• Korean Journal of Soil Science and Fertilizer
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• v.33 no.5
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• pp.347-355
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• 2000

To determine nitrogen balance (Input-Output) of Korea that was asked by Joint Working Party of the Committee for Agriculture and the Environment Policy Committee, OECD, nitrogen input and output were separately investigated as followings: nitrogen input included the amounts of chemical fertilizer consumption, cattle manure production, and biological nitrogen fixation in the national scale, and nitrogen output summed amounts withdrawn by crop and pasture harvesting, and crop residue removal, and lost by denitrification. In 1997, nitrogen balance of Korea was $158kg\;ha^{-1}$ and $211kg\;ha^{-1}$ on including and excluding denitrification loss, respectively. N balance excluded N loss by denitrification and N withdrawal by crop residues on nitrogen output was $250kg\;ha^{-1}$, which OECD asked to except two items from N balance determination because participants were not enough their data. Nitrogen balance was increased to 1.7~2.3 times in 1997 compared with 70 and $162kg\;ha^{-1}$ in 1985, which calculated on the condition of including denitrification and excluding denitrification and removal of crop residues in nitrogen output, respectively. This increase was caused mainly by increasing livestock manure production and chemical fertilizer consumption together with agricultural land area decrease. Nitrogen input was composed with 59% of chemical fertilizer. 42% of cattle manure and 5% of others in 1997, and output was with 73% of crop production, 23% of crop residue withdrawal and 4% of pasture production. Average nitrogen balance excluded N loss by denitrification and N withdrawals by crop residues in 1995~1997 calculated by OECD was $253kg\;ha^{-1}$, which was the second highest rank in OECD participants following $262kg\;ha^{-1}$ of Netherlands. Japanese N balance that has similar farming system with us was $135kg\;ha^{-1}$.

• Korean Journal of Agricultural and Forest Meteorology
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• v.20 no.4
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• pp.357-365
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• 2018

This study was carried out to evaluate the weight loss rates, carbon and nitrogen dynamics of wood stakes following soil amendment treatments (CLB: compound fertilizer + lime + biochar; LB: lime + biochar) in a post-fire restoration area, Ulsan Metropolitan city, southern Korea. Soil amendments in the fire-disturbed area were applied to two-times (Mar. and Jun. 2015, 2016) during the study period. Wood stakes on Mar. 2015 were buried at a top 15cm of mineral soil in two soil amendment and control treatments of Liriodendron tulipifera, Prunus yedoensis, Quercus acutissima, Pinus thunbergii plantations and an unplanted area in the post-fire restoration area. Wood stakes were collected at Oct. 2015, Mar. 2016 and Oct. 2016 to measure weight loss rates, organic carbon and nitrogen concentrations. Weight loss rates of wood stakes were not significantly affected by soil amendment treatments. However, remaining carbon of wood stakes were lowest in the control treatment (43.7%), followed by the CLB (71.3%) and the LB (71.6%) treatments. Remaining nitrogen of wood stakes was less in the control treatment (29.7%) compared with the LB treatment (52.6%). The results indicate that carbon and nitrogen mineralization of wood stakes in post-fire restoration area were delayed by soil amendment treatments.

• Journal of Life Science
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• v.5 no.4
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• pp.190-202
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• 1995

Two oriental melons cultivars, ‘Geumssaragi Euncheon’(GSEC) and ‘House Eunchon’(HEC), were grafted onto different rootstocks and the growth, mineral contents and fruit quality were examined. The seedlings grafted onto‘Geumtozwa’rootsticks showed about 10% defected seedling loss(wilting or dwarfing0as compared to the little or no loss in the seedlings grafted onto 'Sintozwa' or 'Chamtozwa' rootstocks. The seedings grafted onto 'Sintozwa' or 'Chamtozwa' rootstocks also exhibited better vine growth as compared to the intact seedlings or the seedlings grafted onto 'Geumtozwa' rootstocks. The fruits growth, as measured by fruits length, fruit diameter and fruit fresh weight, was accelerated by the rootstocks especially by 'Sintozwa' and 'Chamtozwa' . Intact oriental melons showed the highest soluble solids content in the fruit pericarp followed by 'Chamtozwa' rootstocks. Sucrose contents were higher in the seedling grafted onto 'Sintozwa', whereas higher glucose and fructose contents were measured in intact GSEC fruits or HEC fruits on 'Chamtozwa' rootstock. As compared to the intact plants, the seedling grafted onto 'Sintozwa' rootstock showed higher N. P and K and lower Ca and Mg contents in leaves, stems, roots and fruits. 'Geumtozwa' rootstock, developed specially for oriental melons, showed very similar pattern of mineral absorption or distribution as compared to the intact plants.

