• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2005년도 총회 및 춘계학술발표회
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• pp.122-126
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• 2005

Groundwater monitoring wells (about 70 wells) were extensively installed in 28 sites surrounding Lake Texoma, located on the border of Oklahoma and Texas, to assess the impact of geochemical stressors to shallow groundwater quality. The monitoring wells were classified into three groups (residential area, agricultural area, and oil field area) depending on their land uses. During a two-year period from 1999 to 2001 the monitoring wells were sampled every three months on a seasonal basis. Water quality assay consisted of 25 parameters including field parameters, nutrients, major ions, and trace elements. Occurrence and level of inorganics in groundwater samples were related to the land-use and temporal change.

• 한국토양비료학회지
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• 제48권6호
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• pp.610-617
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• 2015

The impact of 1 pound of nitrous oxide ($N_2O$) on warming the atmosphere is almost 310 times that of 1 pound of carbon dioxide. Agricultural soil management is the largest source of $N_2O$ emissions, accounting for about 73% of total $N_2O$ emissions. This study was conducted to evaluate the nitrous oxide emission in the cultivation of soybean during the first year of No-tillage (NT) and Conventional-tillage (CT) practices, under the various conditions such as different kinds of fertilizers, soil temperature, and moisture level. In the experiment, we set CT and NT treatments into 4 different groups - control treatments (no fertilization), green manure treatments, chemical fertilizer treatments and organic manure treatments. In the case of chemical fertilizer treatments, $N_2O$ emission of NT treatment was 7.78 to 22.59% lower than CT treatment. In organic manure treatment, $N_2O$ emission of NT treatment was 6.62% higher than CT treatment in August. But In July and September, $N_2O$ emission of NT treatment was 9.50% 28.38% lower than CT treatment, respectively. Soil temperature was correlated with $N_2O$ emission positively. In the future, continued long-term research on influence of various environmental factors on the generation of $N_2O$ and the economic value of no-till farming is required.

• 한국지하수토양환경학회지:지하수토양환경
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• 제18권5호
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• pp.26-38
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• 2013

In this study, priority for groundwater contamination management was assessed based on regional vulnerability in Goyang-si area, Gyonggi-do, Korea using analytic hierarchy process (AHP) and geographic information system (GIS). We proposed a concept for regional vulnerability to groundwater contamination with using socio-environmental vulnerability factors, which can be classified into three properties including regional hydrogeological property, contamination property, and groundwater use property. This concept is applied to Goyang-si area. For AHP analysis, an expertise-targeted survey was conducted. Based on the survey, a total of 10 factors (criteria) and corresponding weights for regional vulnerability assessment were determined. The result shows that regional contamination property is the most weighted factor among the three property groups (hydrogeological property: contamination property: groundwater use property = 0.3: 0.4: 0.3). Then, database layers for those factors were constructed, and regional vulnerability to groundwater contamination was assessed by weighted superposition using GIS. Results show that estimated regional vulnerability score is ranged from 22.7 to 94.5. Central and western areas of Goyang-si which have groundwater tables at shallow depths and are mainly occupied by industrial and residential areas are estimated to be relatively highly vulnerable to groundwater contamination. Based on assessed regional vulnerability, we classified areas into 4 categories. Category 1 areas, which are ranked at the top 25% of vulnerability score, take about 2.8% area in Goyang-si and give a high priority for groundwater contamination management. The results can provide useful information when the groundwater management authority decide which areas should be inspected with a high priority for efficient contamination management.

• 한국산림과학회지
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• 제35권1호
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• pp.1-8
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• 1977

