• Journal of The Korean Society of Grassland and Forage Science
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• v.9 no.3
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• pp.168-173
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• 1989

In this report two experiments were carried out. Vertical distribution of exchangeable potassium(K) of soil in the orchardgrass meadow was investigated‘ a and K leaching from soil was monitored under lysimeter condition throughout one year. The results obtained a are as follows; The difference in the exchangeable soil K content b between the soil layers was very small in K-zero plot of the orchard grass meadow, but it was significant in K¬h high plot (Experiment 1). T The volume of leached water from the Iysime ter was a about 471 liters/m2 during a year and the amount of leached water was influenced by the precipitation. D During the investigation the quantity of leached K was 2 22.3 g/$m^2$. About 40 % of the total K in a year leached out during the first two months, May and June, after the start of the experiment. On the other hand, leached K amounted to 13.2 g/$m^2$ (60 % of the total K leached) during the period of ten months from July, 1985 to A April, 1986, when forages were harvested from the soil o of the lysimeter (Experiment 2). From the above results, it was known that K leach¬i ing from grassland soil can be also occurred in consider¬a able amount when the growth stage of forage is not d developed or soil does not become solid on such a p period as immediately after grassland improvement or e establishment. However, unless the K leaching from soil s seems to be little under the condition of permanent g grassland ecosystem with higher grade of soil hardness a and possibly with compact density of forage plants.

• Korean Journal of Organic Agriculture
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• v.10 no.2
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• pp.95-109
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• 2002

This study focussed to find out the agronomic effect of high quality compost mixed with brown seaweed and to determine the optimum mixing rate of seaweed to compost for environmentally benign organic farming. The experiment was conducted in lysimeters at Experimental Farm of Dankook University with Chinese Cabbage(Bulam #1), and the crop growth such length and width of leaf, biomass of Chinese Cabbage were checked, the content of chlorophyll, sugar, vitamin C, nitrate in outer leaf and idler leaf was determined. It was observed that nitrate content was dramatically decreased in the plot of mixture with seaweed, while biomass and content of Vitamin C were increased steeply in the plot of mixture with seaweed. The best result was gained the 0.25% mixture of brown seaweed with compost.

• Journal of the Korean Geosynthetics Society
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• v.10 no.2
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• pp.67-72
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• 2011

CMDS (Coal Mine Drainage Sludge) is mainly generated from acid mine drainage during physicochemical treatment or electrical purification. CMDS is well worth considering on recycling possibilities in various areas. This research applies the liner and cover materials using waste disposal landfill generally to treat acid mine drainage sludge. In this Part I of the two parts paper, physico-chemical characteristics of CMDS, bentonite and cement to prepare the liner have been identified using XRD, XRF, FESEM. In addition, combining their physicochemical characteristics, the optimum mixing ratio has been determined to be 1: 0.5: 0.3 for CMDS: bentonite: cement by the batch tests. Initial permeability of CMDS was $7.10{\times}10^{-7}cm/s$. Through the leaching test, it was confirmed that its mixture was environmentally safe. In the Part 2, a large-scale Lysimeter was used to simulate the effects of the layer on the freeze/thaw for evaluation on field applicability and stability.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 1998.06a
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• pp.69-73
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• 1998