• Current Research on Agriculture and Life Sciences
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• v.32 no.2
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• pp.67-73
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• 2014

Mulberry fruits were semi-dried using hot air ($60-100^{\circ}C$) or cool air ($20-40^{\circ}C$), and the effects of the drying temperature and processing time on the quality of the final dried mulberry fruits were investigated. Response surface methodology was employed to establish a statistical model and predict the conditions resulting in minimal loss of the total phenolic content (TPC) and ascorbic acid. Thus, using overlapped contour plots, the optimal conditions for producing semi-dried mulberry fruits, which reduced the moisture residue to 45% and minimized the nutrient losses of TPC and ascorbic acid, were determined for the hot-air process ($60.7^{\circ}C$ for 5.4 h) and cool-air process ($34.8^{\circ}C$ for 23.3 h). Plus, a higher drying temperature was found to lead to a faster loss of moisture and ascorbic acid, while the TPC was significantly decreased in the cool-air dried mulberry fruits due to the higher activity of polyphenol oxidase between 30 and $40^{\circ}C$.

• Korean Journal of Agricultural Science
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• v.48 no.4
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• pp.739-751
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• 2021

The thawing process is usually essential for imported pork because this product is typically distributed frozen. Consumers prefer fresh pork because discoloration, nutrient spills, and microbial contamination are high during the thawing process. The illegal act of selling frozen pork by disguising it as fresh pork through various methods can occur for the benefit of the difference in the sales price. However, there is some difficulty in securing systematic and objective data, as sensory tests are generally performed on imported pork. In the experiment conducted here, the electrical conductivity and dielectric properties of pork neck and pork belly products were measured. The amounts of change before and after freezing were compared through a statistical analysis, and a new method for determining frozen meat was proposed based on the analysis results. The weight was reduced compared to that before freezing due to the outflow of drips from the thawing process, but there was no difference in the drip loss level due to the thawing method. Vacuum packaging was found to lead to more drip loss than regular packaging, but the difference was not statistically significant. Frozen pork neck meat can be determined by measuring the electrical conductivity in the lean parts and the dielectric characteristic in the fatty parts. Frozen pork belly is determined by measuring the dielectric constant of the part closest to the outer fat layer.

• Journal of Animal Science and Technology
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• v.45 no.6
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• pp.1039-1046
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• 2003

In a trial involving 240pigs, the proximate composition, physico-chemical properites, color, amino acid composition and fatty acid composition of loin muscle were investigated in feeding various finished pig feeds. The treatments included feeding control) the low-nutrient density diet(2,960cal/kg ME, 12.25% CP, 0.41% lysine and 0.70% Ca), T1) the medium-nutrient density diet(3,220cal/kg ME, 15.50% CP, 0.87% lysine and 0.90% Ca) and T2) the hight-nutrient density diet(3,350cal/kg ME, 17.50% CP, 1.05% lysine and 0.90% Ca). The crude ash contents of T1 were significantly(p〈0.05) higher than those of control and T2. The pH$_{u}$ of T2 were significantly higher than those of control and T1, but cooking loss were significantly(p〈0.05) lower than those of control. In compositions amino acid, aspartic acid, threonine, iso-leucine and histidine of T2 were higher than those of control, but proline and glycine were significantly(p〈0.05) lower then those of control. The oleic acid(18:1) contents of control were significantly higher than those of T1 and T2, but the contents of linoleic acid(C18:2) and arachidonic(C20:4) acid were significantly(p〈0.05) lower. Inconclusion, the results of the experiments suggest that the high-nutrient density diet for pigs tended to improve the postmortem pH$_{u}$ and cooking loss.

• Asian-Australasian Journal of Animal Sciences
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• v.12 no.3
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• pp.400-410
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• 1999

