• Journal of Ecology and Environment
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• v.43 no.2
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• pp.129-160
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• 2019

Background: Characterizing and describing soils and land use and make a suggestion for sustainable utilization of land resources in the Ethiopian Rift valley flat plain areas of Lake Chamo Sub-Basin (CSB) are essential. Objectives: To (1) characterize soils of experimental area according to World Reference Base Legend and assess the nature and extent of salinity problems; (2) characterize land use systems and their role in soil properties; and (3) identify best land use practices used for both environmental management and improve agricultural productivity. Methods: Twelve randomly collected soil samples were prepared from the above land uses into 120 composites and analyzed. Results: Organic carbon (OC) and total nitrogen (TN) were varied along different land uses and depleted from the surface soils. The soil units include Chernozems (41.67%), Kastanozems (25%), Solonchaks (16.67%), and Cambisols (16.67%). The identified land uses are annual crops (AA), perennial crops (PA), and natural forest (NF). Generally, organic carbon, total nitrogen, percentage base saturation (PBS), exchangeable (potassium, calcium, and magnesium), available phosphorus (P₂O₅), manganese, copper, and iron contents were decreased in cultivated soils. Soil salinity problem was observed in annuals. Annuals have less nutrient content compared to perennials in irrigated agriculture while it is greater in annuals under rainfed. Clay, total nitrogen, available phosphorus, and available potassium (K₂O) contents were correlated positively and highly significantly with organic carbon and electrical conductivity. Conclusion: Management practices that improve soil quality should be integrated with leguminous crops when the land is used for annual crops production.

• Journal of Plant Biology
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• v.11 no.3
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• pp.1-7
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• 1968

Organic matter in rice-paddy soils exercises two antagonistic effects on the rice plant under water-logged conditions in growing season in the course of its decomposition: It liberates mineral nutrients and promotes soil fertility. On the other hand, however, it demands oxygen for its decay and therefore competes with rice roots for this element, when applied in large quantity of fresh status. For the practical end of rice culture, it is most desirable that these two effects should not contend with each other. To determine the proper content of organic materials to be applied, the influences of varied amounts of a homogeneous mixture of dried green manure, ranging from 0 to 20g/pot (1/20,000 tanbo), upon hte growth of rice was investigated in a sand culture. Labeled phosphorus fertilizer was also used in the form of KH232PO4 to evaluate the availability of this nutrient in the soil. Under the present experimental conditions, green mature seems to have influenced little on the growth of rice, except on number of grains produced and grains/straw ratio. Moreover, no sympton of growth inhibition is obsrvable even by the largest amount of its application. The available phosphorus, as estimated by A-value, appears to have increased, as the amount of organic materials applied increases. In view of the fact that pure sand instead of a paddy soil is used in this culture, the present results would not be directly applicable to practical rice farming. Besides, the estimated A-value is in need of further study, since it varies according to method of application, as suggested by Nishigki et. al. (1958).

• KOREAN JOURNAL OF CROP SCIENCE
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• v.46 no.1
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• pp.40-46
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• 2001

Ozone ($O_3$)-induced changes in chlorophyll content and specific activities of antioxidant enzymes, such as superoxide dismutase (SOD), ascorbate peroxidase (APX), guaiacol peroxidase (GPX), dehydroascorbate reductase (DHAR) and glutathione reductase (GR) were investigated in two rice cultivars (Oryza sativa L.) grown under variable nutrient treatments. For this study, two rice cultivars of Ilpumbyeo (IL) and Keumobyeo#l (KM), which were known as resistant and susceptible to $O_3$, respectively, were exposed to $O_3$at 0.15ppm for 30 days and investigated with 10 days interval. The available nutrient regimes were varied by doubling the supply of nitrogen (N), phosphorus (P) and potassium (K) Within a basic fertilizer status (N, P, K; 15, 12, 12kg/l0a$^{-1}$ ). In both cultivars and at all nutrient status, chlorophyll content in $O_3$-treated plants decreased with prolonged treatment period, although higher N, P and K supply with $O_3$ treatment alleviated the decrease in chlorophyll content. The activities of almost all enzymes investigated for this study were decreased during initial stages of $O_3$- exposure except GPX which maintained higher activity throughout the exposure period than the non-treated plant. However, the antioxidant enzymes in $O_3$-treated plants showed almost the same or higher activities on 30 days after $O_3$ - exposure. The most significant changes in activities were observed in GR of the $O_3$-treated leaves. With the prolonged treatment period, the activity of GR at 30 days was increased by 3-8 times compared to those in 10 days. Most of the investigated enzymes showed very similar tendency to $O_3$ treatment in all fertilizer status. There was no observed evidence for enhanced detoxification of $O_3$-derived activated oxygen species in plants grown under higher fertilizer status compared with that in plants grown under basic fertilizer status. The increase in the activities of SOD, APX and GR in rice leaves by relatively long-term treatment with $O_3$ at low concentration is considered to indicate that the plant became adapted to the $O_3$ stress and the protection system increased its capacity to scavenge toxic oxygen species. Our results in two rice cultivars indicated that there was little difference in the activities of antioxidant enzymes between IL and KM, which were known as resistant and susceptible cultivar to $O_3$

