• Korean Journal of Environmental Agriculture
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• v.26 no.2
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• pp.107-115
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• 2007

Objective of this study was to assess the efficient rice cultivation practice to mitigate the non-point source pollutants loading to the adjacent watershed. Cultivation practices consisted of machine transplanting, direct seeding on dry paddy, and no tillage in which no fertilizer and pesticide were applied to paddy field. Water in drainage canal was used as irrigation source during the entire rice growing season. Loading of the non-point source pollutants to the adjacent small stream was mitigated by all treatments. Rice yield, total biomass (rice + weeds), and uptake T-N, $P_2O_5$, and $K_2O$ were higher in machine transplanting practice than those in direct seeding and no tillage practices. However, the purification effects of non-point source pollutants were followed in orders of no tillage > direct seeding > machine transplanting due to quantity of irrigation water. The annual purification quantity of T-N, T-P, and K by rice cultivations ranged from 46 to 369 kg $ha^{-1}$, 4.1 to 16.4 kg $ha^{-1}$, and 55 to 238 kg $ha^{-1}$, respectively, during the entire rice growing season. Results revealed that no tillage practice of rice cultivation was the best management option in reducing the loading of the non-point source pollutants from the drainage canal into stream.

• 한국환경농학회:학술대회논문집
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• 2009.07a
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• pp.93-115
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• 2009

There are growing public concerns over crop and food safeties due to the elevated levels of heavy metals grown in contaminated soil. Heavy metals are classified as the chemical harmful risks for crop and food safety. With implementation of GAP, crop safety is controlled by many regulatory options for soil, irrigation water and fertilizers. Any attempt to retard the metal uptake by crops may be the best protocol to secure crop and food safety. This article reviews the management strategies for heavy metals in view of crop safety in Korea and demonstrates results from the field experiments to retard metal translocation from soil to crops by using chemical amendments and soil layer management methods. Major source of soil pollution by heavy metals has been related with mining activities. Risk assessment revealed that rice consumption and groundwater ingestion in the abandoned mining areas were the major exposure pathways for metals to human and the heavy metal showed the toxic effects on human health. Chemical amendments such as lime and slag retarded Cd uptake by rice (Oryza sativa L.) by increasing soil pH, lowering the phytoavailable Cd concentration in soil solution, immobilizing Cd in soil and converting the available Cd fractions into non-available fractions. The soil layer management methods decreased the Cd uptake by 76% and Pb by 60%. Either reversing the surface layer with subsurface layer or immobilization of metals with layer mixing with lime was considered to be the practical option for the in-situ remediation of the contaminated paddy soils. Combination of chemical soil amendments and layer management methods was efficient to retard the metal bioavailability and thus to secure crop safety for heavy metals. This protocol seems to be cheap, relatively easy to practice and practical in the agricultural fields. However, a long term monitoring work should be followed to verify the efficiency of this protocol.

• Journal of Korean Society for Geospatial Information Science
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• v.16 no.1
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• pp.13-21
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• 2008

This study conducted water quality projection of year 2010 in Miho stream of the Geum river basin by using GIS. Pollutant load data of corresponding tributary of the Miho stream is estimated based on the pollutant load of TMDL zone to simulate water quality of the Miho stream for BOD, TN, and TP. The pollutant load of the urban area such as Bochung and Musim stream basin is relatively high and the wastewater treatment plant of Chunju city directly affects the entire water quality of the target area. As a result, simulation result reveals that water treatment facility needs more refined treatment process for efficient water quality management. Also, to meet the target water quality of the Miho stream water quality simulation estimates the additional dilution flow by increasing irrigation water supplied from the Daechung dam through the Musim stream.

• Journal of Ecology and Environment
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• v.30 no.3
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• pp.271-276
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• 2007

