• 한국환경과학회지
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• 제30권3호
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• pp.195-206
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• 2021

Contaminated marine sediment is a secondary pollution source in the coastal areas, which can result in increased nutrients concentrations in the overlying water. We analyzed the nutrients release characteristics into overlying water from sediments and the interaction among benthic circulation of nitrogen, phosphorus, iron, and sulfur were investigated in a preset sediment/water column. Profiles of pH, ORP, sulfur, iron, nitrogen, phosphorus pools were determined in the sediment and three different layers of overlying water. Variety types of sulfur in the sediments plays a significant role on nutrients transfer into overlying water. Dissimilatory nitrate reduction and various sulfur species interaction are predominantly embodied by the enhancing effects of sulfide on nitrogen reduction. Contaminant sediment take on high organic matter, which is decomposed by bacteria, as a result promote bacterial sulfate reduction and generate sulfide in the sediment. The sulfur and iron interactions had also influence on phosphorus cycling and released from sediment into overlying water may ensue over the dissolution of ferric iron intercede by iron-reducing bacteria. The nutrients release rate was calculated followed by release rate equation. The results showed that the sediments released large-scale quantity of ammonium nitrogen and phosphate, which are main inner source of overlying water pollution. A mechanical migration of key nutrients such as ammonia and inorganic phosphate was depicted numerically with Fick's diffusion law, which showed a fair agreement to most of the experimental data.

• 한국유기농업학회지
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• 제4권2호
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• pp.97-136
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• 1995

Recendtly an organic agricultured in Korea is getting a public attention not only for minimizing NO3- contamination of groundwater but also for producing of quility of agricultural products. But still there is not Basic Standards for Organic Agriculture in Korea and Japan since they just believe organic agriculture is one kind of the environmental friendly sustainable agriculture as written in western literature. In the paper it was discussed the core skills and doctrine of IFOAM Basic Standards compare to Korean Organic Farming Method in oder to point out thed disadvantages of overuse of organic fertilizer, 50-150MT/㏊ in each cultivation, intensive monocropping in glass-house without any rotation & legume, and without any green manure. Most korean or-ganic farmer believe that the more they apply organic fertilizer, the better they pro-duce high quility of crops and they practise organic agriculture completely. It was also suggested the overuse of organic fertilizer cause the accumulation of NO3- in rhizosphere and subsequently it might lead to drinkwater pollution by nitrate leaching. In conclusion it is suggested that for successful establishment of organic agriculture, The Association of Korean Organic Agriculture, The Society of Korean Organic Agri-culture and the certification body should be developed the Basic Standards which is acceptable by IFOAM Basic Standards.

• Water Engineering Research
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• 제4권3호
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• pp.141-154
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• 2003

Nonpoint source pollutants from agriculture are identified as one of the main causes of water quality degradation in the United States. The Hydrological Simulation Program-Fortran (HSPF) was used to simulate runoff, nitrogen, and sediment loads from an urbanizing watershed; the Polecat Creek watershed located in Virginia. Model parameters related to hydrology and water quality were calibrated and validated using observed hydrologic and water quality data collected at the watershed outlet and at several sub-watershed outlets. A comparison of measured and simulated monthly runoff at the outlet of the watershed resulted in a correlation coefficient of 0.94 for the calibration period and 0.74 for the validation period. The annual observed and simulated sediment loads for the calibration period were 220.9 kg/ha and 201.5 kg/ha, respectively. The differences for annual nitrate nitrogen ($NO_3$) loads between the observed and simulated values at the outlet of the watershed were 5.1% and 42.1% for the calibration and validation periods, respectively. The corresponding values for total Kjeldahl nitrogen (TKN) were 60.9% and 40.7%, respectively. Based on the simulation results, the calibrated HSPF input parameters were considered to adequately represent the Polecat Creek watershed.

