• Korean Journal of Environmental Biology
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• v.19 no.4
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• pp.232-238
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• 2001

Effects of atmospheric nitrogen deposition on terrestrial ecosystems were reviewed and discussed in this paper. The amount of nitrogen deposition has increased rapidly in Europe, North America and Korean due to industrialization, increase in fossil fuel combustion(automobiles in particular), and intensive agricultural activities. Nitrogen input through such deposition may enhance primary productivity at early stage, but it could cause nitrogen saturation and hence deterioration of forests of disturbance of systems in the long term. Mechanisms of the deterioration of forests by nitrogen deposition include nutrients imbalance, soil acidification, and immobilization of toxic ions. In addition, nitrogen deposition may impede the decomposition rates of soil organic matter, and induce eutrophication in aquatic ecosystems by enhanced leaching of nitrate. Finally, I propose several topics in relation to nitrogen deposition, which warrant further studies in Korea.

• Korean Journal of Environmental Agriculture
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• v.24 no.2
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• pp.132-138
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• 2005

Objective of this research was to evaluate the fate of nitrogen and phosphorous in hydroponic waste solution from the plastic film house cultivation applied to the upland soil by column leaching and field experiment. The pH and EC of leachate were decreased by the reaction with the upland soil in the column leaching experiment. The EC and concentrations of $H^+,\;K^+,\;and\;{NH_4}^+$ of leachate were decreased as the column length (soil depth) was increased. But these were increased as the amounts of the hydroponic waste solution were increased field experiment growing red pepper (Capsicum annum L.) to monitor the nutrients movement using ion exchange resin capsule demonstrated that the nutrient concentration of soil solution was increased in the orders of $PO_4-P. Nitrate concentration of resin capsule inserted into the soil was relatively higher than other nutrients $(NH_4-N\;and\;PO_4-P)$ at the 45 cm of soil depth. The overall results demonstrated that the hydroponic waste solution could be recycled as plant nutrients to enhance fertility of soils. But nitrate leaching was a major factor for safe use of the hydroponic waste solution in soil.

• Journal of the Korean Society of Groundwater Environment
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• v.6 no.3
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• pp.120-125
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• 1999

This study was carried out to enhance the efficiency of bioleaching of heavy metals. copper and zinc from the soil samples obtained from mine tailings in Cho-il Mine located in Dan-Yang, Choong-Buk. The effects of medium (9 K) composition on the leaching efficiency were investigated by changing concentrations of the dominant components. phosphorus, nitrogen source. and energy source which are the most important factors governing the growth and multiplication of microorganism. The results of the bioleaching test at different phosphorus concentrations of medium, 0 mM. 3.0 mM, and 6.0 mM showed that leaching efficiency for zinc and copper was 98.8% and 47.5% respectively at 0 mM and decreased at higher phosphorus concentration 6.0 mM. In the bioleaching test of zinc and copper at 0 mM, 45 mM, and 90 mM nitrogen concentrations, the Highest efficiency of 85% and 46.4% was obtained for zinc and cooper respectively at 45 mM and the lower efficiency observed for 90mM nitrogen addition. The zinc and copper leaching with variation of energy source dosage showed the highest removal efficiency, 93% for zinc in the absence of energy source and 46.4% for copper at 160mM energy source.

• Journal of The Korean Society of Grassland and Forage Science
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• v.23 no.3
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• pp.193-202
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• 2003

This study was conducted to investigate the effects of the type and application level of swine manure on herbage productivity, efficiency of nitrogen utilization and environmental pollution by the leaching of nitrogen compounds in mixed grassland. The field experiment was carried out on established grassland sward growing on silt clay loam soil. Main plots were the types of swine manure, such as swine manure fermented with sawdust(SMFWS), swine manure fermented without sawdust(SMF) and swine slurry(SS), and mineral fertilizer(Urea). Subplots were the application levels of swine manure, such as 100, 200 and 400 kgN/ha, The results obtained were summarized as follows; 1. Herbage productivity, nutritive value and nitrogen yields were the highest with mineral fertilizer and followed by swine slurry(SS), and the lowest with swine manure fermented with sawdust(SMFS). As compared with dry matter(DM) yield by application of mineral fertilizer(100%), the DM percents of SMFWS, SMFS and SS were 90.6, 80,9 and 76.8%, respectively. 2. Organic matter(OM) contents of the soil were increased by the applications of swine manure. OM contents were the high set with SMFS and the lowest with mineral fertilizer. 3. The amounts of nitrate leaching by types and application levels of swine manure were the highest in the end of Aug. and early of Sep. during the seasons and ranged from 10 to 25ppm.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2014.05a
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• pp.248-249
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• 2014

Photocatalytic cement is receiving attention due to its high oxidation power that oxidizes nitrogen oxides (NOx), thus contributing to clean atmospheric environment. However, there has not been a thorough investigation on durability of a parent material, cementitious material, as a result of photocatalytic reactions. In this study, durability of photocatalytic cementitious materials exposed to nitrogen dioxide (NO₂) gas was examined. Titanium dioxide (TiO₂) nanoparticles containing cement paste samples were exposed to cycles of NO₂ with UV light, followed by wetting and drying to simulate environmental condition. The surface of samples was characterized mechanically, chemically, and visually during the cycling. The results indicate that the photocatalytic efficiency decreased with continued NO₂ oxidation due to calcium carbonate formation. The pits found from SEM demonstrate that chemical deterioration have occurred, such as acid attack or leaching. In conclusion, the photocatalytic reactions and its product could alter cementitious materials chemically and mechanically which could further affect long-term durability.