A simple and efficient protocol was developed for culturing Cu-tolerant and Cu-accumulating plants via pre-adaptation to Cu during plant tissue culture. We induced multiple shoots from begonia (Begonia evansiana Andr.) leaf explants on MS medium supplemented with naphtaieneacetic acid and benzyladenine. After 3 months, small plantlets were transferred to MS medium supplemented with $100{\mu}M\;CuCl_2$ for pre-adaptation to Cu and cultured for 5 months. Then, these plantlets were individually planted in pots containing artificial soil. An additional 500 mg of Cu dissolved in 1/4 strength MS solution was applied to each pot during irrigation over the course of 2 months. We planted pre-adapted and control begonias in soil from the II-Kwang Mine, an abandoned Cu mine in Pusan, Korea, to examine their ability to tolerate and accumulate Cu for phytore-mediation. Pre-adapted begonias accumulated $1,200{\mu}g$ Cu/g dry root tissue over the course of 45 days. On the other hand, non-Cu-adapted controls accumulated only $85{\mu}g$ Cu/g dry root tissue. To enhance Cu extraction, chelating agents, ethylenediamine tetraacetic acid (EDTA)-dipotassiun and pyridine-2,6-dicarboxylic acid (PDA), were applied. While the chelating agents did not enhance accumulation of Cu in the roots of control begonias, EDTA application increased the level of Cu in the roots of pre-adapted begonias twofold (to $2,500{\mu}g$ Cu/g dry root tissue). Because pre-adapted begonias accumulated a large amount of Cu, mainly in their roots, they could be used for phytostabilization of Cu-contaminated soils. In addition, as a flowering plant, begonias can be used to create aesthetically pleasing remediation sites.

• Spatial Information Research
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• v.3 no.1
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• pp.39-46
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• 1995

Rural water resources systems may be largely constituted by two parts. One is rural water supply systems such as reservoirs, wells, pumping stations. The other is rural water demand systems which include municipal water, irrigation water, industrial water, livestocks water, inland fisheries water and envir¬onmental water in rural areas. planning to develop rural water resources systems is a very hard task because of their complicated factors and the large number of spatial data to investigate and manipulate. A Geographic Information SystemCGIS) will be a powerful and efficient tool to handle the spatial data and to plan the land use. All data can be efficiently maintained and easily updated. This paper refers to the construction of a GIS for planning rural water resources systems applied to Kokseong County, Cheonnam Province, Republic of Korea. The Geographic Informa¬tion was constituted by 4 layers of base map and 11 layers of thematic map.

• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.273-273
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• 2015

전통적으로 우리나라의 농업용수 공급시스템은 개수로 방식이 주로 사용되어 왔으나, 최근에는 지형의 영향을 덜 받으면서 안정적으로 용수공급이 가능한 관수로 시스템으로서의 전환이 늘어나는 추세이다. 특히 서남해안간척사업, 새만금 등 대단위 농업단지 조성이 늘어나면서 경제적인 수리시설의 설치와 유지관리에 대한 관심이 증대되고 있다. 우리나라의 관수로화 사업은 1980년대 중반부터 농업용 관수로 사업이 시행되어 왔다. 그러나 현재 운영 중인 농업용관수로 지구에서는 특별한 물관리에 대한 규정이 없고, 사용자의 급수요청에 따른 불규칙한 용수관리운영이 이루어지고 있다. 또한, 농업용수의 무분별한 사용과 운영관리방안의 부재로 인해 많은 양의 농업용수가 낭비되고 있다. 기존 개거에 비하여 관수로의 경우 통수량이 증가되어 관개에 소요되는 시간은 단축 되었으나, 급수소요시간의 변화에 따른 적절한 적용을 하지 못하여 지나치게 많은 양이 공급되고 있다. 이러한 문제점으로 인하여 발생되는 수자원의 낭비를 막기 위해 농업용 관수로의 운영계획이 필요하지만, 현재 농업용 관수로 운영기준은 사실상 없는 실정이다. 본 연구에서는 현재 운영되고 있는 호남지역의 해남지구를 대상지구로 선정하여 EPANET(US Environmental Protection Agency)모형을 이용하여 농업용 관수로시스템의 관망해석을 실시하고자 한다. EPANET모형을 통하여 대상지구의 급수방식을 분석하고, 용수량의 운영현황 자료를 비교 검토하여 계획수요량과 공급량을 비교하여 관수로시스템에서의 농업용수 공급능력을 검토하고자 한다.

• Journal of Soil and Groundwater Environment
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• v.22 no.4
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• pp.1-8
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• 2017

Efficient groundwater management requires accurate information about the water volume used. The pumped volume of groundwater can be indirectly estimated using empirical formulae based on electric power consumption. The purpose of this study is to test the accuracy of this indirect method. The Haean basin in Gangwon is located in a rural area, where majority of the groundwater extracted is used for irrigation. The pumped volume of groundwater indirectly estimated from electricity usage using these empirical formulae was compared with the actual pumped volume determined by conducting experiments on April 29 and May 19, 2017. The field survey collected data on electricity usage, pumped volume, and groundwater levels. Based on this measured data, correlations were calculated between electricity usage and pumping volume, as well as groundwater level and pumping rate. The results show that electricity usage and pumped volume measured for both wells (YHE1 and YHE2) are highly correlated (r=0.99, p<0.001). However, for YHE1, notably, the correlation between the groundwater level and pumping rate was not significant, and only some correlations were identified for these variables for the YHE2 test well. The average error with respect to the estimation of the actual pumped volume from the existing formula (1) and formulae (2) and (3) are +399% and -88%, respectively. To reduce these errors, these formulae need to consider other factors affecting the pumped volume.

