• Journal of Nutrition and Health
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• v.52 no.6
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• pp.581-592
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• 2019

Purpose: This study investigated major dietary patterns among healthy Korean adults using cluster analysis and analyzed the relationship between energy intake and skeletal muscle mass. Methods: This study was conducted using the data from the 2008 ~ 2010 Korea National Health and Nutrition Survey. The data of 7,922 subjects aged 30 years and over, without any missing values, were included in the final analysis. K-means cluster analyses were conducted to identify the dietary patterns of the study subjects, which were based on the energy intake from 21 food groups using a 24-h recall method. The changes in energy intake with each dietary pattern, according to quartiles of skeletal muscle mass, were investigated. Results: Three dietary patterns were identified for both men and women: 'Flour, Animal fat', 'White rice' and 'Healthy mixed diet'. The association between energy intake and skeletal muscle mass for both men and women was significant only in the 'White rice' dietary pattern. In the 'White rice' pattern, the energy intake increased up to > 300 kcal from the lowest to the highest quartile of skeletal muscle mass after adjustment for covariates. Within the 'White rice' pattern, skeletal muscle mass was linearly associated with energy intake in all the age groups in men. Conclusion: Energy intake was significantly associated with changes in skeletal muscle mass only in the 'White rice' pattern. Furthermore, the degree of association between the change in skeletal muscle mass and energy intake differed according to gender. These results indicate that the association between skeletal muscle mass and energy intake may be specific to Korean people who are accustomed to a traditional Korean diet.

• Journal of Life Science
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• v.23 no.5
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• pp.698-702
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• 2013

It is known that black sticky rice with giant embryo (BSRGB, Milyang 263) and giant embryo rice (GER) contains higher levels of GABA than rice. Therefore, feeding BSRGB, GER, or rice freely to C57BL/6 mice with two-hour alcohol intake for 16 days was investigated. For two-hour alcohol intake, a repeated measure ANOVA (three treatment groups repeated across 16 days; 8 two-day blocks) yielded a significant group by block interaction (df=16, F=3.109, p=0.004). The independent t-test showed that significant suppression of two-hour alcohol intake was observed when subjects were administered with BSRGB, compared with the rice alone across all the two-day blocks (p<0.05). The paired t-test revealed that a significant suppression of two-hour alcohol intake was observed starting 4 to 16 days after freely feeding with BSRGB compared to before feeding. However, there is no significant difference in the two-hour alcohol intake observed between the before and after administration of rice. A repeated measure ANOVA revealed no significant group by block interaction for 22-hour water intake and body weight. However, a repeated measure ANOVA revealed a significant grouping by block interaction for food intake. These results indicate a change of two-hour alcohol intake is presumably caused by GABA, which is found in higher levels in BSRGB than in rice.

• Korean Journal of Soil Science and Fertilizer
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• v.24 no.4
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• pp.302-305
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• 1991

Six low-molecular-weight organic acids from decomposing plant residues were analyzed, which were formic, acetic, succinic, malic, tartaric, and citric acids. Straws of rice, barley, wheat, and rye were put under acid- hydrolysis after decomposition for different periods of time. The contents of organic acids in the hydrolysates were determined. 1. The relative molarity of a low-molecular-weight organic acid varies with the passage of the time of decomposition. 2. In general, formic and acetic acids were the major low-molecular-weight organic acids in all samples. 3. Malic acid was found to be only in a trace amount in rice and barley straws, and in their decomposed residues. 4. The relative molarities of total monocarboxylic acids(formic and acetic) increased with the progressing time of decomposition, far exceeding those of dicarboxylic and tricarboxylic acids combined together. 5. Formic and acetic acids were compensatory for each other and they were supposed to persist for a long time in soil environment.