산림토양(山林土壤)의 비옥도(肥沃度)를 수치분석방법(數値分析方法)으로 평가(評價)하였다. 본연구(本硏究)에서 35개(個) 토양통(土壤統)의 화학분석치(化學分析値)를 인용(引用)하였다. (표(表) 2) 조림수종(造林樹種)이 만족할 생장(生長)을 할 수 있는 최소양료함량(最小養料含量)의 평가(評價)는 표(表) 1과 같이 Wild씨(氏)의 기준치(基準値)에 준(準)했다. 시비요구수준(施肥要求水準)은 식(式)1을 사용(使用)하여 표(表)5와 같이 평가(評價)되었다. 토양통간(土壤統間)의 화학분석(化學成分)의 유사성(類似性)은 식(式)2를 이용(利用)하여 5개특성군(個特性群)으로 구분(區分)하였다. 1. 표토(表土)의 일반적(一般的)인 화학성질(化學性質) 공시통양토중(公試土壤統中) 약(約) 40%가 각각(各各) 유기물함량(有機物含量) 2%이하(以下), 인산함량(燐酸含量) 10ppm이하(以下), 치환성석회(置換性石灰)와 고토함량(苦土含量)이 1.25m.e/l00g 과 0.5m.e/100g 이하(以下)인 토양(土壤)이다. 치환성가리(置換性加里) 함량(含量)의 부족현상(不足現象)은 나타나지 않고 있다. CEC함량(含量)이 10m.e/100g 이하(以下)가 전체(全體)의 2/3가 되며 pH5.5이하(以下)인 강산성토양(强酸性土壤)이 전체(全體)의 4/5가 된다. 2. 각토양통(各土壤統)의 시비요구(施肥要求) 여부는 CEC, OM, MgO의 화학분석치(化學分析値)를 상대치화(相對値化)하여 공식(公式)1을 적용 간접적(間接的)으로 평가(評價)하였다. 35개(個) 토양통중(土壤統中) 8개통(個統)의 화학성분량(化學成分量)이 부족(不足)하여 시비요구(施肥要求)가 높은 것으로 생각되며 13개통(個統)의 화학성분(化學成分)으로 보아 시비(施肥)의 필요성(必要性)이 낮은 것으로 보여진다. 3. 토양통간(土壤統間) 화학성분(化學成分)의 유사성(類似性)을 비교(比較)한 결과(結果) 비옥도(肥沃度)는 다음과 같이 5개군(個群)으로 구분(區分)함이 적합(適合)한 것으로 생각된다. 1. CEC가 낮은 토양(土壤) 1-1 유기물함량(有機物含量)이 2%이라(以下)의 토양(土壤) 1-2 유기물함량(有機物含量)이 4%이라(以下)의 토양(土壤) 2. CEC와 유기물함량(有機物含量)이 높은 토양(土壤) 2-1 고토함량(苦土含量)이 낮은 토양(土壤) 2-2 고토함량(苦土含量)이 높은 토양(土壤) 3. 석회(石灰)와 고토함량(苦土含量) 높은 석회암질토양(石灰岩質土壤).

• 한국잡초학회지
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• 제17권1호
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• pp.124-134
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• 1997

As control of plant diseases, insects and weeds were heavily relied on pesticides, residues of pesticides in environment and food supply were recently focused by environmentalists and consumer groups. The reduction of pesticide use was implemented in Sweden, Denmark, Netherland, England, and United States. Therefore, it is very important to discuss environmentally sound systems of weed management including cultural, mechanical, and integrated weed control. Mechanical methods using tillage, cultivation, mulching, burning, mowing, solarization, and UHF are used as one of most effective environmentally sound weed management systems. Cultural practices favoring the crops are excellent weed management measures. Correct seedbed preparation for the soil and cultural system, and use competitive cultivars contribute to weed management. Increasing crop density by higher seeding rate or by narrowing row width and careful attention to optimum fertility to produce vigorous crop plants increase competitiveness of crops against weeds. Crop rotation breaks life cycles of weeds by alternating the crop it must associate with. Herbicides are efficient and profitable to control weeds, but must be part of a total weed management program with use of minimum rate. The best weed management will be an integrated approach including two or more methods to manage weed problems.

• 한국토양비료학회지
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• 제42권2호
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• pp.103-109
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• 2009

