• Magazine of the Korean Society of Agricultural Engineers
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• v.43 no.6
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• pp.154-162
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• 2001

This study was performed to examine the rice growth and nutrient change in paddy soil with reclaimed sewage irrigation. Total nitrogen and total phosphorus in the experimental system were analyzed before and after rice culture. The experiment lasted three consecutive years, and this paper presents results of the last year. Additional supply of nutrients to the rice culture by reclaimed sewage irrigation was significant and it increased the yield. Nutrient uptake by rice plant increased with more nutrient supplied, however. there was limit in plant uptake. Nutrient accumulation occurred in the soil and it was more apparent for the phosphorus where most of the remaining quantity was accumulated while substantial amount of nitrogen was lost during the growing season. This study suggested that additional nutrient supply by reclaimed sewage irrigation might be a supplemental benefit to the rice culture, and it can help the fertilization management. However, long term effects of continual reclaimed sewage irrigation should be assessed carefully including nutrient mass balance in the paddy rice culture system.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.27 no.2
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• pp.43-53
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• 2024

This study attempted to elucidate the ecological niches and influencing environmental factors of Quercus variabilis and Quercus acutissima, which are representative deciduous broad-leaved trees in Korean forests, taxonomically close and genetically similar, under climate change conditions. Under climate change conditions induced by increased CO₂ and temperature, soil moisture and nutrient environments were manipulated in four gradients. At the end of the growing, plants were harvested to measure growth responses, calculate ecological niches, and compare them with those of the control. Eperimental plants were grown for 180 days in a glass greenhouse designed with four gradients each for soil moisture and nutrient environments under climate change conditions induced by increased CO₂ and temperature. After harvesting, growth responses of leaf traits were measured, ecological niches were calculated, and these were compared with those of the control groups. Furthermore, the responses of the two species' populations were interpreted using principal component analysis(PCA) based on leaf trait measurements. As a result, under climate change conditions, the ecological niche breadth for moisture environment was broader for Quercus variabilis than Quercus acutissima, whereas for the nutrient environment, Quercus acutissima exhibited a broader niche breadth than Quercus variabilis. And the rate of change in ecological niche breadth due to climate change decreased for Quercus variabilis in both moisture and nutrient environments, while for Quercus acutissima, it increased in the moisture environment but decreased in the nutrient environment. Additionally, in terms of group responses, both Quercus variabilis and Quercus acutissima expanded their ecological niches under climate change conditions in both soil moisture and nutrient conditions, with Quercus acutissima exhibiting a broader niche than Quercus variabilis under nutrient conditions. These results indicate that the changes in leaf morphological characteristics and the responses of individuals reflecting them vary not only under climate change conditions but also depending on environmental factors.

• Korean Journal of Microbiology
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• v.29 no.5
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• pp.329-338
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• 1991

From July 1985 to December 1986, 28 variables of phycal-chemical factors, bacteria and heterotrophic activity were investigated 17 times at 3 stations in the estuary of Naktong River and the influences of environmental factors to bacterial population and heterotrophic activity were analyzed through multiple regression. The results of multiple regression were as follows. At station 1, total bacteria and heterotrophic bacteria(Z-25) could explain 57% of the variation of maximum uptake velocity for glucose and 54% of turnover time for glucose was explained by total coliform bacteria and MBOD, Sixty four percent of the variation of Kt+SN was accounted for salinity, MBOD-N and inorganic phosphate. Turnover rate for acetate was also accounted for the change of MBOD-P by 56%. At station 2 maximum uptake velocity for glucose depends on MBOD-N by 81%; turnover time on bacteria by 50%; Kt+Sn on avilable nutrient by 61%. More than 50% of maximum uptake velocity and turnover time for glucose were influenced by bacteria and that of Kt+Sn by the change of nutrient in the surface water of station 3. In the bottom water of station 3, the change of maximumuptake velocity, turnover time and Kt+Sn for glucose was controlled by total bacteria and available nutrient, bacteria, the change of nutrient salts respectively. On the whole, more than 50% of maximum uptake velocity and turnover time for glucose could be due to the change in the number of bacetria and the value of Kt+Sn was affected by the change of nutrient salts. Turnover rate for acetate was controlled by available phosphate at station 1 and by bacteria at station 2 and 3, which showed a distinct difference between the environmental factors which govern the rate of glucose and acetate uptake in the Naktong esturine ecosystem. And bacterial communities were controlled by available nutrients at station 1, by nutrient salts and salinity at station 2 and in the surface water of station 3 and by salinity in the bottom water of station 3.

