• Korean Journal of Soil Science and Fertilizer
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• v.6 no.2
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• pp.95-105
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• 1973

Sink (grain)-filling rates of IR667 line (Suwon 213 and 214) and local leading varieties (Jinheung and Paldal) were investigated in relation to sink-source ratio, sink-source distance, forms of photosynthates, and weather factors. The results are as follows. 1. IR667 line have higher maximum filling rate (g. grain/day. ear) and shorter duration to reach maximum filling rate than local varieties. The curve pattern of sink-filling rate was high and steep type in IR667 line and low and broad type in local varieties. 2. Weather factors seem to give little effect on the curve pattern of sink-filling rate. 3. The functional sink-source distance (actual sink-source distance multiplied by the contribution rate of leaf for grain production) was shorter in upper leaves (flag and 2nd leaf) for IR667 line, the upper leaf-dependent type in grain production, and was longer in lower leaves (3rd and 4th) for local varieties, the lower leaf-dependent type. Specially short first internode from top may contribute to the upper leaf depencency of IR667 line. 4. According to free sugar-starch ratio (sugar/starch) in the culm and leaf sheath IR667 line could be classified as the high sugar type and the local varieties as the high starch type. The ratio of transportable form (sugar) to non transportable photosynthate (starch) seems to relate with sink-filling rate. And high sugar type is expected to have higher efficiency for grain production in view of energy balance. 5. A hypothesis that the higher in the uniformity within the series of productive structure the more efficient in grain production is proposed and discussed in relation to productivity. 6. According to the pattern of percent nutrient retention of each leaf blade IR667 showed the central retention type and Jinheung showed the apical retention type and each retention type appears to be a cause of each canopy conservation pattern. 7. From the content and percent distribution of nutrient in various organ IR667 could be classified as the leaf sheath dominant type and Jinheung as the leaf blade dominant type. 8. The fact that the greater the percent translocation of nutrient into grain the greater the percent nutrient retention in leaf blade was held between nitrogen and phosphorus within a variety and between varieties within a nutrient (N, P or K).

• Proceedings of the Korean Aquaculture Society Conference
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• 2003.10a
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• pp.17-18
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• 2003

Although flounder is one of the most important marine fish for aquaculture in Korea, feeding the flounder in commercial farms depends mainly on moist pellet in which over 70% frozen fishes (e.g. frozen horse mackerel) are incorporated in its formulation. Therefore, for further expansion of flounder farming, it is essential to employ practical formulated feeds that can support reasonable growth. Development of nutritionally balanced and cost-effective feeds is dependant on the information about nutritional requirement and feed utilization of the species. Nutrient and energy source in feed are needed for the growth and maintenance of fish. Protein is probably the most important nutrient affecting fish growth and feed cost. Therefore, it is essential to determine the optimum dietary protein level for the growth of fish, both its high proportion in the feed and because it is the main factor in determining feed cost. Dietary energy level is also critical because protein source in the feed is utilized as an energy source when the feed deficient in energy is fed to fish, whereas when the feed excess in energy is fed to fish, feed consumption decreased and resulted in growth reduction due to lack of other necessary nutrients for normal growth. Improper dietary protein, energy levels and/or their ratio will lead to an increase of fish production cost and deterioration of water quality resulting from wasted feed; thus, they are important in formulating commercial feed. Dietary lipids play important roles in providing energy and essential fatty acid for normal growth and survival of fish. Although carbohydrates are not essential nutrients for carnivorous fish, these compounds play important roles as a low-cost energy source for protein sparing and also as a feed binder. Nutrition researches for flounder have identified its requirements of protein, lipid and essential fatty acid, vitamin, and minerals for normal growth. Other studies have also been carried out to investigate the utilization of the protein, lipid and carbohydrate sources. Based on these nutritional information obtained, practical feed formulations have been studied for improve aquaculture production of flounder. The results of the researches on utilization of dietary protein, lipid and carbohydrate by flounder are discussed in this review.

• Magazine of the Korean Society of Agricultural Engineers
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• v.39 no.2
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• pp.53-61
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• 1997

The interface system, GIS-AGNPS was to be validated with field data from six tested small watersheds ranging from 0.7 to 4.7$km^2$ in size which have steep topography and complex landuses. The model validation involved the calibration of input parameters and component modifications, in efforts to develop a model applicable to general uses for identifying and controlling nonpoint source pollution loads from agricultural watersheds. The simulated direct runoff from AGNPS was in good agreement with the field data for the averaged antecedent moisture conditions or AMC- II. The results differed, however, from the observed for AMC- I or III. A simple empirical relationship was proposed to estimate the curve number for AMC- I or m from AMC- II, which was found to result in simulated runoff close to the observed. The peak runoff relationship at AGNPS was also modified to reflect the watershed conditions and tested satisfactorily with the field data. The simulated sediment yields from the watersheds were fair as compared to the observed. Nutrient loads simulated from the model were different from the observed data. It appeared that the model was incapable of adequate depicting nutrient transport processes at paddy field and other landuses of the tested watersheds. Some modifications may be needed for the accurate representing the processes at paddy field.