• 한국환경농학회지
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• 제19권5호
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• pp.370-374
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• 2000

At this study, the monitoring network of water quality was established in the agricultural watershed an area 14,960 ha of the central southwest of Korea. Loads of nitrogen and phosphorus by agricultural land use were quantified bases on total amounts of stream flow. The land were used as a lowland paddy, an upland and a forest about 12.14 % (1,815 ha), 5.17 % (773 ha) and 80.31 % (12,015 ha) of the area, respectively. For six months, from May 1 to October 31, 1999, the total precipitation was 970 mm and the total amount of stream flow was $80,281,000\;m^3$. In the load of agricultural non-point sources relevant to land use, total-N was 138,413 kg, then ammonia-N 13,362 kg, nitrate-N 124,629 kg, and total-P 157 kg. The loss of nutrient which from application of chemical fertilizer were 38.0% in nitrogen and 0.1% in phosphorus to input chemical fertilizer in the watershed.

• 한국대기환경학회지
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• 제31권6호
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• pp.508-519
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• 2015

The objective of this study was to quantitatively estimate $PM_{2.5}$ source contribution in Gyeongsan. Ambient $PM_{2.5}$ samples have been collected on zefluor, quartz and nylasorb filter by $PM_{2.5}$ samplers of cyclone method from September 2010 to December 2012. Collected samples were analyzed for determining 17 inorganic elements, 8 ions, and 8 carbon components after pretreatment. Based on these chemical information, the PMF model was applied to estimate the quantitative contribution of air pollution sources. The results of the PMF modeling showed that the sources were apportioned by biomass burning source (15.5%), secondary sulfate source (16.0%), industry source (10.4%), soil source (7.0%), gasoline source (9.1%), incinerator source (10.4%), diesel emission source (11.0%), and secondary nitrate source (20.6%), respectively. To analyze local source impacts from various wind directions, the CPF analysis were performed using source contribution results with the wind direction values measured at the site.

• 환경위생공학
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• 제4권1호
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• pp.7-15
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• 1989

According to the increase of population and development of industrialization air and water pollution problems are still keeping going to great nuisance to human activities. Specially man should drink 2l clean water to maintain our health every day, but we afraid of drink the city tap water because of the contaminants like heavy metals, bacteria trihalomethane, etc. In the analysis of the anions in potable water, we usually adapt the Standard methods for the Examination of Water and Wastewater. But this method is tedious and time consuming, so the Ion Chromatography method is now used in research of water quality. Author worked with Ion Chromatography in measuring the anions in drinking water by attaching conductivity dector to normal High Performance Liquid Chromatograph. Low-capacity ion-exchange coulmn and dilute eluents, 0.00M phthalic aic was used in this study. The concentration of chloride ion was 1.55 ppm$\~$3 8.81ppm, nitrate ion was 5.45 ppm$\~$18.27ppm, and sulfate ion was 19.64 ppm$\~$28.86 ppm. The phosphate ion was detected only in Apt. tap water as 167.99 ppm whose amount was supposed to be used as a water pipe cleaner.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2005년도 국제학술회의
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• pp.22-46
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• 2005

Spatial and timely information on crop and filed conditions is one of the most important basics for rational and efficient planning and management in agriculture. Remote sensing, GIS, and modeling are powerful tools for such applications. This paper presents an overview of the state of the art in remote sensing of crop and field conditions with some case studies. It is also shown that a synergistic linkage between process-based models and remote sensing signatures enables us to estimate the multiple crop/ecosystem variables at a dynamic mode. Remotely sensed information can greatly reduce the uncertainty of simulation models by compensating for insufficient availability of data or parameters. This synergistic approach allows the effective use of infrequent and multi-source remote sensing data for estimating important ecosystem variables such as biomass growth and ecosystem $CO_2$ flux. This paper also shows a geo-spatial information system that enables us to integrate, search, extract, process, transform, and calculate any part of the data based on ID#, attributes, and/or by river-basin boundary, administrative boundary, or boundaries of arbitrary shape/size all over Japan. A case study using the system demonstrates that the nitrogen load from fertilizer was closely related to nitrate concentration of groundwater. The combined use of remote sensing, GIS and modeling would have great potential for various agro-ecosystem applications.