• Applied Biological Chemistry
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• v.29 no.1
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• pp.78-82
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• 1986

Panax ginseng seedlings were grown in vermiculite with nutrient solution different in nitrogen, phosphorus ana potassium level. Ginsenoside contents of root were investigated by high performance liquid chromatogram. Elimination or increase of one of N.P.K. increased or decreased total saponin content. Nitrogen was most effective (15.5% for-N to 8.9% for 3N) and potassium least. Similar trend was shown in each ginsenoside. According to coefficient of variation in one nutrient treatment or among all nutrient treatments ginsenoside Re was most insensitive to nutrient change and also other environmental factors and Rd most sensitive. Diol content (PD) was more variable than triol (PT) and variation of PT/PD was about half of them. Variation of ginsenoside content by nutrient change had no relation with the ginsenoside content. Similarity of ginsenoside pattern slightly decreased with the difference of saponin content by nutrient change. Root weight was significantly small only in tap water plot.

• Journal of Nutrition and Health
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• v.33 no.8
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• pp.901-908
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• 2000

The study was carried out to assess whether the nutritional management program by dietician at child center can affect nutritional status of children at child care center. The diet intakes were measured by mother\`s record at home and by direct weighing at child care centers, and the hight and weight of children were measured before and after nutritional management program for 3months to see the effects. The energy intakes were significantly increased 56.29 Kcal after program, and protein 3.61g, lipid 3.12 g, calcium 49.71mg, iron 0.39 mg, vitamin B$_1$ 0.084 mg, vitamin B$_2$ 0.116 mg, and vitamin C 10.10 mg, respectively, except vitamin A and niacin. the significant changes of nutrient intakes were more at higher age group compared to at the lower age group, and more at girls compared to boys, Although the significant increase fo nutrient intakes at child care center, most nutrient intakes at home were not significantly changed, except energy, lipid, iron, vitamin A. The changes at changes of fat and calcium intakes for 3 months were positively correlated to the change of Z-score for weight, and the change of A-score for weight was positively correlated to changes of Z-score for height. The results showed that the nutritional management program for 3 month at child care center can increase nutrient intakes significantly and the incresed nutrient intakes can enhance children\`s growth. (Korean J Nutrition 33(8) : 901-908, 2000)

• Korean Journal of Soil Science and Fertilizer
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• v.48 no.6
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• pp.671-676
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• 2015

Control of surface runoff from upland soil is essential to reduce nonpoint source pollution. The use of non-woven fabric as a soil cover can be helpful to control surface runoff. The field experiment was conducted to evaluate the furrow cover effects of black non-woven fabric on the nutrient discharge from upland soil used for red pepper cultivation. The experimental plots consisted of chemical fertilizer (CF), cow manure compost (CMC), and pig manure compost (PMC) treatment. Each nutrient material treatment plot has control (no furrow cover (NFC)) and black non-woven fabric cover treatment, respectively. The amount of nutrient application was chemical fertilizer of $190-112-149(N-P_2O_5-K_2O)kgha^{-1}$, cow manure compost of $29.5tonha^{-1}$, and pig manure compost of $7.9tonha^{-1}$ as recommended amount after soil test for red pepper cultivation. Compared to control (NFC), furrow cover treatment with black non-woven fabric reduced the amount of T-N discharge by 50% at CF treatment, 36.9% at CMC treatment, and 44.8% at PMC treatment. Furrow cover treatment with black non-woven fabric reduced the amount of T-P discharge by 37.1% at CF treatment, 49.9% at CMC treatment, and 63.4% at PMC treatment compared to control (NFC). The production of red pepper did not show significant difference. There was no weed occurring in furrow cover treatment plots with black non-woven fabric. Results from this study showed that the furrow cover with black non-woven fabric could play a significant role in reduce nutrient discharge from upland soil used for red pepper cultivation.

• Journal of Korean Society on Water Environment
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• v.26 no.1
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• pp.19-27
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• 2010

Submerged plants whose most of vegetative mass are below the water surface can have great effects on wetland biogeochemistry and water purification through their photosynthesis and nutrient uptake processes. In this study, change of dissolved oxygen concentration and pH as well as nutrient removal capacity of the submerged plant dominant wetland were investigated using wetland mesocosm experiments. Obvious periodic DO and pH fluctuation was observed due to photosynthetic activities of the submerged plants. It implies that the submerged plants can provide periodic or sequential changes of oxic and anoxic conditions that affect nitrification and denitrification processes and contribute permanent nitrogen removal in the wetland system. The pH changes in the wetland mesocosm suggested that submerged plant could also play an important role as a temporary $CO_2$ storage. Higher nutrient removal efficiency was observed in the submerged plant dominant wetland mesocosm. The removal efficiencies under experimental conditions were 38.89, 84.70, 91.21, 70.76, 75.30% of TN, DIN, $NH_4-N$, TP, $PO_4-P$ in the wetland mesocosm, while those were 26.11, 57.34, 63.87, 28.19, 55.15% in the control treatment, respectively.