• Korean Journal of Agricultural Science
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• v.40 no.3
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• pp.177-182
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• 2013

A genus Camelina has been attracted as a promising oil crop, especially available in drought and marginal conditions. Due to more demands on arable land for bioenergy crops, price of agricultural products has been a challengeable issue. In that respect, development of Camelina crop with higher germination rate and germination energy can be a strategy to secure seedling establishment, nutrient uptake and long vegetative period. In order to be easily available in the field and laboratory conditions, Camelina seed needs to be optimized for its germination temperature. Germination temperature regime was in a range of 8 to $32^{\circ}C$ initially, and consecutively narrowed down to 8 to $20^{\circ}C$. Based on the temperature range, Camelina germinated greater than 96% at $8-16^{\circ}C$ in two weeks after sowing, but germination rate started to decrease at the higher than $24^{\circ}C$ and was significantly low at higher than $32^{\circ}C$. In terms of rapid time to reach the maximum germination rate and greater germination energy, temperature ranged from 12 to $16^{\circ}C$ was found to be desirable for Camelina germination. Although germinationa rate was greater at $16^{\circ}C$, lower temperature close to $12^{\circ}C$ would be favored for the field conditions where greater root growth leading to healthier seedlings and better nutrient or water availability is considerably demanded.

• Proceedings of the Korean Society of Applied Pharmacology
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• 2006.11a
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• pp.127-130
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• 2006

Coenzyme Q10(CoQ10) is a biological quinine compound that is widely found in living organisms including yeast, plants, and animals. CoQ10 has two major physiological activities:(a)mitochondrial electron-transport activity and (b )antioxidant activity. Various clinical applications are also available: Parkinson's disease, Heart disease, diabetes. Because of its various application filed, the market size of CoQ10 is continuously expanding all over the world. A Japanese company, Nisshin Pharma Inc. is the first industrial producer of CoQ10(1974). CoQ10 can be produced by fermentation and chemical synthesis. In several companies, these two methods are used for the production of CoQ10:chemical synthesis - Yungjin, Daewoong, Nishin Parma; fermentation - Kaneka, Kyowa, Yungjin, etc. Researchs in microbial production of CoQ10 have several steps: screening of producing microorganisms, strain development, fermentation process, purification process, scale-up process, plant production. Several strategies are available for the strain development : Random mutation and screening, directed metabolic engineering. For the optimization of fermentation process, various conditions (nutrient, aeration, temperature, culture type, etc.) are considered. Purification is one of the most important step because the quality of final products entirely depends on its purity. The production cost will be reduced and the quality of the CoQ10 will be impoved by continuous researches in strain development, fermentation process, purification process.

• 한국약용작물학회:학술대회논문집
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• 2006.11a
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• pp.127-130
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• 2006

Coenzyme Q10(CoQ10) is a biological quinine compound that is widely found in living organisms including yeast, plants, and animals. CoQ10 has two major physiological activities:(a)mitochondrial electron-transport activity and (b)antioxidant activity. Various clinical applications are also available : Parkinson's disease, Heart disease, diabetes. Because of its various application filed, the market size of CoQ 10 is continuously expanding all over the world. A Japanese company, Nisshin Pharma Inc. is the first industrial producer of CoQ10(1974). CoQ10 can be produced by fermentation and chemical synthesis. In several companies, these two methods are used for the production of CoQ10:chemical synthesis - Yungjin, Daewoong, Nishin Parma; fermentation - Kaneka, Kyowa, Yungjin, etc. Researchs in microbial production of CoQ10 have several steps: screening of producing microorganisms, strain development, fermentation process, purification process, scale-up process, plant production. Several strategies are available for the strain development : Random mutation and screening, directed metabolic engineering. For the optimization of fermentation process, various conditions (nutrient, aeration, temperature, culture type, etc.) are considered. Purification is one of the most important step because the quality of final products entirely depends on its purity. The production cost will be reduced and the quality of the CoQ10 will be impoved by continuous researches in strain development, fermentation process, purification process.