• Korean Journal of Soil Science and Fertilizer
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• v.29 no.2
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• pp.124-129
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• 1996

This experiment has been conducted to find out a effective decomposition method of popped rice hulls which are hard to be decomposed in vitro. It was found that the C/N ratio of 35 was better than the C/N ratio of 20 for improving the decomposition ratio of popped rice hulls. The addition of rice bran accelerated the decomposition of popped rice hulls. The real decomposition rate of popped rice hulls for 10 days was merely 8 percent. This poor decomposition ratio seemed to be come from the chemical constituent of rice hull which has 20 percent of silica content. It was considered that the addition of rice bran speeded up only the decomposition of bran itself by increasing the number of microorganisms. It was also observed that color changes developed from the decomposition of rice hulls proved not to be a yardstick for the degree of decomposition.

• Korean Journal of Agricultural Science
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• v.2 no.1
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• pp.61-100
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• 1975

This study has been made to find out the possibilty of successfully using the following $K_2O$ recommended equation $K_2O\;kg/10a=(Ko/\sqrt{Ca+Mg}-Ks/\sqrt{Ca+Mg})sqrt{Ca+Mg}.\;47.\;B\;D$. where $Ko/sqrt{Ca+Mg}=0.03518+0.0007658\;Sio_2/O.M$. $K_Ssqrt{Ca+Mg}$=Exchangeable K me/100g/$\sqrt{Total\;soluble(Ca+Mg)me/100g\;in\;Soil}$ B. D. =Bulk density of top soil, when the dose of Nitrogen for rice is estimated from the following equation: $N\;kg/10a=(4.2+0.096\;SiO_2/O.M).F$ where $F=0.907+0.263x-0.013x^2$ $SiO_2/O.M=(available\;SiO_2=ppm)/(organic\;matter\;%)$in soil For this. two field experiments. one in sandy and the other in clay paddy soil. have been conducted using 3 levels of wollastonite (0, 500, 100kg/10a) as main treatments; 3 levels of $K_2O$ application were used as sub-plots. These were as follows : (1) 8kg of $K_2O$/10a regardless of the K activity-$K/\sqrt{Ca+Mg}$; (2) kg of $K_2O$/10a estimated from the above equation. and (3) same as (2) above plus additional 30% of $K_2O$. The dose of N kg/ 10a was determined from the above equation based on the value of $SiO_2$/O.M. ratio in each treatment. There were three replications. The leading variety of rice in Chung Chong Nam Do area. Akibare (introduced from Japan) was used. The data obtained. through soil and plant analysis and growth and yield observations. have been throughly examined to attain the following summarized conclusions. 1. The nitrogen dose. estimated from the above equation. was in excess for optimum growth of the rice variety Akibare; indicating the necessity of modification onthe value of "F" or the constants in the equation. The concept of using $SiO_2$/O.M. in the equation was shown to be applicable. 2. The dose of potash. estimated from the respective equation given above. also was in excess of the rice requirements indicating the necessity of minor change in the estimation of $Ko/\sqrt{Ca+Mg}$ value and some great modification in the calculation of $Ks/\sqrt{Ca+Mg}$ value for the equation; however the concept of using $K/\sqrt{Ca+Mg}$ as a basis of $K_2O$ recommendation was shown to be quite reasonable. 3. It was found. from the correlation study using the data of paddy yield and amount of $K_2O$ absorbed by rice plants that the substitution of the value of $Ks/\sqrt{Ca+Mg}$ in the equation for the vaule $Ks/\sqrt{Ca+Mg}=0.037+0.78K\;me/100g$ soil was much more applicable than using the value calculated from the data of soil and wollastonite analysis.

• Korean Journal of Agricultural and Forest Meteorology
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• v.16 no.2
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• pp.137-145
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• 2014

Rice-barley double cropping system is typical in southwestern part of South Korea. However, the information of carbon dioxide ($CO_2$) exchange for barley growing season has still limited in comparison with rice. Using the eddy covariance (EC) technique, seasonal variation of $CO_2$ exchange was analyzed for the barley growing season at a rice-barley double cropping field in Gimje, Korea. The effects of environmental factors and biomass on the $CO_2$ flux also were investigated. Quality control and gap-filling of flux data were conducted before this analysis and investigation. The results indicated that $CO_2$ uptake increased rapidly at tillering stage and maximum net ecosystem exchange of $CO_2$ (NEE) occurred at the early of May, 2012 ($-11.2gCm^{-2}d^{-1}$), when the heading of barley occurred. NEE, gross primary production (GPP), and ecosystem respiration (Re) during the barley growing season were -348.0, 663.3, and $315.2gCm^{-2}$, respectively. In this study, an attempt has been made to measure NEE, GPP, and Re with the help of the EC system for the barley growing season for the first time in Korea, focusing on $CO_2$ exchange between the biosphere and the atmosphere.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.61 no.2
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• pp.79-86
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• 2016