경기도 퇴촌에 위치한 경희대학교 연습림내의 경사도와 수종을 달리하는 3개의 서로 다른 임반에서 등고선을 따라 지표면의 토층분화를 조사하였고 이에 따른 수분침투특성을 조사하였다. 3개의 임반은 낙엽송, 잣나무 및 굴참나무의 천연활엽수로 구성되었고 이에 구성 수종에 따라 지표면에 퇴적되는 O, A, B층의 깊이를 달리한다. 토층분화 길이는 3개 임반 모두 경사도가 낮은 하부사면에서 양호하게 발달하였으며 경사도가 높은 산사면이나 수간우가 많은 일부 지역에서는 유거수에 의해 유기물이나 표층토가 유실되어 바로 암반층 또는 풍화층이 나타나는 경향을 보이고 있다. 그러나 잣나무 임반의 경우 밀식 수간에 의해 유기물퇴적층과 A층의 발달이 다른 낙엽송이나 굴참나무 임반보다 토층 발달 깊이가 약 2배 이상으로 깊게 발달되었다. 그리고 조사된 임반의 하부사면의 경우 A층의 발달이 약 35cm부터 약 60cm에 이르고 있으나 토성을 구성하는 요소 중 직경 2mm 이상의 자갈에 토양입자들이 전체 토양의 40%정도를 차지하고 있다. 이러한 토층분화 특성을 달리하는 임반에서의 수분 이동특성은 퇴적된 유기물의 두께가 깊으면 깊을수록 수분침투율은 낮아지는 반면 포면 유거수량은 증가하는 경향을 보여주고 있다. 그리고 지표면, 유기물 퇴적층 아래, 지표면으로부터 30cm 아래에 설치된 Lysimeter를 이용하여 조사된 침출수의 분포는 전체를 100으로 환산시 지표면은 약 55%, 유기물퇴적층 아래는 30%, 그라고 30cm의 위치에서는 나머지 15%정도의 침출수가 포집되었다. 따라서 본 실험의 결과를 살펴보았을 때 지표 층에 존재하는 유기물이 전체 수분이동에 영향을 미치는 것으로 조사되었다.양 실험 결과, 서식지에서 조사된 결과인 잎과 줄기에서 Pb$\alpha$ 추정시에는 SeaWiFS 위성과 관련된 global algorithms 중에서 490nm와 555nm의 복합밴드를 포함하는 OC2 알고리즘(ocean color chlorophyll 2 algorithm)을 사용하는 것이 OC2 series 및 OC4 알고리즘보다 좋은 추정 값을 도출할 수 있을 것으로 기대된다.환경에서는 5일에서 7월에 주로 이 충체의 유충이 발육되고 전파되는 것으로 추측되었다.러 가지 방법들을 적극 적용하여 금후 검토해볼 필요가 있을 것이다.잡은 전혀 삭과가 형성되지 않았다. 이 결과는 종간 교잡종을 자방친으로 하고 그 자방친의 화분친을 사용할 때만 교잡이 이루어지고 있음을 나타내고 있다. 따라서 여교잡을 통한 종간잡종 품종육성 활용방안을 금후 적극 확대 검토해야 할 것이다하였다.함을 보이고 있다.X> , ZnCl$_{3}$$^{-}$같은

• KOREAN JOURNAL OF CROP SCIENCE
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• v.43 no.4
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• pp.264-268
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• 1998

The experiment was conducted to clarify irrigation requirement and percolation rate in rice paddy. The four rice cultural system of no-tin, till, transplanting, and direct seeding condition were treated in the lysimeter filled with sandy loam soil. The amounts of irrigation and soil percolation were measured daily, and irrigation requirement was estimated. The daily percolation was 19.5 l/$\textrm{m}^2$ in no-till direct seeding on flooded paddy surface, 17.4 l/$\textrm{m}^2$ in both of till-direct seeding on flooded surface and no-till transplanting, and 15.2 l/$\textrm{m}^2$ in transplanting plot. This is equivalent to 19.5, 17.4, and 15.2 mm per day, respectively. Highest irrigation requirement was 3,770 l/$\textrm{m}^2$ in no-till direct seeding plots. Others were 3,249, 2,577, and 2,321 l/$\textrm{m}^2$ in till-direct seeding, no-till transplanting and transplanting plot, respectively. The estimated irrigation requirement of no-till transplanting, till-direct seeding and no-till direct seeding was increased by 11, 37, and 59% compared to till-transplanting plot. Percolation rate of no-till transplanting, till direct seeding and no-till direct seeding was increased by 12%, 40%, and 66%, respectively compared to the till-transplanting plot. The percolation rate in paddy soil was increased greatly after reproductive stage of rice.

• Proceedings of the Korea Water Resources Association Conference
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• 2007.05a
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• pp.1423-1426
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• 2007

The goal of this research is to develop and apply the integrational model for the pan evaporation and the alfalfa reference evapotranspiration in Republic of Korea. Since the observed data of the alfalfa reference evapotranspiration using lysimeter have not been measured for a long time in Republic of Korea, PM method is used to assume and estimate the observed alfalfa reference evapotranspiration. The integrational model consists of staochastics and neural networks processes respectively. The stochastics process is applied to extend for the short-term monthly pan evaporation and alfalfa reference evapotranspiration. The extended data of the monthly pan evaporation and alfalfa reference evapotranspiration is used to evaluate for the training performance. For the neural networks process, the generalized regression neural networks model(GRNNM) is applied to evaluate for the testing performance using the observed data respectively. From this research, we evaluate the impact of the limited climatical variables on the accuracy of the integrational operation of stochastics and neural networks processes. We should, furthermore, construct the credible data of the pan evaporation and the alfalfa reference evapotranspiration, and suggest the reference data for irrigation and drainage networks system in Republic of Korea.