• Asian Journal of Turfgrass Science
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• v.24 no.2
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• pp.145-148
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• 2010

Nitrogen (N) is one of the most important nutrients among 17 essential nutrients for maintaining turfgrass color and quality. The slow release fertilizers were initially developed to provide a more consistent release of nitrogen over a longer period and are often used to decrease leaching potential from sandy soils. The goal of this study is to determine if various slow release N sources affect the rate at which turfgrass establishes. Six nitrogen sources were evaluated; Nitroform (38-0-0), Nutralene (40-0-0), Organiform (30-0-0), Sulfur coated urea (SCU, 37-0-0), urea (46-0- 0), and Milorganite (6-0-0). The root zone media was seeded and sodded with 'Limousine' Kentucky bluegrass (Poa pratensis L.). Sodded pots produced 182 to 518 g more clipping dry weight than seeded pots. Among seeded pots, Milorganite produced greater amount of root dry weight than any other N sources. Because the period of turfgrass growth is different between sodded and seeded plots, there were differences on clipping yield and root growth. Overall, high N rate had turf color greater than acceptable color of 6 among seeded pots throughout the study. However, low N rate didn't produce acceptable turf color throughout the study. Based on the result of this tudy, ilorganite would be ecommended for new establishment of Kentucky bluegrass an urea with less clipping yield which can lead to reduce abor.

• Journal of the Korea Organic Resources Recycling Association
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• v.32 no.1
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• pp.49-59
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• 2024

Biodegradable coating urea plays an important role in reducing the non-pollutants in agroecosystems, maximizing the plant nutrient utilization efficiency and slow-releasing nitrogen. Herein, the objective of this study was to investigate the nitrogen-releasing patterns and greenhouse gas emissions on different biodegradable coating urea. The treatments consisted of the control as an application of chemical fertilizers, NBCF as the non-biodegradable coating urea, NB60, and MDS as biodegradable coating urea. As a result of this study, the maximum accumulated total nitrogen (TN) concentration in the NBCF was higher at 33% than one in the NB60 during the precipitation periods. Its leaching period in the NCBF was prolonged for day 10 compared to the NB60. TN and NO₃-N releasing patterns in the NBCF and NB60 were fitted well on linear types(R²≥0.991), but their control and MDS were fitted well on Sigmoid curves(R²≥0.994) with high releasing concentration in the MDS compared to the control during leaching periods. For the greenhouse gas emissions, CH₄ emissions in the NBCF, NB60, and MDS were increased at 0.38%, 11.36%, and 5.91%, and N₂O emissions were also increased at 50.5%, 32.4%, 58.8% as compared to the control, respectively. Therefore, application of biodegradable polymer coating urea might mitigate the non-point pollutants in agro-ecosystem.

• Magazine of the Korean Society of Agricultural Engineers
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• v.44 no.3
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• pp.146-156
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• 2002

The objective of this study was to develop a modified CREAMS model for paddy field conditions. The model simulates daily balance of water and nutrient from irrigated paddies using meteorological, irrigation, and agricultural management data. The model simulates daily evapotranspiration of paddy using Penman equation and determines daily flooding depth changes. Total nitrogen and phosphorus concentrations within flooding water, surface runoff, and leaching water from a paddy field also can be simulated. Parameters of the model were calibrated using observed data of the Agricultural Experiment Station of the Seoul National University in Suwon Korea. The model was applied for the irrigation period of paddy field in Gicheon area when 1,234 mm annual rainfall was occurred. The simulated losses of the total nitrogen and total phosphorous were 11.27 kg/ha and 0.98 kg/ha, respectively. There was a good agreement between observed and simulated data. It was found that CREAMS-PADDY model was capable of predicting runoff and nutrient losses from irrigated paddy fields.

• Journal of the Korea Institute of Military Science and Technology
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• v.6 no.2
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• pp.9-19
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• 2003

Nitrogen oxide gases which were produced by spontaneous reaction of nitrocellulose(NC) in the single base propellant accelerate the decomposition of propellant, and result in the reduction of shelf life. The amount of nitrogen oxide was reduced by the addition of 0.3wt% $CaCO_3$ to conventional stabilizer(DPA) and down of the solvent leaching temperature from $64^{\circ}C$ to $56^{\circ}C$, which extended the shelf life of the single base propellant as much as twice compare with commercial propellant. The perforation diameter increase of propellant from 0.64mm to 0.77mm could compensate for the drop of burning rate which was caused the addition of $CaCO_3$.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.2
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• pp.185-194
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• 1995

The prevention of excessive use of nitrogen fertilizer get an attention in Korea not only for minimizing $NO_3^-$ contamination of groundwater but also for establishment of environmental friendly sustainable agriculture. In order to find out the dynamics of $NO_3^-$ in barley rhizosphere and its suitability for nitrogen fertilization strategies and for environmental control, the accumulation of $NO_3^-$ in 3 layer, 0~30cm, 30~60cm, 60~90cm of soil profile has been detected in winter barley pro-duction system. It showed the recommended N fertilization rate for winter barley cause the $NO_3^-$ contamination of groundwater through $NO_3^-$ leaching during winter. The $NO_3^-$ content of 0~90cm soil depth have directly reflected the amount of basal N fertilization in the early spring, but not 0~30cm and 0~60cm soil depth. The contents of $NO_3^-$ measured to 0~30cm, 0~60cm soil depth were not significanly correlated with yield but the contents of $NO_3^-$ measured to 90cm soil depth was highly correlated with yield. Nitrogen fertilizer requirement could be estimated accurately by soil test and it provides field specific N rate recommendation for spring N application to winter barley. It was concluded that $N_{min}$ method could be applied to korean climatic and soil condition for optimal fertilizer application rate.