• Journal of Ecology and Environment
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• v.39 no.1
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• pp.51-60
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• 2016

This study was conducted to examine litter fall, litter decomposition, and a short-term nutrient (C, N, P, K, Ca, and Mg) status for one year at various levels of basal area (21.4, 27.0, 30.8, 37.0, 42.1, and 46.7 m² ha^-1) in approximately 40-yearold red pine (Pinus densiflora S. et Z.) stands in the Hwangmaesan mountain forest in Korea. Monthly fluxes of litter fall components such as needles, broad leaves, branches, bark and total litter fall followed a similar pattern at various levels of basal area. Mean annual needle, bark and total litter fall fluxes were positively correlated with increased basal area (p<0.05), but the woody litter such as branches and cones was not correlated with basal area. Carbon and K concentrations of needle litter were negatively correlated with increased basal area, while nutrient (C, N, P, K, Ca, and Mg) fluxes were positively correlated with the basal area treatments. Remaining mass, N and P concentration and remaining N and P stocks in decomposing needle litter were not affected by the basal area. However, the concentration and stocks remaining of K, Ca, and Mg from decomposing litter were positively correlated with increased basal area during the initial three months of decomposition. The results indicate that basal area has an impact on nutrient cycles through change in litter fall and litter decomposition processes; thus, the dynamics of nutrient cycles based on a stand scale could differ considerably with different levels of basal area in red pine stands.

• Nutrition Research and Practice
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• v.2 no.2
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• pp.130-133
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• 2008

This study was conducted to investigate the effects of lecithin, mono-glyceride and mono-diglyceride on apparent total tract and ileal nutrient digestibilities in nursery pigs. Twenty [(Landrace$\times$Yorkshire)$\times$ Duroc] barrows were surgically fitted with simple T-cannulas. Dietary treatments included 1) CON (basal diet: soy oil), 2) LO (lecithin 0.5%), 3) MO (mono-glyceride 0.5%), 4) MG (mono-glyceride 1.0%) and 5) MDG (mono-diglyceride 1.0%). In apparent total tract nutrient digestibility, dry matter (DM) and gross energy (GE) digestibilities of MDG treatments were higher than LO and MG treatments (p<0.05). In nitrogen (N) digestibility, LO treatment showed the lowest compared to others (p<0.05). The digestibility of crude fat was higher in MDG treatment than CON and LO treatments (p<0.05). In apparent ileal nutrient digestibility, DM digestibility was higher in MDG treatment than LO and MG treatments (p<0.05). GE digestibility was higher in MDG treatment than LO, MO and MG treatments (p<0.05). N digestibility of MDG treatment was greater than LO treatment (p<0.05). Also, the digestibility of crude fat was higher in MDG treatment than CON and LO treatments (p<0.05). In conclusion, mono-diglyceride can increase apparent total tract nutrient and apparent ileal nutrient digestibilities of DM, GE, N and crude fat.

• Journal of Bio-Environment Control
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• v.14 no.3
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• pp.174-181
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• 2005

Experiments were carried out to develop an optimal nutrient solution for the single-stemmed rose (Rosa hybrida L.) 'Red velvet' in a closed aeroponic system. Plants were grown in 1/3, 1/2, 1, or 3/2 strength of the nutrient solution of National Horticultural Research Station in Japan (NHRS). Significantly less changes of pH and EC ($dS{\cdot}m^{-1}$) in the drainage were observed in 1/2 strength treatment as compared to other treatments. The $NO_3-N$, K, Ca, and Mg concentrations in the drainage solution of 1/2 strength treatment were maintained at optimal levels. These results indicated that the rose uptakes of both nutrients and water was more stable than those in other concentration. The concentration of macronutrients in nutrient solution were adjusted based on the ratio of nutrient:water (n/w) taken up by plants grown in the 1/2 strength solution. The composition of the new solution (classified the University of Seoul (UOS) solution) was as follow; $NO_3-N$ 8.8, $NH_4-N$ 0.67, P 2.0, K 4.8, Ca 4.0, Mg 2.0 $me{\cdot}L^{-1}$. To further evaluate new solution on crop growth, the rose 'Red Velvet' was grown again in l/2, 1, and 2 strength UOS solution to compare with 1.0 strength PBG (proefstion voor bloemisterij en glasgroenpe) solution. Overall the plant growth, including the stem length and number of five-leaflet leaves was higher in 1.0 strength of UOS solution than other treatments. Results presented in this study indicate that the nutrients in the UOS solution are well balanced for the single-stemmed rose in the closed aeroponic system.