Five experiments were conducted using finishing pigs (PIC L326 sires $\times$ C15 dams) to examine the effects of expander operating conditions on nutrient digestibility in finishing pigs. The effects of different expanding conditions (0, 11.7, 24.4, $32.5kg/cm^2$) for corn-SBM based diets (Exp. 1), wheat meddlings diet (Exp. 2), sorghum-SBM based diets (Exp. 3) and wheat-SBM based diet (Exp. 4). Exp. 5 was conducted as a $2{\times}4$ factorial arrangement and factors examined were 2 soy products (raw soybean and SBM) and 4 expanding conditions (0, 14.1, 28.1, $42.2kg/cm^2$). In experiment 1, total production rates (p>0.10) were similar among treatments. The amount of fines decreased (cubic effect, p<0.001) as cone pressure was increased from 0 to $11.7kg/cm^2$, with smaller differences as cone pressure was further increased to $35.2kg/cm^2$. Nutrient digestibilities increased (p<0.02) as the feed was subjected to higher cone pressures. Digestibilities of DM, N, and GE were maximized at $24.4kg/cm^2$ cone pressure. The DE of the diet expanded at 24.4 and $35.2kg/cm^2$ increased by 172 and 109 kcal/kg, respectively, compared to the diet processed at $0kg/cm^2$ cone pressure. In experiment 2, total production and screened pellets production rates were similar among the processing treatments (p>0.21). The amount of fines decreased (quadratic effect, p<0.03) by 9 kg/h as cone pressure was increased from 0 to $11.7kg/cm^2$. Digestibilities of DM (p<0.02), N (p<0.001), and GE (p<0.002) were increased as cone pressure was increased from 0 to $35.2kg/cm^2$. DM, N, and GE digestibility in the pigs fed the midds-based diet increased by 8, 13, and 10%, respectively, at the highest processing cone pressure compared to the diets without any cone pressure. In experiment 3, the conditioned mash moistures for the treatments were numerically similar around 15% moisture. As the expander cone pressure was increased from 0 to $11.7kg/cm^2$, energy consumption for the pellet mill decreased (quadratic effect, p<0.004) from 14.1 to 12.0 kWh/t. Dry matter and gross energy digestibility increased (cubic effects, p<0.006) as cone pressure was increased from 0 to $35.2kg/cm^2$ with the largest improvement occurring as cone pressure was increased from 0 to $11.7kg/cm^2$. Nitrogen digestibility increased (cubic effect, p<0.001) from 78.3 to 81.0% as the feed was subjected to the higher cone pressures, with N digestibility being maximized at $24.4kg/cm^2$ cone pressure. The DE of the diet increased (cubic effect, p<0.001) by 225 kcal/kg as cone pressure was increased from 0 to $11.7kg/cm^2$. In experiment 4, pellet moisture decreased and moisture loss increased as cone pressure was increased from 0 to $35.2kg/cm^2$. Also, starch gelatinization of the wheat-based diets increased from 16.8 to 49.1% as the diets were processed at 0 and $35.2kg/cm^2$ cone pressure. Nutrient digestibilities were not affected (p>0.18) by any increase in cone pressure. In experiment 5, pellet moisture decreased as cone pressure was increased 0 to $35.2kg/cm^2$. The amount of moisture loss for the diets expanded at $42.2kg/cm^2$ was 3.0 and 3.8% for the SBM and raw soybean (RB) diets, respectively. Starch gelatinization for the SBM diets were 19% greater than the RB diets. The RB diets had lower DM, N and GE digestibilities as compared to the SBM diets. The DE of the RB diets were lower (p<0.02) than the SBM diets. DM (p<0.06), N (p<0.02), and GE (p<0.001) digestibilities of the dietary treatments increased as cone pressure was increased 0 to $42.2kg/cm^2$.

• Korean Journal of Community Nutrition
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• v.7 no.1
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• pp.121-129
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• 2002

