• 한국지하수토양환경학회지:지하수토양환경
• /
• 제20권3호
• /
• pp.65-73
• /
• 2015

The hydrofluoric acid (HF) leakage accident occurred on September 2012 in Gumi, Korea affected the surrounding soils and plants. In this study, we investigated fluoride migration in Gumi area through geochemical properties of soil-liquid phase (pore water F and water-soluble F). The concentrations of porewater F and water-soluble F were obtained from N.D (Not detected) to 9.79 mg/L and from 0.001 to 21.4 mg/L, respectively. F in pore water seemed to be affected by artificial and natural origin, and PHREEQC results implied that fluorite is F control factor. F concentrations of soil and soil-liquid phase did not exceed concern level of regulatory criteria and showed similar trends compared by previous studies. Therefore, F contents remained in the soil and soil-liquid phase were considered to be not affected by HF leakage accident.

• 한국토양비료학회지
• /
• 제46권1호
• /
• pp.32-39
• /
• 2013

The relationship between relative water contents of lettuce leaves and biochemical activities in lettuce was examined in this study to explore an adaptation response of lettuce to water stress from soils. Soil water contents and relative water contents of leaves were positively related to show $R^2$=0.8728. Hydrogen peroxide contents of leaves rapidly increased with reduction of soil water content, whereas soluble protein contents and dry matters rapidly decreased. And chlorophyll a and b contents of leaves decreased with increase in carotenoid content. Furthermore, the activities of ascorbate peroxidase (APX), monodehydroascorbate reductase (MDHAR), and dehydroascorbate reductase (DHAR) increased dramatically, and mRNA transcript levels of APX, MDHAR and DHAR also increased. Relationship of relative water content of lettuce leaves to hydrogen peroxide, to ascorbate peroxidase activity, to dehydroascorbate reductase activity, and to monodehydroascorbate reductase activity was shown to be positively correlated. It is highly plausible from this study that these enzyme activities could be developed as an indicator of water states in soils.

• 한국토양비료학회지
• /
• 제46권6호
• /
• pp.409-416
• /
• 2013

Millet and sorghum are major dryland cereal crops, however their growth and productivity is limited by soil water stress with varying intensity. The major objective of this study was to evaluate water stress of millet and sorghum yield under drainage classes of poorly drained soil and to test the effect of the installed pipe drainage in poorly drained paddy soil to minimize crop stress. The research was carried out in poorly drained paddy fields located at alluvial slopping area resulting in non-uniform water content distribution by the inflow of ground water from the upper part of the field. Stress Day Index (SDI) was determined from a stress day factor (SD) and a crop susceptibility factor (CS). SD is a degree of measurement by calculating the daily sum of excess water in the profile above 30cm soil depth ($SEW_{30}$). CS depends on a given excess water on crop stage. The results showed that sum of excess water day ($SWD_{30}$) used to represent the moisture stress index was lower on somewhat poorly drained soil compared with poorly drained soil on 117 days. CS values for sorghum were 57% on $3^{rd}$ leaf stage, 44% on $5^{th}$ leaf stage, 37% on panicle initiation, 23% on boot stage, and 16% on soft dough stage. For proso millet CS values were 84% on $3^{rd}$ leaf stage, 70% on $5^{th}$ leaf Stage, 65% on panicle initiation, 53% on boot stage, and 28% on soft dough stage. And for foxtail millet the values were 73% on $3^{rd}$ leaf stage, 61% on $5^{th}$ leaf stage, 50% on panicle initiation, 29% on boot stage, and 15% on soft dough stage. SDI of sorghum and millet was more susceptible to excess soil water during panicle initation stage more poorly drained soil than somewhat poorly drained soil. Grain yield was reduced especially in proso millet and Foxtail millet compared to Sorghum.