• Journal of the Korean Society of Tobacco Science
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• v.8 no.1
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• pp.69-78
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• 1986

This experiment was carried out to Investigate the environmental changes of rhizosphere, behavior of nutrient components in soul, and nutrients uptake and growth response of the tobacco plant in the condition that mulch as polyethylene film, had been removed on the ridge at the 50th day after transplanting in comparison with continuous mulching condition. The results obtained were as follows; 1. After rainfall, soil moisture content In the plow layer was greatly increased without mulch in comparison with that of the plot with mulch. As a result, leaf water potential of tobacco plant without mulch was higher than that with mulch. 2. Available nutrients such as $NH_4-N, \;NO_3-N$, and total salts in the plow layer of the plot without mulch tended to be Increased, and especially accumulated on the surface layer owing to the redistribution of soil water by rainfall during the latter growth stage after removing mulch. 3. Nutrients uptake by tobacco was much more enhanced in the plot without mulch and resulted in higher contents of total nitrogen, $NO_3-N, \;P_2O_5, \;and K_5O$ in the tobacco leaf Especially higher content of nitrogen caused the delay of maturity resulting In the increased of dry weight of top part of tobacco in the plot without mulch toned to be Increased in comparison with that in mulching condition. Content of total nitrogen, $NO_3-N$, and nicotine in flue-lured leaves was much higher in the plot without. mulch than in mulching condition, but lower content of reducing sugar in the plot without mulch resulted in lower quality of tobacco.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2005.10a
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• pp.496-501
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• 2005

SWAT2000 model directly estimate the loading of water, and nutrients from land areas in a watershed. it allows to add nutrient loading from the point sourece like a sewage treatment plant and it also has a GIS interface which can easily see the spatial relationship between subbasins. For better assessment of nutrients loading to KEUMGANG estuary, SWAT2000 model applied to KEUMGANG estuary watershed. Model calibration and verification was firstly poerformed at Gongju site duing the period $1999{\sim}2003$. $R^2$ value was 0.96 for streamflow, 0.94 for T-N load and 0.52 for T-P load. The accuracy of the model at Gongju site suggest that the SWAT2000 can be available to estimate streamflow, Nutrients loading to the KEUMGANG estuary.

• 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.

• Korean Journal of Soil Science and Fertilizer
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• v.42 no.1
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• pp.1-13
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• 2009

Understanding the net nutrient balance in a farming system is crucial in assessing the system's sustainability. We quantified N, P and K balances under vegetable organic farming in a Eutric Haplud and in West Java, Indonesia in five planting seasons from 2005 to 2007. The ten treatments and three replications, arranged in a completely randomized block design, included single or combined sources of organic fertilizers: barnyard manure, compos ts or green manures. The organic matter rates were adjusted every planting season depending on the previous crop responses. The result sshowed that the application of ${\geq}20$ t $ha^{-1}$ barnyard manure per crop resulted in positive balances of N, P, and K, except in the second crops of 2006 where potassium balance were -25 to -11 kg $ha^{-1}$ under the treatments involving cattle barnyard manure, because of low K content of these treatments and high K uptake by Chinese cabbage. Application of 20 to 25 t $ha^{-1}$ of plant residue or 5 t $ha^{-1}$ of Tithonia compost also resulted in a negative K balance. Soil available P increased significantly under ${\geq}25$ t $ha^{-1}$ barnyard manure and that under chicken manure had the highest available P. Accordingly, chicken barnyard manure gave the highest crop yield because of relatively higher N, P, and K contents. Plant residues gave the lowest yield due to the lowest nutrient content among all sources. Reducing the use of barnyard manure to 12.5 t $ha^{-1}$ and substituting it with Tithonia compost, Tithonia green manure or vegetable plant residue compost gave insignificantly different yield compared to the application of 25 t $ha^{-1}$ barnyard manure singly. In the long run, application of 25 t ha-1 cattle, goat, and horse manure or about 20 t $ha^{-1}$ chicken manure is recommendable for sustaining the fertility of this Andisol for vegetable production.