• Journal of Environmental Impact Assessment
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• v.8 no.1
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• pp.41-49
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• 1999

This study was carried out to estimate the runoff loading characteristics of the non-point source pollutions in the Youngsan river basins by the method of land-use types and rainfall. The lysimeter test, rainfall and stream flowmeter measurement were performed to develop the pollutant loading unit discharged from the non-point sources. As the non-point sources, the unit pollutant discharge rates were different from the land-use types such as paddy field, upland, forest, housing site and others. The pollutant loading units classified by land-use types in the Youngsan river basins are as follows: The total BOD loading rate is 15.3 ton/day and the housing site is discharged 50.6%, the total T-N loading rate is 6.0 ton/day and the paddy field and upland is discharged 77.6%, and the total T-P loading rate is 0.39 ton/day and the paddy field and upland is discharged 81.2%. The pollutant loadings by rainfall in the Youngsan river basins are about 7,425 ton/year of BOD, 324 ton/year of T-N and 118 ton/year of T-P, respectively.

• Korean Journal of Soil Science and Fertilizer
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• v.46 no.5
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• pp.313-321
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• 2013

The Average daily PET (Potential evapotranspiration), evaluated based on the last 30 years meteorological data and the lysimeter experiment carried out by RDA during 11 years, of 9 regions in Korea for the tomato cultivated in greenhouse, was $3.41mm\;day^{-1}$. Two kinds of water saving irrigation standard (WSIS), deficit irrigation standard (DIS) and partial root-zone drying irrigation standard (PRDIS) that include the irrigation interval and the amount of irrigation water according to the region, soil texture and growing stage, were established. According to the DIS and PRDIS, the cultivator can save water up to 29.2% and 53.7%, respectively, for tomato cultivation in greenhouse compared to the full irrigation standard (FIS) which established in 1999. WSIS can be used easily by the cultivator without complicate procedures such as soil sampling and measurement of soil water status by expensive sensors. But the cultivator should care about irrigation method such as PRDI (partial root-zone drying irrigation) without yield decrease.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.2
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• pp.306-311
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• 2012

Water management is the most important and difficult problems in red pepper cultivation.The water requirement of red pepper is different according to the area as well as climate condition, growth stage and soil texture. Also, the measurement of evapo-transpiration (PET) and crop coefficient (Kc) is very difficult especially in field cultivation. The average PET during 30 years of southern region of korea for the red pepper cultivation was a $2.75mm\;day^{-1}$. The water saving irrigation manual with irrigation interval and amount of irrigation according to growing season and soil texture, are developed based on the lysimeter experiments carried out by the RDA for 11 years about potential evapo-transpiration, crop coefficient for the 17 southern region of korea. The water saving irrigation manual can be used with easy to the farmer without soil sampling and any kinds of sensors measuring soil water status.

• Magazine of the Korean Society of Agricultural Engineers
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• v.39 no.4
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• pp.114-121
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• 1997

In order to provide basic information for the estimation of evapotranspiration in the ponded direct seeding paddy field, both field lysimeter experiment and model prediction were performed to estimate daily ET. Various methods were used to predict daily reference crop ET and crop coefficients. Measure4 mean daily ET during the 1995 growing season varied from 5.9 to 6.1 mm depending on the species, while it varied from 5.1 to 5.5 mm in 1996. Model predicted mean daily ET during the 1995 growing season varied from 3.9 to 4.9 mm depending on the prediction model, while it varied from 3.5 to 4.7 mm in 1996. The smaller ET values both measured and predicted in 1996 were caused by the low values of temperature, sunshine hours, and solar radiation. Crop coefficients varied from 1.20 to 1.50 in 1995 depending on the prediction model, while it varied from 1.10 to 1.47 in 1996. Comparison of the seven reference crop ET prediction methods used in this study shows that the Penman-Monteith method and the FAO-Radiation method gave the lowest ET while the corrected Penman method and the Hargreaves method gave the largest ET. Since crop coefficients vary to a large extent based on the prediction methods, reference crop ET prediction method should be carefully selected in irrigation planning.