• Journal of the Korean Dietetic Association
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• v.18 no.2
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• pp.170-185
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• 2012

The purpose of this study was to explore nutrition teachers/dietitians' perception towards production management practices as well as the importance & performance of nutrient preservation during production by school foodservices. A total of 120 school nutrition teachers/dietitians in the Daegu area participated in this study. The data were analyzed by descriptive analysis, t-test, and ANOVA using SPSS/Windows (ver 17.0). A questionnaire consisted of three dimensions with 66 items concerning the general characteristics of schools and respondents, production management practices, and perceived importance and performance of nutrient preservation. Exactly 79.2% of dietitians responded that scheduling of production management is necessary, and 52.5% of respondents perceived that their knowledge for nutrient preservation is of normal/average level. Thirty-eight percent of respondents did not establish scheduling of production management; according to them, cooking stage has priority over other stages of nutrient preservation. Perceived importance score was higher than perceived performance score in all stages of production management. The difference between perceived importance and performance in the production scheduling stage was found to be statistically significant. The results indicate that nutrition control point should be established and managed to prevent nutrient loss in all production stages. Further, dietitians who do not take measures to reduce nutrient loss should be carefully educated on the importance of nutrient control and be motivated to follow guidelines on nutrient preservation.

• Korean Journal of Community Nutrition
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• v.13 no.6
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• pp.879-889
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• 2008

The purpose of this study was to examine nutrition management conditions of lunch with the elementary schools and middle schools in the Changwon area. 292 students (5th and 6th graders) from three elementary schools and 330 students from three middle schools (boys, girls, and co-ed) participated in the aggregate selective plate waste measurement for 5 days. Planned menus, serving sizes and plate waste amount data were collected. Nutrient analyses for the planned, served and consumed menus at school lunches were performed by using CAN-PRO 3.0. Nutrient analyses of the planned, served and consumed menus were compared with nutrient management standard (former edition) for school lunch and 1/3 Korean Dietary Reference Intakes (KDRIs). Significant difference was found in the average consumption rate between the elementary schools (82.2%) and the middle schools (71.8%). Specifically, the consumption rates of steamed rice (p < 0.001), side dish 1 (p < 0.001), and Kimchi (p < 0.01) at the middle schools were significantly lower than those of the elementary schools. When the nutrient contents in the served menus were put into percentages to the nutrient contents in the planned menus, middle schools (92.3%) showed bigger serving loss than the elementary schools (95.4%). In the nutrient assessment comparied with nutrient management standard (former edition), middle school lunches showed comparatively less energy or less some nutrient contents against the standard than the elementary school lunches. Specifically, in case of boys in middle schools, Vitamin C was the only nutrient content that satisfied the standard in the planned menus, served menus and consumed menus. In the 1/3 KDRIs based assessment, middle schoolers were found not to be provided proper nutrients with school lunches. To improve nutrition management at middle school foodservices, dietitians should reinforce nutrient assessment for menu planning, and try to decrease serving loss and plate waste.

• Nutrition Research and Practice
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• v.11 no.6
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• pp.500-506
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• 2017

BACKGROUND/OBJECTIVES: Food composition databases are necessary for assessing dietary intakes. Developing and maintaining a high quality database is difficult because of the high cost of analyzing nutrient profiles and the recent fast-changing food marketplace. Thus, priorities have to be set for developing and updating the database. We aimed to identify key foods in the Korean diet to set priorities for future analysis of foods. SUBJECTS/METHODS: The food consumption data of the Korea National Health and Nutrition Examination Surveys 2013-2014 were used. We modified the US Department of Agriculture's key food approach. First, major foods were analyzed, contributing to 75%, 80%, 85%, or 90% of each nutrient intake. Second, the cumulative contributions to nutrient intakes were compared before and after excluding the foods least commonly consumed by individuals. Third, total nutrient score for each food was calculated by summing all percent contributions times 100 for nutrients. To set priorities among the foods in the list, we sorted the score in descending order and then compared total percent contributions of foods, within the 100, 90, 85, 80, and 75 percentiles of the list. Finally, we selected the minimum list of foods contributing to at least 90% of the key nutrient intake as key items for analysis. RESULTS: Among the 1,575 foods consumed by individuals, 456 were selected as key foods. Those foods were chosen as items above the 80 percentile of the total nutrient score, among the foods contributing at least 85% of any nutrient intake. On an average, the selected key foods contributed to more than 90% of key nutrient intake. CONCLUSIONS: In total, 456 foods, contributing at least 90% of the key nutrient intake, were selected as key foods. This approach to select a minimum list of key foods will be helpful for systematically updating and revising food composition databases.

• Korean Journal of Organic Agriculture
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• v.31 no.3
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• pp.167-189
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• 2023

Korea has become the highest nitrogen balance (228 kg/ha) among 34 OECD member countries, and has the stigma of being a 'Nutrient overload country' as of 2019. Accordingly, research on the derivation and utilization of nutrient balance indicators and the 'regional nutrient management system' are being promoted to improve Korea's nutrient balance. It is necessary to support these policies and studies, form a public consensus on improving the nutrient balance, and evaluate the function of the public benefit. This paper aims to estimate the public benefit value of improving the nutrient balance based on an analysis of consumers' willingness to pay and recognition of Korea's nutrient excess for 600 consumers nationwide. As results, 21.2% of the respondents said they were aware of excessive nutrients in Korea, and 76.7% of the respondents said they were aware of the need for nutrient management. The average amount of intention to pay for the improvement of three pollution (soil, water quality, and air) that can occur due to a nutrient overload was ￦2,321.1 for soil pollution improvement, ￦2,391.2 for water pollution improvement, and ￦2,377.9 for air pollution improvement. The average willingness to pay for the three pollution reduction was ￦6,002.3. These results are expected to be used to form a public consensus on the balance of payments and to establish measures to enhance public interest values in the future.