The late-maturing black rice cultivar Shinnongheugchal from Jeollabuk-do Agricultural Research and Extension Service was used as the plant material for estimating growth characters, quality and yield from the vegetation period to harvest age. This study was performed to select an optimum combination of nitrogen level and planting density for the maximum yield of Shinnongheugchal. The plant height, number of tillers, and SPAD index were higher when the combination of 70 hills per $3.3m^2$ and 13 kg/10 a nitrogen level was used at 30 days after transplanting. The heading date for the combination of 70 hills per $3.3m^2$ and 15 kg/10 a nitrogen level, and 80 hills per $3.3m^2$ and 15 kg/10 a nitrogen level was August 22. The heading date for the other combinations was August 21. The combination of 70 hills per $3.3m^2$ and 13 kg/10 a nitrogen level yielded the highest number of tillers at 40 days after flowering. Even though the lodging index was increased with increasing nitrogen levels, field lodging did not occur until harvest time. Seed nitrogen concentration in the combination of 70 hills per $3.3m^2$ and 13 kg/10 a nitrogen level showed a significant difference when compared with the other combinations. The black rice yield varied significantly, and the highest yield was observed in the combination of 70 hills per $3.3m^2$ and 13 kg/10 a nitrogen level. The yield was significantly correlated with seed nitrogen concentration. The maximum yield was estimated to be 14.67 kg/10 a nitrogen level by using the regression equation. On average, the coloring degree of the black rice was higher at planting density of 70 hills per $3.3m^2$ than at 80 hills per $3.3m^2$. The highest yield of perfect black rice was obtained using the combination of 70 hills per $3.3m^2$ and 13 kg/10 a nitrogen level. Our findings demonstrate that a nitrogen level of 13-14 kg/10 a can be used to obtain the maximum yield from Shinnongheugchal with yield, cyanidin 3-glucoside content, and perfect black rice yield as the standard.

• Korean Journal of Soil Science and Fertilizer
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• v.35 no.3
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• pp.162-168
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• 2002

The silica uptake of rice plant(Oryza sativa L.) and a potential capacity of paddy soil as a source of silica supply for rice plant was studied under field experimental condition. Amount of Si from irrigation water, rainfall, which was a source of silica supply, and percolating rate of water through paddy soil profile as a source of silica loss from paddy soil, was investigated. Rice plants were grown in three different conditions, which included Control as non-fertilized, RDA's recommandation(NPK, Urea-Fused phophate-Potassium chloride=$110-45-57kg\;ha^{-1}$) and RDA's recommandation with supplement of silicate fertilizer(NPK+Si, Urea-Fused phosphate-Potassium chloride+Si=$110\;N-45\;P_2O_5-57\;K_2O+267.2\;Si\;kg\;ha^{-1}$). An amount of silica supply from rainfall was $0.5kg\;ha^{-1}$ and average amount of silica supplied from irrigation water $42.5kg\;ha^{-1}$, ranging from $28.1kg\;ha^{-1}$ to $58.8kg\;ha^{-1}$. Silica amount percolated through the soil profile have uniform trend comparatively showing $62.9kg\;ha^{-1}$ in Control, $64.8kg\;ha^{-1}$ in NPK treatment and $62.9kg\;ha^{-1}$ in NPK+Si treatment. Silica uptaked by Rice plant was $335.6kg\;ha^{-1}$ in Control, $406.6kg\;ha^{-1}$ in NPK+Si treatment and $471.1kg\;ha^{-1}$ in NPK+Si treatment. The difference between an amount of Si input(from rainfall, irrigation water and silicate fertilizer) and an amount of Si output(percolated Si in soil, uptaked Si by rice plant) was $357.4kg\;ha^{-1}$ in control, $412.1kg\;ha^{-1}$ in NPK treatment and $238.2kg\;ha^{-1}$ in NPK+Si treatment. Results of our study imply that paddy soil is a potential pool as a source of Si supply during growing periods of rice plant.