• Journal of Applied Biological Chemistry
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• 제43권4호
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• pp.258-263
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• 2000

The study was carried out to investigate the nutrient losses at a paddy field located at the southwest of central Korea from May 1, 1997 to April 30, 1998. The studying area was 10 ha. The amounts of nutrients loaded by runoff water were measured as follows. The total-N was 1,031 and $61kg\;10ha^{-1}$ during the irrigation and non-irrigation periods, respectively. The total amount of N from both periods was $1,092kg\;10ha^{-1}\;yr^{-1}$. The total-P was 23 and $2kg\;10ha^{-1}$ during the irrigation and non-irrigation periods, respectively. The total amount of P from both periods was $25kg\;10ha^{-1}\;yr^{-1}$. For percolationloss, the losses of total-N, ammonia-N, nitrate-N, and total-P were 167,30,122, and $3kg\;10ha^{-1}$, respectively. The respective loss ratios of N and P by runoff water were 55.2 and 11.9%, while the loss ratios of N and P by percolationwere 8.4 and 1.4%.

• Journal of Applied Biological Chemistry
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• 제43권4호
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• pp.254-257
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• 2000

Water quality monitoring network was established at the agricultural watershed located at the Namdae-chon watershed of Seolchon-myon, Muju-gun, Chollabuk-do, Korea which is 22,560 ha in size. Based on total amount of stream flow loads of nitrogen and phosphorus from the agricultural watershed were estimated. About 4.48 (1,011 ha), 7.02 (1,585 ha), and 86.82% (19,609 ha) of the site were used for paddy fields, upland fields, and forests, respectively. During the period of 6 months from May 1 to October 31, 1999, the total amounts of precipitation and stream flow were 993.2 mm and $148,533,000m^3$ respectively. The loads of agricultural non-point sources accrued by land use were 83,526 kg, 24,508 kg, 49,705 kg, and 215 kg for total-N, ammonia-N, nitrate-N, and total-P, respectively. Results showed that 23.4 and 0.1 % of the applied nitrogen and phosphorus fertilizers, respectively, were estimated to load into the streams as agricultural non-point sources.

• 한국작물학회:학술대회논문집
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• 한국작물학회 1998년도 21세기 한반도 농업전망과 대책(한국작물학회.한국육종학회 공동주관 심포지움 회보)
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• pp.210-232
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• 1998

Tong-il, the high-yielding rice variety bred on early 1970, effected a turning point in modern rice production in Korea. As rice production reached the highest record yield in 1978 with HYV, Korea achieved self-sufficiency in domestic supply of rice (or the first time in (her own) history, HYV required high input of fertilizers and pesticides for proving its yielding ability and needed new techniques such as early nursery-planting to prevent chilling damage. But, farm economy did not follow the successful achievement of rice production because of increased farming cost and inflation.'Tong-il variety has been replaced by new high-yielding Japonica varieties from 1980 when record-low-temperature during summer months had persisted. Also, the cooked rice of Tong-il variety did not agree with the appetite of Korean people. Though the hectarage of Tong-il rice did reduce, farmers applied the same high-input cultural techniques for new Japonica cultivars as did for Tong-il variety. Heavy application of nitrogen fertilizer contaminated surface and ground water with nitrate ions while phosphorous fertilizer was blamed for algae pollution. Frequent spray of pesticide and herbicide reduced significantly the biotic population in paddy ecosystems including insects and soil microorganisms. The new technologies of the 21st century must be directed to produce safe food, to save natural resources, and to preserve a clean environment for human welfare. We need low-input sustainable farming techniques to provide high-yielding crops and to preserve a healthy ecosystem.