• 한국농림기상학회지
• /
• 제18권1호
• /
• pp.30-41
• /
• 2016

본 연구에서는 강우-유출모델링에서 선행습윤상태를 파악하기 위해 자주 사용되는 여러 선행강우지수를 활용하여, 실제 측정된 토양수분자료들로부터 평가된 토양 저류량과의 비교 분석하고자 하였다. 나아가, 선행강우지수와 측정된 토양저류의 변화특성을 이용하여, 이전연구들에 비해 보다 명확한 관계를 이끌어낼 수 있었다. 이 관계를 바탕으로 약 2년여동안의 강우자료만을 통해 일 토양저류량을 모의하였으며, 측정된 일 토양저류량 값과 비교를 하였다. 모의된 토양저류량은 실제 측정된 토양저류량의 변화를 대체적으로 잘 묘사하고 있지만, 식생의 계절적인 변화와 영향과 관련한 수문학적 과정들의 변화로 인해 다소 차이가 있었다. 비록 본 연구결과가 경험 식으로부터 도출되었지만, 미 계측유역에서의 선행습윤상태를 파악하는 데 유용할 것으로 판단된다.

• The Korean Journal of Ecology
• /
• 제5권2_3호
• /
• pp.123-131
• /
• 1982

The growth and the resistance of Amorpha fructicosa L. under water control was experimented in frames out of doors. The plant grew in a wagner's pot under water control. The soil moisture content was controlled at 5%, 10%, 15% and 20%. The growth of leaf, stem and root in the groups of 5% and 10% soil moisture content were different from values in the groups of 15% and 20%. The T/R ratio in the groups of 5% and 10% soil moisture content were different from the ratio in the groups of 15% and 20% soil moisture content. The T/R ratio of former was lower than the latter, but the C/F ratio of the former was higher than the latter. RGR and NAR of Amorpha fructicosa decreased in 5% and 10% soil moisture content but increased in 15% and 20% soil moisture content during growing period. The maximum values of RGR and NAR were respectively 0.089 and 0.080 at 20% soil moisture content. The highest value of LAR was 1.560 at 5% soil moisture content. RGR and NAR were comparatively affected by soil moisture content.

• 한국물환경학회지
• /
• 제22권4호
• /
• pp.619-625
• /
• 2006

Amount of soil loss is important information for the proper water quality management, In this research, annual average soil loss of the Geum River basin was estimated using RUSLE (Revised Universal Soil Loss Equation) and GIS (Geographic Information System). Input data were manipulated using ArcGIS ver. 8.3. From crop field which constitute 8.2% of the Geum River Basin, annual average soil loss was estimated as 53.6 ton/ha/year. From the rice paddy field which constitutes 20% of the Geum River Basin, soil loss was estimated as 33.5 ton/ha/year, In comparison, forestry area which constitutes 61.8% of the basin discharged 2.8 ton/ha/year, It could be known from this research that appropriate measures should be implemented to prevent excessive soil loss from the agricultural areas.

• 한국환경생태학회지
• /
• 제20권4호
• /
• pp.425-435
• /
• 2006

본 연구에서는 암석비탈면 등에서 주요 녹화식물로 많이 이용되고 있는 등나무를 대상으로 황폐지 토양조건에서 인위적으로 함수율을 조절하여 등나무의 내건성과 토양수분조건에 따른 생장특성을 시험하였는 바, 그 결과를 요약하면 다음과 같다. 1. 등나무 묘목은 토양함수율 5% 수준에서 수분 스트레스를 받아 고사하였고, 토양함수율 10% 수준에서는 전 생장기간 동안 생장률에 큰 변화가 없었다. 따라서 본 시험토양에서 토양함수율 5% 수준이 등나무 모목의 위조함수율이며, 토양함수율 10% 수준이 생장에 대한 임계토양수분 범위로서, 등나무는 내건성이 있는 것으로 확인되었다. 2. 묘목의 신장생장, 직경생장, 엽생장, 총 건물생산량 등의 주요 생장요소들을 기준으로 분석한 결과등나무 묘목의 생장은 전반적으로 토양함수율이 높을수록 양호하였으며, 이들 각 생장요소들(Y)은 토양함수율(W)에 대해 Y=a+bW+cW2의 곡선형을 나타내었다. 3. 토양함수율 20 % 이상에서는 생장기간이 길어질수록 묘목 생장량이 뚜렷이 증가하였으며, 각 토양함수율 수준에서 묘목 생장량(Y)은 생장기간(D)에 대해 Y=a+bD+cD2의 곡선형을 나타내었다. 4. 토양함수율 20% 이상에서는 동일한 수분조건에서 근류균 접종구는 대조구에 비해 총 건물생산량을 기준으로 하면 평균 30%의 생장촉진효과가 있었다. 5. 근류균은 토양함수율이 높을수록 접종이 용이하고 근류의 형성량도 많았다.