• Environmental Engineering Research
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• v.16 no.4
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• pp.213-218
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• 2011

The two-stage intermittent aeration activated sludge process (IAP) and dynamic-flow intermittent aeration activated sludge process (DFP) were investigated for the nutrient removal of domestic wastewater. Three sets of IAP and one set of DFP were operated. The fermented settled sludge taken from the primary settling tank was added to two IAP and one DFP as an external electron donor, with one IAP, in which an external carbon source was not added, as a control. All the systems were operated at a sludge retention time of 20 days and a hydraulic retention time of 12 hr. A Higher denitrification rate was observed with the fermented settled sludge for the denitrification compared to the process without the addition of the organic source. The result indicates that the fermented acid from the primary domestic sludge has been proved to be an excellent electron donor for denitrification and biological phosphorus removal with IAP and DFP in treating relatively low C/N ratio(Carbon / Nitrogen ratio) wastewater. Phosphate accumulating organisms have a capability of competing with denitrifiers in the presence of volatile organic acids under anoxic conditions.

• Korean Journal of Soil Science and Fertilizer
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• v.49 no.5
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• pp.440-448
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• 2016

Nonpoint sources of pollution (NPS) is defined as diffuse discharges of pollutants (e.g., nutrient, pesticide, sediment, and enteric microorganism) throughout the natural environment and they are associated with a variety of farming practices. Previous studies found that water soluble anionic polyacrylamide (PAM) is one of the highly effective measures for enhancing infiltration, reducing runoff, preventing erosion, controlling nonpoint source of pollutants, and eventually protecting soil and water environment. Potential benefits of PAM treatment in agricultural soil and water environments have been revealed by many research and they include low cost, easy and quick application, and suitability for use with other Best Management Practices (BMPs) for NPS control. This study reviews the various applications of PAM and discusses its further potentials in agricultural environment.

• Korean Journal of Community Nutrition
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• v.7 no.4
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• pp.548-558
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• 2002

The purpose of this study was to develop a computer software program for nutritional assessment using a Semi-Quantitative Food Frequency Questionnaire (SQFFQs) and the 24-hour Recall Method. The software for the SQFFQ was divided into input, output, and database. For dietary analyses, recipe and food databases were used. The recipe database included 25 items and the food database was divided into 18 food groups. The food database was composed of 19 general nutrient items, 33 fatty acids, and 18 amino acids. The software developed in this study can be summarized as follows: 1) input items related to the individual s ages information, lifestyle, biological values, and dietary habits; 2) individualized data in percent of the Korean RDA, the energy ratios of carbohydrates, proteins and fats, the ratio of animal to plant source intakes, and the distribution of food group intakes; 3) Statistical data on the individual's information, lifestyle, biological values, and dietary intakes including the frequency of intake of cooked foods, the amounts of food, and the number of food groups, and nutrients. In the 24-hour Recall Method, the input and output consisted of the individual s information and cooked dish intakes. The individual s report included the amounts of nutrient intake according to number of meal and days, in comparison to the Korean RDA, the energy ratio for carbohydrates, proteins and fats, the ratio of animal to plant source intakes, and the distribution of food group intakes. The statistical report presented the number of food groups and foods, and the nutrient intakes. To evaluate the validity of the SQFFQ, the Spearman Rank Order Correlation and kappa values were used. As a result, correlation coefficients comparing the 24-hour Recall Method appeared to be more than 0.5, except for vitamin $B_1, B_2$, niacin, and vitamin E. The kappa values for energy and carbohydrate intakes were both 0.7, and protein, fat, vitamin C, folate, Ca, and iron intakes ranged from 0.3 to 0.7.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.5
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• pp.573-579
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• 2010