• Journal of Nutrition and Health
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• v.32 no.1
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• pp.10-16
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• 1999

This study was conducted to figure out the differences of the BMI, blood lipids, blood pressure and nutrient intakes by serum insulin concentration among adults in Korea. Ninety-three subjects(male : n=37, female : n=56) participated in this study. The subjects were grouped by serum insulin concentrations into two groups-hyperinsulinemia group(n=17) and normoinsulinemia group(n=76). Anthropometric measurements, blood lipid profiles, blood pressure, oral glucose tolerance test, and daily nutrient intakes were analyzed. And serum glucose and insulin secretion pattern as shown through and oral glucose tolerance test were performed. BMI (p<0.05) and WHR(p<0.01) were significantly higher in hyperinsulinemic group than in normoinsulinemia group. There was no differences in fasting blood glucose level between groups, but total glucose area (p<0.001) and insulin glucose resistance(p<0.001) were significantly higher in hyperinsulinemia group than in normoinsulinemia higher in hyperinsulinemia group, but HDL-cholesterol(p<0.05), and systolic blood pressure(p<0.05) were significantly higher in hyperinsulinemia group, but HDL-cholesterol(p<0.001) was significantly lower in hyperinsulinemia group. They showed significant differences in energy, carbohydrate, potassium, riboflavin, niacin and dietary fiber intakes(p<0.05), the intake of those nutrients were low in normoinsulinemia group. Further investigation is necessary to determine the effects of amounts and types of carbohydrate and dietary fiber on serum insulin concentrations.

• Journal of Korean Society on Water Environment
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• v.28 no.4
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• pp.551-560
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• 2012

The objectives of this study were to elucidate spatio-temporal heterogeneity of water chemistry and develop empirical models using trophic variables in Daechung Reservoir during 2005-2010 along with in situ tests of nutrient enrichment bioassays (NEB). The relations of water quality parameters in regard to precipitation showed that seasonal and interannual fluctuations of biological oxygen demand (BOD), total nitrogen (TN) and pH were minor, whereas conductivity, suspended solids (SS), and total phosphorus (TP) were largely varied in response to the magnitude of rainfall. The CHL maxima occurred immediately after the spate of TP during the high flow, indicating that phytoplankton growth was directly controlled by phosphorus. Empirical linear models of CHL-TP indicated that the variation of CHL in premonsoon was accounted 60% ($R^2$ = 0.60, p < 0.05, n = 54) by TP. In the mean time, empirical models of annual CHL-TN showed that the variation of CHL was weakly accounted ($R^2$ = 0.16, p < 0.001) by TN and more strongly ($R^2$ = 0.44, p < 0.001) by TP. Thus, the variation of CHL was more explained by the variation of TP than TN. In situ tests of Nutrient Enrichment Bioassays (NEBs) showed that the growth of CHL was greater in the P-treatments (as $PO_4-P$) than the control and N-treatment (as $NO_3-P$). Overall, our results suggest that phosphorus was aprimary limiting nutrient controlling the seasonal phytoplankton growth, based on the in situ experiments of NEBs.

• Journal of Korean Society of Water and Wastewater
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• v.26 no.6
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• pp.833-840
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• 2012

This study aimed to investigate growth rate and nutrient removal efficiency of Chlorella vulgaris according to nitrogen sources and frequency of pH adjustment. Nitrogen and phosphorus removal efficiencies were evaluated in the three different conditions using $NO_3{^-}$, $NH_4{^+}$ as a sole nitrogen source and mixed condition. Initial nutrient concentrations in artificial wastewater were 30 mg-N/L and 3 mg-P/L similar to secondary wastewater effluent. When nitrogen source was $NO_3{^-}$, there was no inhibition on the growth of C. vulgaris with adjusting pH every 24 hr while growth inhibition occurred with $NH_4{^+}$ caused by pH drop. N, P removal efficiencies were no significant depending on the nitrogen sources. As pH was adjusted to 7 by pH-stat, growth rate and nutrient removal efficiencies were increased compared to adjusting pH every 24 hr, however, growth rate and nutrient removal efficiencies were no significant depending on the nitrogen sources.

• Journal of Forest and Environmental Science
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• v.26 no.1
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• pp.17-23
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• 2010

The present study was conducted to quantify wood and leaf litter decomposition and nutrient release of a dominant tree species, Tectona grandis Linn. F. in a tropical dry deciduous forest of Rajasthan, Western India. The mean relative decomposition rate was maximum in the wet summer and minimum during dry summer. Rainfall and its associated variables exhibited greater control over litter decomposition than temperature. The concentrations of N and P increased in decomposing litter with increasing retrieval days. Mass loss was negatively correlated with N and P concentrations. The monthly weight loss was significantly correlated (P < 0.05) with soil moisture and rainfall in both wood and leaf litter. Tectona grandis was found to be most suitable tree species for plantation programmes in dry tropical regions as it has high litter deposition and decomposition rates and thus it has advantages in degraded soil restoration and sustainable land management.

