• Korean Journal of Community Nutrition
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• v.1 no.1
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• pp.28-40
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• 1996

This study was conducted to evaluate the nutrition quality of the commercial infant formulas and to seek the solution to the establishment of the standard of nutrient requirements for infant formula in Korea. Nutrition informations were obtained from the labels of nineteen commercial infant formulas manufactured by 3 different companies, and the actual amounts of some nutrients were analyzed and compared to the labeled amounts. In addition, the nutrient composition of the commercial infant formulas was compared to the composition of breast milk, RDA for infants, and Codex standard for infant formula. The kind of minerals, vitamins and special components added to the commercial infant formulas were the major differences among 3 manufacturers. For some nutrients, the analyzed amounts were lower than the labeled amounts. In addition when different batches of the same kind of infant formula were analyzed, the large variations in the amounts of certain nutrients were noted. These data suggest that the nutrition labeling informations need to be validated, and nutrients added to the formulas are to be homogenized thoroughly. In order to solve these problems, therefore, like other countries, we need to establish the standard of nutrient requirements for infant formulas. Considering the available data on breast milk composition, RDA for infants and coordination with the international standard, we suggest the adoption of the Codex standard for infant formula may be the best way to manage the nutrition quality of commercial infant formulas at the present time.

• Korean Journal of Community Nutrition
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• v.2 no.4
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• pp.624-632
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• 1997

This study was conducted to evaluated the nutrition quality of the commercial supplementary foods for infants and young children and to seek a solution to the establishment of standards of nutrient requirements for supplementary foods in Korea. Information on food ingredients, nutrient contents, claims about usefulness of food components and instructions for feeding preparation were obtained from the labels of 33 commercial supplementary foods manufactured by 4 different domestic companies. According to the standard of supplementary foods for infants and young children described in the Korean Food Code, the commercial supplementary foods were categorized into two different types, weaning food and baby food. All the commercial weaning foods were in powder form and mainly composed of cereals, whereas all the baby foods were mainly composed of fruits in the form of canned juice. The weaning foods contained more nutrients than the baby foods did, and the nutrient levels of the weaning foods expressed as nutrient density on energy basis were higher than the RDA for infants aged 5 to 11 months, suggesting that the commercial weaning foods provide adequate amounts of nutrients. If one followed the instructions for feeding preparation appearing on the label, however, recommended amounts of intake of the weaning foods would provide too much energy as well as nutrients. There were many differences in nutrient standards of weaning foods between the Korean Food Code and Codex international food standard. In conclusion, the establishment of standards for nutrient requirements for the supplementary foods requires significant scientific studies on what nutrients are the most inadequate in Korean infants and young children feeds and what levels of nutrients should be added to the foods in order to supplement their nutrition. In addition, it is very important to have a strong scientific basis to support our standard when discrepancies exist between our standard and the international standard. (Korean J Community Nutrition 2(4) : 624-632, 1997)

• 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 ${ha}_{-1}$

• Journal of Korea Foresty Energy
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• v.24 no.1
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• pp.13-27
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• 2005

In order to design new fertilizers for forests, seedlings of Pinus densiflora, Larix leptolepis Betula platyphylla var. japonica, and FQuercus acutissima were treated with different fertilizers, and nutrient concentrations in seedling components were analyzed. In general, nitrogen (N) and phosphorus (P) concentrations in seedling components increased after N and P application. Potassium (K) concentration in seedling components of Pinus densiflora and Quercus acutissima increased after N, P and K application. However, there were no significant changes in calcium (Ca), sodium (Na) and magnesium (Mg) concentrations. Nitrogen and P concentrations in seedling components increased with the amount of solid combination fertilizer and UF combination fertilizer. Potassium concentration for Pinus densiflora and Na and Ca concentrations for Larix leptolepis also increased with the amount of combination fertilizers. However, nutrient concentrations in seedling components showed no significant changes with different combination fertilizers.

• Journal of Microbiology and Biotechnology
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• v.7 no.5
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• pp.352-355
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• 1997

The promoter region of the pupA gene of Pseudomonas putida WCS358 was fused with the structural genes for bioluminescence (luxCDABE) from Vibrio fischeri, and the resulting fusion plasmid harbored by the WCS358 host. The pup-lux fusion gene was then used for quantitative analysis of the iron-dependence of pupA promoter activity. Factors affecting bioluminescence produced by the pup-lux bioreporter were found to be cell activity, iron-chelator concentrations, Fe(III) concentrations, and nutrient components. Light production rates of the pup-lux bioreporter were inversely dependent upon iron molecules when $FeCl_3$ concentrations were between $10^{-2}$ and 1 ${\mu}M$ in nutrient-poor minimal media, and between 0.1 and 10 mM in nutrient-rich complex media.

• Korean Journal of Pharmacognosy
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• v.20 no.4
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• pp.243-253
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• 1989

Anatomical and physico-chemical properties of some nutrient and tonic crude drugs have been estimated and compared. Resin duct and druse crystal were observed more in Acanthopanax Cortex than in Ginseng Radix. Bast fiber bundle and solitary crystals were abandantly present in Glycyrrhizae Radix. Mucilage crude drugs contained mucilage ducts and bundles of raphides as common components and their arrangements of vascular bundles were different. TLC analysis showed different patterns of saponin, flavonoid, ${\gamma}-aminobutyric$ acid and sitosterols.