• Korean Journal of Community Nutrition
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• v.16 no.1
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• pp.14-22
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• 2011

This study was designed to compare the incidence and severity of premenstrual syndrome (PMS) between normal (N = 85) and overweight or obese (N = 28) college female students and investigated correlation between PMS, nutrient intake, hematological index and psychological index (depression, anxiety, stress). Each subject was asked a Menstrual Discomfort Questionnaire (MDQ) for PMS by 5 Likert scale. The PMS scores of women in the normal weight subjects ranked in order of severity were water retention (2.71), followed by behavioral change (2.58), negative affect (2.46), pain (2.31), autonomic reaction (2.27), decreased concentration (2.16). The symptoms of 'pain' and 'behavioral change' of overweight or obese subject were significantly higher than those of normal subject (p < 0.05). And total cholesterol concentration of overweight or obese subjects was significantly higher than in normal subject (p < 0.05). There was a significant positive correlation (p < 0.05) between the symptoms of 'negative effect' and BMI. And the triglyceride concentration was positively related with 'water retention (p < 0.01)'. The symptoms of 'decreased concentration' were negatively correlated with calcium (p < 0.01) and vitamin B6 intake (p < 0.05). The depression score were positively related with symptoms of 'behavioral change (p < 0.05)', 'negative affect' (p < 0.01), and the anxiety score was positively correlated with 'behavioral change (p < 0.05)' and 'decreased concentration (p < 0.05)'. The stress score was positively correlated with 'decreased concentration (p < 0.01)', 'behavioral change (p < 0.05)' and 'negative affect (p < 0.05)'. This suggests that PMS represents the clinical manifestation of a calcium, vitamin $B_6$ deficiency and psychological disorder. Therefore we concluded that nutrient supplementation, depression and stress management may help to relieve PMS symptoms.

• Journal of Biosystems Engineering
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• v.15 no.4
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• pp.328-338
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• 1990

The objective of this study was to develop automatic systems of nutrient solution management for optimal nutrient solution environment and labor saving in water culture which enables factory crop production. In this study, an automatic control system and its driving program are developed to prepare, supply, and recover nutrient solution and to keep the optimal solution concentration level using microcomputers. Based on this study, the following conclusions are obtained: 1. The concentration measured by the system using oscillating circuit designed and built in this study, gave good agreements with the actual nutrient solution. 2. In water culture, the period of 12 hours for measuring concentration, pH, and temperature of the nutrient solution was optimum. Addition of control solution due to the decrease of the nutrient solution concentration is required in every 3 to 5 days. 3. It is estimated that the period of the whole solution change is 15 days, however, further research is needed to assure it. In addition, this period must be shortened in the future. 4. Both the hardware and software of the developed optimal nutrient solution control system in the water culture are working very well, however, it is necessary to develop a more economical one-chip micro controller to substitute for the microcomputer.

• Korean Journal of Agricultural Science
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• v.50 no.4
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• pp.967-976
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• 2023

Biochar is emerging as a promising substance for achieving carbon neutrality and climate change mitigation. It can absorb several nutrients via ion bonding on its surface functional groups, resulting in slow dissociation of the bonds. Biochar, like organic fertilizers, contributes to sustainable nutrient management. The purpose of this study was to investigate the effects of nutrient-coated biochar amendments on leafy vegetables production and soil fertility. The nutrient-coated biochar was produced by soaking rice husk biochar in a nutrient solution containing nitrogen (N), phosphorus, and potassium for 24 hours. Nutrient-coated biochar and organic fertilizers were applied to soil at a rate of 120 kg·N·ha^-1. The growth components of the leafy vegetables showed that nutrient-coated biochar led to the highest fresh weight (FW) of both lettuce and kale (i.e., 146.67 and 93.54 g·plant^-1 FW, respectively). As a result, nutrient-coated biochar amendments led to superior yield compared to the control treatment and organic fertilization. The elemental composition of leafy vegetables revealed that soil amended with nutrient-coated biochar resulted in higher nutrient contents, which was attributed to the high nutrient contents supplied by the rice husk biochar. Soil amendment with nutrient-coated biochar positively enhanced the soil fertility compared to amendment with organic fertilizer. Therefore, nutrient-coated biochar is a promising substance for enhancing agronomic performance of leafy vegetables and improving soil fertility.