• Korean Journal of Soil Science and Fertilizer
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• v.10 no.4
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• pp.245-256
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• 1978

The effects of different particle size distribution of fused phosphate on the changes of phosphorus content in soil and plant, growth and yield of paddy rice were investigated through pot and field experiments. The following results were obtained. 1. Negative correlation was found between unhulled rice yield and the composition of fused phosphate whose particle size was larger than 28 mesh, and 65 to 150 mesh, and highly significant correlation was found between unhulled rice yield and the composition of fused phosphate whose particle size was 28 to 48 mesh. But no significant correlation was found betweeen unhulled rice yield and the composition of fused phosphate whose particle size was 48 to 65 mesh. Thus the composition of 56% of 28 to 48 mesh particles and 44% of 48 to 65 mesh particles would give the best effect. 2. In the soil of the Jeonbug series rice plant in the plots treated with fine single textured fused phosphate showed poor early growth, i.e. poor tillering and short plant height. But at harvesting stage it showed rather increased number of tillers and higher plant height. Of the composite fused phosphate the more particles of 28 to 48 mesh it had, the better growth it showed. In the soil of the Yesan series rice plant in the treated plots showed much better tillering and higher plant height in contrast with that in the control plots. Of the single textured fused phosphate the finer particles showed better growth, while of the composite fused phosphate the more particles finer than 48 mesh it had, the poorer the tillering. 3. The content of available phosphorus in the soil tended to increase as the particles of both single textured and composite phosphate became finer. The soil phosphorus content decreased as the content of phosphorus absorbed by rice plant increased at each stage of growth, and the amount of soil phophorus decreased became larger as the the particles were finer. The amount of available phosphorus in the treated soils was larger in the soil of the Yesan series than in the soil of the Jeonbug series which was a long cultivated soil and contained relatively high phosphorus. 4. In the single textured fused phosphate the amount of phosphorus absorbed by rice plant tended to increase as the particles were finer, and great difference was found at heading stage, but at harvesting stage little difference was found for all the plots. In the field experiment in the soil of the Jeonbug series more phosphorus was absorbed by rice plant in the plots treated with the composite fused phosphate of higher content of 28 to 48 mesh particles. In the pot experiment the amount of phosphorus absorbed by rice plant was highest in the plots treated with the composite fused phosphate of 53.35% of particles larger than 48 mesh and 46.6% of particles smaller than 48 mesh. In the pot experiment in the Yesan series the amount of absorbed phophorus was highest in the plots treated with the fused phosphate of 47.75% of particles larger than 48 mesh and 50. 216% of particles smaller than 48 mesh. 5. A reverse relationship was found between the absorbed phosphorus and silica. In the pot experiment in the soils of both the Jeonbug and Yesan series the amount of phosphorus absorbed by rice plant increased as the particles were finer, while the amount of absorbed silica tended to decrease.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.22 no.2
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• pp.1-17
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• 1977

Nitrogen responses to yield and other agronomic characters were studied using four rice varieties, Tongil, Jinheung, Milyang 23, and Yushin, at six nitrogen levels, 0, 10, 15, 20, 25 and 30kg/10a, in a silt loam soil at the Crop Experiment Station, Suweon, Korea, in 1976. Grain yields of Milyang 23 and Tongil were much higher than those of Jinheung and Yushin at high nitrogen levels (15-30kg/10a). Optimum nitrogen levels of the rice varieties, Tongil, Milyng 23, Yushin, and Jinheung, estimated by intersecting straight line, were 22, 19, 19, and 12kg/10a, respectively. Morpshological characters, dry matter production before and after heading, and yield components were dicussed in relation to the nitrogen responsivenees of the rice varieties. In addition, relationships between yield, yield components, and other agronomic characters were discussed to obtain some informations for higher rice yield.