• Magazine of the Korean Society of Agricultural Engineers
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• v.44 no.5
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• pp.106-115
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• 2002

The objective of this study was to evaluate the GLEAMS-PADDY model by applying it to estimate nutrients loading from paddy-field areas. Field data from Soro region of Chungbuk province during May to September 1999 were used for model application. Field data collected include the amounts of rainfall, irrigation water, drainage water, ET, and Percolation in hydrology Part. T-N and T-P concentrations in the rain water, irrigation water, ponded water, drainage water and percolated water were measured. The comparisons of observed and simulated water balance components and nutrient concentrations showed reasonably good agreements and the GLEAMS-PADDY model may be used to simulate nutrients loading from paddy fields. Futher research was suggested to include the erosion submodel in the GLEAMS-PADDY model to better simulate the nutrient behavior. In addition, the pesticide submodel also recommended to be included in order to simulate the various pesticide applied in paddy fields.

• Journal of The Korean Society of Grassland and Forage Science
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• v.7 no.2
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• pp.97-102
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• 1987

To find out the nutrient contents of temperate grasses on the south and north slope, a field experiment was conducted with five forage species of Dactylis glomerata, Festuca arundinacea, Phleum pratense, Agrostis gigantea and Trifolium repens. It was treated by randomized block design with 4 replications and lasted from September, 1983 to October, 1986 in Suweon. The results obtained are summarized as follows: 1. Mean chemical compositions except NFE and crude fiber of the forage species on the south slope were a little more contented than that of north. But all crude components were significant difference among the species on the south and north exposure. 2. Production of TDN (total digestible nutrient), StE (starch equivalent) ME (metabolizable energy) and NEL (net energy lactation) of different grass species on the north slope were much more increased by 5-30% per ha (Dactylis glomerata by 5-876, Festuca arundinacea by 5%, Phleum pratense by 24-26% and Agrostis gigantea by 25-30%) than that of same grasses on the south, however, those of Trifolium repens were much more increased by 4 1-42% per ha in the south. 3. Mineral contents, Ca/P ratio and K/ (Ca + Mg) equivalent ratio of the species were slightly different between the exposures. But considering the factors of occuring grass tetany, those of the forage species on the north slope were better than that of same species on the south.

• Journal of Korea Foresty Energy
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• v.23 no.1
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• pp.1-18
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• 2004

Effects of nitrogen and phosphorus fertilization on aboveground biomass and distribution of nutrient content in tree components were determined in adjacent 41-year-old plantations of Pinus rigida Miller and Larix kaempferi Gordon on a similar soil in Yangpyeong, Gyeonggi Province. Fertilizer was experimentally applied at the three levels [control(C), 200 N kg/ha+25 P kg/ha(LNP), and 400 N kg/ha+50 P kg/ha(HNP)] in June, 1996. The results obtained from this study were summarized as follows: Total aboveground biomass of P. rigida and L. kaempferi stands was 149, 145ton/ha for control, 166, 149ton/ha for LNP, and 152, 170ton/ha for HNP, respectively, and did not differ between the tree species. Aboveground biomass of P. rigida and L. kaempferi plantations were distributed as follows: stemwood>branch>stembark>foliage. Biomass of understory vegetation was 1,111kg/ha for P. rigida and 907kg/ha for L. kaempferi, and comprised 0.6～0.7% of the total aboveground biomass of the plantations. The concentrations of all nutrients(N, P, K, Ca, Mg) were generally higher in L. kaempferi than in P. rigida because of high nutrient uptake characteristics of Larix spp. Nutrient concentrations in tree components of P. rigida and L. kaempferi plantations were not significantly different among treatments, whereas they were significantly different between species and among tree components. The nutrient concentration in tree components of both tree species decreased in order of foliage>branch>stembark>stemwood. The contents of all nutrients were higher in the fertilized plots than in the control plots, generally the highest in LNP for P. rigida and in HNP for L. kaempferi. Total nutrient(N+P+K+Ca+Mg) contents of aboveground biomass were 703kg/ha for P. rigida and 869kg/ha for L. kaempferi, respectively.

• Korean Journal of Agricultural Science
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• v.43 no.4
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• pp.537-546
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• 2016

The development of models for agriculture systems, especially for crop production, has supported the prediction of crop yields under various environmental change scenarios and the selection of better crop species or cultivar. Crop models could be used as tools for supporting reasonable nutrient management approaches for agricultural land. This paper outlines the simplified structure of main crop models (crop growth model, crop-soil model, and crop-soil-environment model) frequently used in agricultural systems and shows diverse application of their simulated results. Crop growth models such as LINTUL, SUCROS, could provide simulated data for daily growth, potential production, and photosynthesis assimilate partitioning to various organs with different physiological stages, and for evaluating crop nutrient demand. Crop-Soil models (DSSAT, APSIM, WOFOST, QUEFTS) simulate growth, development, and yields of crops; soil processes describing nutrient uptake from root zone; and soil nutrient supply capability, e.g., mineralization/decomposition of soil organic matter. The crop model built for the DSSAT family software has limitations in spatial variability due to its simulation mechanism based on a single homogeneous field unit. To introduce well-performing crop models, the potential applications for crop-soil-environment models such as DSSAT, APSIM, or even a newly designed model, should first be compared. The parameterization of various crops under different cultivation conditions like those of intensive farming systems common in Korea, shortened crop growth period, should be considered as well as various resource inputs.