• Korean Journal of Environmental Agriculture
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• v.19 no.3
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• pp.247-251
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• 2000

This study was conducted to investigate tissue nutrient contents and salt accumulation in plastic house soils cultivating lily, rose and carnation. The soil tested had high total salts, available phosphate and exchangeable potassium. The soil cultivating rose had highest salt concentvation followed by chose of carnation and lily. Tissue nutrient contents of lily were higher than chose of carnation and rose. In comparison among cultivars, the nutrient contents were as follows; 'Snow Qeen'>'Le Reve'>'Casa Blanca' in lily; 'Marina'>'Super star'>'Mary Devor'>'Madelon' in carnation; and 'Cocktail'> 'Marina'>'Maderon' in rose. The range of the nutrient contents were: T-N: $1.66\;{\sim}2.35%$, K: $1.73{\sim}2.23%$, Zn: $2.13{\sim}6.43\;mg/kg$, Cu: $3.79{\sim}13.89\;mg/kg$ in carnation; T-N: $0.79{\sim}1.65%$, P: $0.18{\sim}0.44%$, Ca: $0.59{\sim}1.26%$, Mg: $0.21{\sim}0.46%$, Zn: $23.65{\sim}90.30\;mg/kg$, Cu: $0.99{\sim}4.62\;mg/kg$ in lily; and T-N: $0.75{\sim}1.62%$, P: $0.17{\sim}0.30%$, K: $1.60{\sim}2.91%$, Ca: $0.64{\sim}0.94%$, Zn: $24.57{\sim}48.31\;mg/kg$, Cu: $3.10{\sim}9.08\;mg/kg$ in rose. The amount of nutrients uptake per plant was high in order of: K > T-N > Ca > Mg in lily; and T-N > K > Ca > P > Mg in rose.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.7
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• pp.1010-1016
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• 2000

Effect on the bio-mass and nutrient yield of Lemna perpusilla Torry was studied at two nutrient loading frequencies. Six polythene sinks ($6{\times}2{\times}0.5m^{3}$ area) randomly allocated to two treatments having three sinks in each treatment. Each sink containing $6{\times}2{\times}0.35m^{3}$ water body, was changed either daily with 12.6 kg anaerobically fermented cattle manure (effluent) or with 76 kg efluent at six-day interval. Media Kjeldhal-N (40 vs. 36 mg/L; p>0.05) and $NH_3$-N (9 vs 7 mg/L; p<0.05) concentration were higher in daily charged sinks than those charged at six-day interval. However, temperature ($28.48{^{\circ}C}\;vs.\;28.60{^{\circ}C}$) and pH (6.82 vs. 6.84) were sinilar in both groups of sinks. Biomass (93 vs. $80g/m^{2}/d$) and crude protein (1.24 vs. $1.11g/m^{2}/d$) yield were non-significantly (p>0.05) higher in the daily charged than 6-d interval charged ponds. However, dry matter (4.52 vs. 4.15%), organic matter (83 vs. 84%), crude protein (31.4 va. 29.6%) and organic carbon (47 vs. 47%) content were similar in both daily and 6-d interval charged ponds. There were no apparent relationships between the crude protein content of Lemna and the media Kjeldhal-N or $NH_3$-N concentration apparently due to saturated level of nutrient (N in particular). It was concluded that with the level of effluent used for two treatments, nutrient-loading frequency had no significant effect on the biomass and protein yield of Lemna. Technique described here can be used for year-round duckweed production from fermented cattle manure for feeding poultry/fish in smallholder production system.

• Korean Journal of Environmental Agriculture
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• v.42 no.2
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• pp.152-158
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• 2023

This study was conducted to evaluate the effects on soil chemical properties and plant growth after applying soldier fly compost (SFC). Treatments were as follows. No fertilizer (NF), control, SFC1 (SFC 250 kg/10a), SFC2 (SFC 500 kg/10a) and SFC3 (SFC 1,000 kg/10a). As compared to control in the pot test, organic matter (OM) and exchangeable sodium (Ex-Na) of SFC3 treatment were increased, and growth and nutrient uptake of young radish were not significantly different. Correlation coefficient between soil chemical factors like total nitrogen (T-N), OM, and CEC and uptake of nitrogen (N) and phosphorus (P) was significantly positive (p≤0.05). Compared to control in the field test, electrical conductivity, T-N, OM, Av.-P₂O₅, and CEC was increased, and lettuce growth was not significantly different. Correlation coefficient between application amount of SFC and T-N, OM, and Av.-P₂O₅ was significant positively (p≤0.05). These results indicated that the application of SFC improved nutrient availability of soil by increasing OM and CEC.