This study was conducted to determine the effects of different copper (inorganic and organic) and energy (tallow and glycerol) sources on growth performance, nutrient digestibility, gas emission, diarrhea incidence, and fecal copper concentration in growing pigs by using a 2${\times}$2 factorial design. In this trial, 96 pigs (63 d of age) were employed, with an average initial weight of 28.36${\pm}$1.14 kg. The dietary treatments were i) basal diet with 134 ppm copper (Korea recommendation) as $CuSO_4$+tallow; ii) basal diet with 134 ppm Cu as $CuSO_4$+glycerol; iii) basal diet with 134 ppm copper as CuMet+tallow; and iv) basal diet with 134 ppm copper as CuMet+ glycerol. Throughout the entire experimental period, no differences were noted among treatment groups with regard to the magnitude of improvement in ADG (average daily gain), ADFI (average daily feed intake) and G/F (gain:feed) ratios. The nitrogen (N) digestibility of pigs fed on diets containing organic copper was improved as compared with that observed in pigs fed on diets containing inorganic copper (p<0.05). An interaction of copper${\times}$energy was observed in the context of both nitrogen (p<0.05) and energy (p<0.01) digestibility. Ammonia emissions were significantly lower in the organic copper-added treatment groups than in the inorganic copperadded treatment groups (p<0.05). Mercaptan and hydrogen sulfide emissions were reduced via the addition of glycerol (p<0.05). No significant effects of copper or energy source, or their interaction, were observed in reference to diarrhea appearance and incidence throughout the entirety of the experimental period. The copper concentration in the feces was significantly lower in the organic copper source treatment group than was observed in the inorganic copper source treatment group (p<0.05). The results of this experiment show that organic copper substituted for inorganic copper in the diet results in a decreased fecal copper excretion, but exerts no effect on performance. The different energy (tallow and glycerol) sources interact with different copper sources and thus influence nutrient digestibility. Glycerol supplementation may reduce the concentrations of odorous sulfuric compounds with different Cu sources.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.31 no.2
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• pp.242-248
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• 1986

To study the effect of cold water irrigation at the reproductive growth stage of rice plants on several growth characters related to source and sink and nutrient uptake, the present experiment was carried out under the different conditions of water temperature and water depth. Deep irrigation with normal temperature water increased culm length, panicle length and panicle exsertion but with cold water resulted adversely. Most sensi-tive response in 5 cm water-depth appeared at reduction division stage and in 20 cm depth at panicle formation stage. Secondary branches and spikelets were increased in number by deep irrigation with normal temperature water, but decreased and degenerated by deep irrigation with cold water at panicle formation stage resulting in high spikelet sterility and low grain filling. Deep irrigation with normal temperature water increased the contents of total nitrogen, phosphate, potassium and silicate in leaf blades, branches and chaff. However, cold water irrigation reduced the uptake of phosphate, potassium and silicate except nitrogen particularly in deep irrigation. Ratios of phosphate, potassium and silicate to total nitrogen content were decreased by cold water irrigation. Branches seemed to have higher requirements for phosphate, potassium and silicate than leaf blades and chaff. Silicate-to-total nitrogen ratio in leaf blades, branches and chaff had significant correlations with yield showing closer relationship between yield and the ratio of silicate to total nitrogen in branches in particu-lar.

• Korean Journal of Organic Agriculture
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• v.11 no.2
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• pp.103-113
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• 2003

The chemical properties of oak tree wood vinegar and the effect of wood vinegar on the tomato seedling were investigated to apply wood vinegar efficiently to the organic - and natural farming system. On the basis of the results from chemical properties of the oak tree wood vinegar, mineral nutrient contents of wood vinegar was low. Therefore, wood vinegar could not be a suitable nutrient source for the plant growth at 500∼1000 times dilution level. which commonly used in the farming, if only wood vinegar is supplied for the nutrient source for the plant growth. The application of wood vinegar increased root growth up the 500 times dilution level while decreased shoot growth. Furthermore. the anion concentrations such as nitrate and phosphate of the plant were decreased by the application of wood vinegar while cation concentrations such as K. Ca. and Mg were increased. Phenolic compounds of wood vinegar such as chlorogenic acid and ferulic acid enhanced the root growth. Interestingly the application of ferulic acid increased both root and shoot growth at the level of 10$^{-4}$ M concentration. It indicated that the effect of wood vinegar on the production of healthy plant seedling may be due to the beneficial root growth by phenolic compounds such as chlorogenic acid and/or ferulic acid of the wood vinegar. However. the effect of the wood vinegar on the plant growth could be influenced by synergism or antagonism of different phenolic compounds in wood vinegar used. In addition. drench in the soil of wood vinegar may be more beneficial compared to foliar application for the improvement of root activity and plant growth.

• Journal of the Korean Dietetic Association
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• v.7 no.4
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• pp.426-438
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• 2001

Nutrient intake of Koreans from the 1999 Seasonal Nutrition Survey was somewhat lower than those of 1995 National Nutrition Survey or 1998 National Health and Nutrition Survey owing to the seasonal variation in amount and kind of foods eaten. In addition to the seasonal variation, low response rate of households which were surveyed twice was another reason for lower intake. Analysis of the major source of nutrients showed that intake of energy, carbohydrate, vitamin A and vitamin C was influenced by seasonal food supply pattern. And especially, vitamin A and vitamin C intake was more influenced by consumption of fruits and vegetables than other food groups. Main sources of these two nutrients were spinach and strawberry in spring, watermelon, tomato, melon and potato in summer, and grapes and pumpkin in autumn. As shown before in the report on food consumption, intake of beverages, drinks, fruits and vegetables was more influenced by season than others and these food groups affected the nutrient intake most. With the results of the 1998 National Health and Nutrition Survey, this study made it possible to estimate the average nutrient intake of the Korean population through out a year.