• 한국토양비료학회지
• /
• 제32권4호
• /
• pp.357-364
• /
• 1999

본 연구는 사과나무의 수분이용, 신초 생장 및 작물계수에 미치는 토양수분영역과 잔디 피복의 영향을 조사하였다. 이를 위해 비가림 시설하에 3년생 사과 '후지'/M. 26 (Malus domestica Borkh.)을 재식한 3반복 double pot-lysimeter 실험을 수행하였다: (A) 토양 매트릭 포텐셜 -50 kPa의 점적관수 (IR50), (B) 토양 매트릭 포텐셜 -80 kPa의 점적관수 (IR80), 및 (C) 지하 0.45 m의 정체 자유수면 (WT45), 각 처리에 나지와 잔디 피복의 두 가지 지표상태를 두었다. 평균 월별 수분이용은 IR50 처리에서 IR80 처리보다 컸으며, WT45 처리에서 가장 컸다. 점적관수 처리 사과나무의 월별 작물계수는 시간의 1차 함수로 증가하였으나 ($r^2=0.953^{***}$, 잔디 피복 $r^2=0.862^{***}$, 나지), WT45 처리 사과나무의 작물계수는 변동하였다. 신초생장은 잔디 피복 IR50 처리에서 가장 컸으며, 나지 WT45 처리에서 가장 작았다. 토양의 Kjeldahl 질소는 처리에 관계없이 동일하였으나 8월 10일 측정한 엽중 Kjeldahl 질소는 WT45 처리보다 점적관수 처리에서 높았다.

• Journal of Forest and Environmental Science
• /
• 제28권4호
• /
• pp.232-241
• /
• 2012

We investigated the relationship between vegetation type and soil carbon dynamics in even-aged alder (Alnus hirsuta) and Korean pine (Pinus koraiensis) plantations in central Korea. Both forests were located on the same soil parent material and occupied similar topographic positions. Soil $CO_2$ efflux in the two plantations was determined using a dynamic chamber method accompanied by measurements of soil moisture content and temperature. Mean soil temperature was similar in the two plantations, but mean soil water content was significantly higher in the alder plantation than in the pine plantation. In both plantations, seasonal patterns in soil $CO_2$ efflux exhibited pronounced variation that corresponded to soil temperature. Soil water content did not affect the seasonal variation in soil $CO_2$ efflux. However, in summer, when soil temperature was above $17^{\circ}C$, soil $CO_2$ efflux increased linearly with soil water content in the alder plantation. Estimated $Q_{10}$ was 3.3 for the alder plantation and 2.7 for the pine plantation. Mean soil respiration during the measurement period in the alder plantation was 0.43 g $CO_2\;m^{-2}\;h^{-1}$, which was 1.3 times higher than in the pine plantation (0.33 g $CO_2\;m^{-2}\;h^{-1}$). Higher soil $CO_2$ efflux in the alder plantation might be related to nitrogen availability, particularly the concentration of $NO_3{^-}$, which was measured using the ion-exchange resin bag method.

• 한국지반공학회논문집
• /
• 제33권4호
• /
• pp.25-34
• /
• 2017

불포화상태 지반의 흡수력과 응력변화를 반영한 토사사면의 전체 안정성 평가에서 매우 중요한 상태평가 입력변수로 함수특성곡선이 활용되고 있다. 함수특성의 경로의존성은 일반적으로 건조와 습윤과정으로 이력현상을 내포하는데 현장계측결과는 주로 실내실험의 습윤과정에 가깝게 나타난다. 본 연구에서는 이를 비정상류 해석에 적용하여 해석과 현장 계측된 결과들을 비교 검토하였다. 또한 심도가 증가할수록 강우의 영향이 작고 습윤과정을 적용해 산정된 값에 근접하였다. 따라서 불포화 토사사면 해석 시에 경로의존 함수특성곡선을 적용하여 안정성을 판단하는 것이 보다 합리적인 결과로 판단된다.