Osteoporosis, the typical metabolic bone disease of the elderly, is characterized by a reduction in bone mineral density (BMD) and increased fracture risk. Genetic and environmental factors are known to play a key role in bone metabolism, and diet is also considered to be one of the important factors. The purpose of the present study was to investigate the relationship among the factors affecting BMD, including stature, body weight, age, time period since onset of menopause, and biochemical markers of bone turnover in postmenopausal women. Seventy-eight postmenopausal women who visited health promotion center for health examinations volunteered to participate in this study and they were divided into two groups according to the time period since onset of menopause : women with a time period since onset of menopause of less than 5 years (Group 1) and women with a time period since onset of menopause of 5 years or more (Group 2). The demographic characteristics and dietary intake were surveyed using a questionnaire. BMDs of the lumbar spine and femoral neck of subjects were measured by dual energy X-ray absorptiometry. Serum levels of 25-hydroxy-vitamin D and parathyroid hormone (PTH), known to be indicators of bone related hormone status, were anlyzed. Serum samples were measured for calcium, phosphorus, alkaline phosphatase, and osteocalcin as bone formation indicators, and urine was analysed for deoxypyridinoline, creatinine, calcium, and sodium as bone resorption indicators. The results are as follow : The mean BMDs of the lumbar spin and femoral neck were $1.02 \pm 0.02 g/cm^2 and 0.81 \pm 0.02 g/cm^2 respectively, and the BMD level of Group 2 was significantly lower than tat of Group 1 (p<0.01, p<0.05, respectively). The mean daily intake of energy was 1838 $\pm$ 55 kcal. When nutrient intake was compared with the recommended dietary allowances (RDA) of the subjects, only calcium, vitamin A and riboflavin intake showed means lower than the RDA. The nutrient intake did not show any significant differences between Group 1 and 2 Serum and urine levels of biochemical markers of bone turnover did not show any significant differences between Group 1 and 2, and all were within the normal range. However, the PTH and deoxypyridinoline levels showed a tendency to be higher, and the osteocalcin level to be lower in Group 2 than in Group 1. Although age and years after menopause (YAM) showed negative correlations with lumbar spine bone mineral density (LBMD) (r= -0.38, p<0.001, and r= -0.26, p< 0.05, respectively), no correlation was found with femoral neck bone mineral density (NBMD). While height, body weight and body mass index (BMI) showed a positive correlation with LBMD (r= 0.32, p<0.001, r= 0.38, p<0.001, r= 0.22, p= 0.05, respectively), only body weight and BMI showed a positive correlation with NBMD (r= 0.30, p<0.01, and r= 0.27, p<0.05, respectivley). There was no significant corealtion between BMDs and the nutrient intake of subjects, except in the case of carbohydrates (r= 0.22, p<0.05). Also, serum and urine levels of bone turnover markers showed no significant correlation with nutrient intake. On the other hand, serum osteocalcin had a positive correlation with vitamin C intake (r= 0.22, p= 0.05), and urine deoxypyridinolin showed a negative correlation with niacin intake (r= -0.22, p= 0.05). Urinary na was negatively correlated with protein intake(r= -0.23, p= 0.05). The results suggested that it is difficult to prevent the decrease in bone mass among postmenopausal women eating the usual Korean diet. However, the BMDs of the lumbar spine and femoral neck were positively related to body weight ad BMI in postmenopausal women. Therefore, this study confirmed that one of the most effective ways to minimize bone loss in postmenopausal women would be to maintain an adequate body weight with balanced nutrient intake and activity in the pre-and postmenopausal periods.

• Food Science of Animal Resources
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• v.27 no.4
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• pp.387-391
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• 2007

This study was conducted to evaluate effects of dietary nutrient levels on growth performance, blood urea nitrogen, and meat quality in finishing pigs. A total of ninety six pigs ($Landrace{\times}Yorkshire{\times}Duroc$) were used in this 66 day study. Dietary treatments included 1) T1 (ME 3,441 kcal/kg, CP 16.30%, Lysine 0.93%), 2) T2 (ME 3,433 kcal/kg, CP 17.00%, Lysine 1.00% and 3) T3 (ME 3,449 kcal/kg, CP 17.00%, Lysine 1.00%). During the overall period, there were no significant differences in ADG (average daily gain), ADFI (average daily feed intake), gain/feed ratio or BUN (blood urea nitrogen) among the treatments (p>0.05). The $b^*$ value of M. longissimus dorsi muscle color significantly increased (p<0.05) with T3 treatment compared to T2 treatment. However, there were no differences in the $L^*\;and\;a^*$ values, pH, M. logissimus dorsi area, drip loss, cooking loss, TBARS and WHC (water holding capacity) for pigs fed the various treatments (p>0.05). The total feed cost per kg of weight gain was not significantly different among the various dietary treatments (p>0.05). In conclusion, these results show no effects of dietary nutrient levels on growth performance and meat quality in finishing pigs, and also suggest that a high nutrient density diet may not be a beneficial feeding strategy for finishing pigs in terms of cost.

• Korean Journal of Environmental Agriculture
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• v.36 no.3
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• pp.147-153
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• 2017

BACKGROUND: Soil water content strongly depends on weather condition and irrigation, and it could influence on crop nutrient use efficiency. This study was performed to assess nutrient uptake of soybean by soil water condition. METHODS AND RESULTS: In this study, nutrient leaching and crop uptake as affacted by water management practice was investigated using weighing lysimeter which is located in National institute of agricultural science, Wanju, Jeonbuk province from June 2015 to October 2016. Water supply for soybean (cv. Daewon) was managed with irrigation and rainfall. Nitrate leaching was greatest in the rainfall treatment at early July 2016. Yield of soybean in the rainfall treatment was only 25% compared to the irrigation due to the drought at flowering and podding period. The uptake of nitrogen was considerably reduced by drought whereas the uptake of phosphorus and potassium was less affected by drought. CONCLUSION: It was proven that nitrogen loss and uptake were dependent on soil water condition. Therefore, irrigation water management to maintain available soil moisture capacity is critical to nitrogen uptake and yield of soybean.