• Korean Journal of Soil Science and Fertilizer
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• v.8 no.4
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• pp.199-217
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• 1975

For the establishment of efficient method of potassium topdressing on rice the optimum time and amount were investigated and discussed on the basis of available data from nutriophysiological studies, soil characteristics and fertilizer trials in fields. The followings were pointed out. 1. According to yield rice plants require more potassium around heading under water culture. 2. Potassium involves in harvest index, filled grain ratio, grain weight and number of spikelets per panicle. 3. Potassium is lost after heading in most fields in spite of highest requirement during this period. 4. The higher $K_2O/N$ ratio in straw at harvest is, the higher the yield. 5. Relatively low efficiency of potassium fertilizer under the field condition may be due to improper application method rather than natural supply from soil and irrigation water. 6. Appropriate topdressing time appears at in effective tillering stage for the prevention of nitrogen excess and at 15 to 20 days after transplanting, ear formation stage and 5 days after heading for the prevention of soil reduction damage. Two times of topdressing for clayey soil and three times for sandy soil seems reasonable in practice together with nitrogen topdressing, 7. The reasonable ratio basal to topdressing of potassium fertlizer seems to be 2/3 and $N/K_2O$ ratio of fertilization for ear formation stage appeared also as 2/3.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.272-272
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• 2022

Water and phosphorus (P) fertilizer are two of the most critical inputs in rice cultivation. Under climate change scenarios and urbanization, irrigation and fertilizer are becoming limiting factors often leading to significant decrease in yield whenever supplied scarcely. It has been shown that the Pup1 QTL confers tolerance to P starvation and improved early-stage root vigor in indica rice grown in the tropics. However, whether the QTL works in japonica rice genetic background grown in temperate regions remains to be elucidated. Here, we have introgressed the Pup1 QTL into three temperate rice varieties MS11, TR22183, and Dasan using marker-assisted backcrossing and next generation sequencing. The selected lines all harbored the full Pup1 QTL with recurrent parent genome recovery rates ranging from 66.5% to 99.8%. Evaluation of the introgression rice lines grown in South Korea under low inputs of P and water revealed early vegetative growth advantage relative to that of the recurrent parents. Under rainfed condition, Pup1 introgression lines had yield advantage ranging from 7.2 to 19.9% and 24 to 26% in P non-supplied soil and P-supplied soil, respectively compared to that of the recurrent parents suggesting that Pup1 confers enhanced yield under low P and water inputs in temperate rice genetic background grown in temperate climate. In terms of early vegetative growth, temperate Pup1 introgression lines showed a similar trend on the extent to which Pup1 promotes yield advantage in temperate rice in comparison with indica control Pup1 introgression line IR64-Pup1.

• Journal of Ecology and Environment
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• v.48 no.1
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• pp.110-119
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• 2024

Background: The Mae Kha Canal is one of Chiang Mai's most important waterways. It supports local agriculture, irrigation, and transportation as well as provides stormwater drainage to prevent floods. Due to the unregulated rapid urbanization of the city and lack of efficient waste and wastewater management systems over the past few decades, the canal has become heavily polluted. This study aimed to evaluate the water quality of Mae Kha canal through assessment of the physico-chemical water quality and coliform bacteria. Moreover, benthic macroinvertebrates were samples and assessed using the Biological Monitoring Working Party (BMWP^Thai) and Average Score Per Taxon (ASPT^Thai) as biological indices. Results: The physico-chemical showed low dissolved oxygen levels, high levels of ammonia and phosphates, and elevated levels of biochemical oxygen demand, indicating that the water quality had significantly deteriorated. The canal was found to be heavily polluted, with most sites falling into the polluted to very heavily polluted. Coliform bacteria analysis revealed alarmingly high levels of total coliform bacteria and fecal coliform bacteria in the canal. The BMWP^Thai and ASPT^Thai scores indicated poor to very poor water quality. Conclusions: The physico-chemical and coliform bacteria indicated that the water quality of the Mae Kha canal had significantly deteriorated. The biological indices also indicated the poor to very poor water quality. This study underscores the urgent need for comprehensive remediation efforts, emphasizing strategic planning, investment, and community engagement to revive the canal's ecological health and water quality.