• Korean Journal of Soil Science and Fertilizer
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• v.36 no.4
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• pp.225-232
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• 2003

Nutrients and water absorption by Citrus unshiu Marc. cv. Miyagawa Wase were examined using spray type of out-door hydroponics system. Three different concentration levels of nutrient solution were treated to citrus trees to examine nutrient uptake. To do so, concentration and the volume change of nutrient solution was measured for each treatment. By weighing the volume of solution and citrus trees, amounts of water uptake and fresh weight increase were observed periodically. Water uptake by trees increased as tree grew and time elapsed, but was lower at high level of nutrient concentration than the rest, due partly to the reduction in hydraulic conductance and to the sustained high salt concentration. Rapid increase in fresh weight and nutrient uptake occurred from May to July and from August to September. The amounts of nutrient uptake were significantly different among nutrient levels: the higher concentration, the greater uptake by citrus tree. The absorbed amounts of $NO_3$, K and Ca were much higher than those of $NH_4$, S, P, Mg, and Fe. Most mineral contents in leaves were proportional to the concentration of supplied nutrient solutions. From the results of nutrient absorption and contents in leaves at different levels of nutrient solutions, the composition of major elements for citrus nutrient solution can be modified as follows: 27.1, 16.5, 66.0, 80.0, and $24.0mg\;L^{-1}$ for N, P, K, Ca, and Mg, respectively.

• Journal of Bio-Environment Control
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• v.17 no.4
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• pp.252-260
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• 2008

This study was conducted to observe the characteristics of mineral nutrient uptake of single-node cutting rose 'Versilla' and to determine optimal nutrient solution control method for soilless culture of 'Versilla' in a closed hydroponic system. Nutrient solution was managed by five different control methods: macro- and micro-element control in aeroponic system (M&M), macroelement control in aeroponic system (M), nutrient solution supplement in aeroponic system (S); electrical conductivity (EC) control in aeroponic system(EC-A); EC control in deep flow technique system(EC-D). The concentration of $NO_3$-N exceeds optimal range whereas P and Mg decreased at the later stage of plant growth with the EC control method, EC-A and EC-D. The overall mineral nutrient content increased with S. On the other hand the nutrient content at the root environment was maintained optimal with M&M and M. The nutrient solution control methods had significantly effect on the cut-flower quality. In the M&M and M, flower length, fresh weight and root activity were higher than those with the other mineral nutrients control methods. The maximal efficiency of photochemistry (Fv/Fm) was higher for M&M, M and S than that with EC-A and EC-D. Based on the above results, it is highly recommended to control nutrient solution by mineral nutrient control methods (M&M and M) in a closed hydroponic system for single-node cutting rose, 'Versillia'.

• 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.

• Asian-Australasian Journal of Animal Sciences
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• v.12 no.4
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• pp.667-674
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• 1999

Intensive livestock production has increased dramatically in Europe since the 1960s, particularly. in Northern and Central European countries, resulting in large increases in the nutrient pollution of surface and ground waters and in atmospheric emissions of ammonia. This has arisen due to inadequate management of the large amounts manure produced, particularly where there has been insufficient land area used for efficient nutrient reuse in crop production. Nutrient pollution from intensive livestock production has progressively degraded the quality of water resources in many parts of Europe, with eutrophication of many inland and coastal waters, as well as soil acidification and ecosystem degradation. These problems have been known for many years, and although there are various international agreements on transboundary pollution, it is largely left to individual countries to set and enforce standards. Consequently, a number of different approaches are employed, although the common feature of these is to encourage farmers to use the nutrients in animal manures efficiently according to crop requirements, which also reduces the potential for accumulation in soil and subsequent loss to the environment. This paper reviews nutrient production and use in Europe and some of the strategies employed to avoid and reduce nutrient pollution.

• Journal of Bio-Environment Control
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• v.2 no.2
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• pp.99-109
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• 1993

Cooling of nutrient solution is essential to improve the growth environment of crops in hydroponic culture during summer season in Korea. This study was carried out to provide fundamental data for development of the cooling system satisfying the required cooling load of nutrient solution in hydroponic greenhouse. A numerical model for prediction of the cooling load of nutrient solution in hydroponic greenhouse was developed, and the results by the model showed good agreements with those by experiments. Main factors effecting on cooling load were solar radiation and air temperature in weather data, and conductivity of planting board and area ratio of bed to floor in greenhouse parameters. Using the model developed, the design cooling load of nutrient solution in hydroponic greenhouse of 1,000$m^2$(300pyong) was predicted to be 95,000 kJ/hr in Suwon and the vicinity.

• Journal of Biosystems Engineering
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• v.20 no.4
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• pp.383-389
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• 1995

This study was conducted to develop an automatic nutrient control system for trickle application of nutrient solution. Temperature, electric conductivity(EC). pH and dissolved oxygen(DO) were selected as control variables. A controller using single-chip microcomputer was constructed. An automatic control system for nutrient solution and a controller using single-chip microcomputer with control algorithm were developed. The control system was tested, and could control temperature, EC and pH within the error ranges of $pm 0.2^{circ} pm 0.2mS/cm, pm 0.1pH$, respectively.