 31-year-old Japanese larch(Larix leptolepis) plantations were measured in the Chungbu Forest Experiment Station, Kyunggi Province. Aboveground biomass was 170.2ton/ha in the pitch pine and 87.2ton/ha in the Japanese larch plantations. Aboveground biomass difference between both plantations was due to the difference of stand density. Aboveground biomass in both plantations was allocated as follows : stemwood>branch>stembark>needle. The concentrations of all nutrients(N, P, K, Ca, Mg) were generally higher in the Japanese larch needle than in the pitch pine because of high nutrient uptake characteristics of larch compared with pine tree species. The nutrient concentration in different tree tissues in both tree species decreased in the order of needle>branch>stembark>stemwood. Nutrient contents of aboveground biomass were : N, 335.9 ; P, 40.4 ; K, 121.4 ; Ca, 188.6 ; Mg, 93.8kg/ha in the pitch pine plantation, while nutrient contents in the Japanese larch plantation were : N, 226 ; P, 11.5 ; K, 72.9 ; Ca, 75.7 ; Mg, 37.1kg/ha. The nitrogen use efficiency calculated as the biomass produced by one unit of nitrogen was higher in the pitch pine than in the Japanese larch plantations. This result suggests that pine with high nitrogen use efficiency could be adapted in lower site productivity area compared with larch tree species.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.55 no.3
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• pp.268-274
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• 2010

The aim of our study was to investigate the interactive effects of container size and nutrient supply on plant growth, chlorophyll synthesis, transpiration, $CO_2$ assimilation, water use efficiency (WUE), and nutrient uptake of vinca plant (Catharanthus roseus). A complete experiment utilizing four concentrations of fertilizer and three volumes of containers was conducted. As the container size was increased, the plant height, leaf area, and dry weight of vinca significantly increased regardless of fertilizer level. The leaf area and dry weight of vinca were highly sensitive to the container size. However, the chlorophyll contents of vinca 20 days after the transplant significantly increased with decreasing container sizes and increasing fertilizer concentrations. Significant differences in transpiration and $CO_2$ assimilation occurred with the use of differentfertilizer solutions, but the highest values for transpiration and $CO_2$ assimilation were in plants grown in the 15 cm-diameter containers. The highest water use efficiency was observed in the plants grown in 10 cm-containers with 4 dS/m of fertilizer, and there were no significant differences in WUE values among container sizes with fertilizer concentrations of 0, 1, or 2 dS/m. No significant difference in nutrient uptake was observed among the fertilizer levels or among the container sizes. However, at a fertilizer concentration of 4 dS/m, the uptake of several nutrients, including N, P, K, Ca, Mg, B and Fe, was higher in small containers than in larger ones.

• Journal of Korean Society on Water Environment
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• v.28 no.5
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• pp.663-668
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• 2012

The feasibility of enhancing biological nutrient removal from an industrial wastewater was tested with food waste leachate and sugar liquid waste as external carbon sources. Long term influences of adding external carbon sources were investigated to see how the biological nutrient removal process worked in terms of the removal efficiency. The addition of the external carbons led to a significant improvement in the removal efficiency of nutrients: from 49% to approximately 76% for nitrogen and from 64% to around 80% for phosphorus. Approximately, 20% of the removal nitrogen was synthesized into biomass, while the remaining 80% was denitrified. Though the addition of external carbon sources improved nutrient removal, it also increased the waste sludge production substantially. The optimal observed BOD/TN ratio, based on nitrogen removal and sludge production, was around 4.0 in this study.