강원도 남부(영월)와 충북 제천, 단양 등지에 널리 분포하는 석회암에서 유래된 토양은 점토 및 철분함량이 많은 식질계 토양이며 pH와 염기포화도(base saturation)가 높은 붉은색 토양이다. 이 토양은 식양질과 식질 등의 세립(細粒)질로만 구성이 되어 있고 자갈이 있는 토양으로 분류된다. 따라서, 토양의 침투 및 투수속도가 우리나라 토양의 주 모재인 화강암이나 화강편마암 유래 토양과는 다른 양상을 보인다. 본 연구는 세립질 특성을 보이는 석회암 유래 토양의 지표면에서의 침투속도와 토양층위별 투수속도를 측정해 복잡하게 세분되어 있는 토양의 종류를 수문학적인 목적에 따라 단순화하기 위해 만든 수문학적 토양 유형으로 분류하고자 하였다. 실험을 위해 이용된 토양은 과림, 모산, 장성, 마지, 안미, 평안의 6개 토양통이었고 장력 침투계(disc tension infiltrometer)와 투수속도 측정계(Guelph permeameter)로 침투 및 투수속도를 측정했다. 현장 측정 이후 토양층위별로 시료를 채취하여 실험실조건에서 입도분포, 유기물함량을 측정했다. 토양통별 침투 및 투수속도를 측정한 결과는 유기물 층이 존재하는 과림통은 공극이 많고 토층 내에 나무 및 식물뿌리가 존재해 전체적으로 침투 및 투수속도가 빠른 특성을 보여 수문유형을 A로 분류하였다. 모산통은 토층 내에 자갈함량이 아주 높고 투수속도가 다른 토양에 비해 월등히 빠른 특성을 나타냈으나 50 cm이내에서 암반층이 존재하는 관계로 수문유형이 B/D로 분류되었다. 토층이 깊지 않은 장성통은 토층 내에 나무 및 식물뿌리가 많고 암석노출지가 존재해 침투속도가 빠름에도 불구하고 C/D 수문유형으로 분류됐다. 자갈이나 잔돌이 많은 마지통은 잔자갈이 존재하고 침투나 투수속도가 빠른 편으로 B유형이었다. 논으로 사용되는 안미통은 다른 석회암 유래토양에 비해 토층이 깊은 편이며 석회암 충적층에서 유래된 토양으로 선상지 및 곡간지에 분포한다. 관개된 상태에서 로타리 작업에 의해 표토의 특성이 교란되는 논으로 이용되는 특성 때문에 침투 및 투수속도는 느려 D유형으로 분류됐다. 잔돌이 존재하는 평안통은 석회암 붕적, 퇴적층으로부터 유래된 토양으로 산록경사지 및 선상단구에 분포하며 표토층인 A층에서 중 입상구조를 보이며 공극이 많고 작물뿌리가 매우 많아 침투속도는 빠르나 B층에서는 점토 함량이 감소했다 증가하면서 토성이 급격히 바뀌는 특성을 나타내 투수속도는 느린 값을 나타내 수문학적 토양유형은 D유형으로 분류됐다.

• 농업과학연구
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• 제50권4호
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• pp.967-976
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• 2023

Biochar is emerging as a promising substance for achieving carbon neutrality and climate change mitigation. It can absorb several nutrients via ion bonding on its surface functional groups, resulting in slow dissociation of the bonds. Biochar, like organic fertilizers, contributes to sustainable nutrient management. The purpose of this study was to investigate the effects of nutrient-coated biochar amendments on leafy vegetables production and soil fertility. The nutrient-coated biochar was produced by soaking rice husk biochar in a nutrient solution containing nitrogen (N), phosphorus, and potassium for 24 hours. Nutrient-coated biochar and organic fertilizers were applied to soil at a rate of 120 kg·N·ha^-1. The growth components of the leafy vegetables showed that nutrient-coated biochar led to the highest fresh weight (FW) of both lettuce and kale (i.e., 146.67 and 93.54 g·plant^-1 FW, respectively). As a result, nutrient-coated biochar amendments led to superior yield compared to the control treatment and organic fertilization. The elemental composition of leafy vegetables revealed that soil amended with nutrient-coated biochar resulted in higher nutrient contents, which was attributed to the high nutrient contents supplied by the rice husk biochar. Soil amendment with nutrient-coated biochar positively enhanced the soil fertility compared to amendment with organic fertilizer. Therefore, nutrient-coated biochar is a promising substance for enhancing agronomic performance of leafy vegetables and improving soil fertility.

• 한국환경보건학회지
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• 제46권1호
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• pp.1-10
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• 2020

Objectives: This study intends to evaluate the ecological risk of lead (Pb), arsenic (As), and their compounds according to the 2010 action plan on inventory and management for national priority chemicals and provide calculations of risks to the environment. By doing so, we aim to inform risk management measures for the target chemicals. Methods: We conducted species sensitivity distribution (SSD) analysis using the collected ecotoxicity data and obtained predicted no effect concentrations (PNECs) for the in-water environment using a hazardous concentration of 5% (HC5) protective of most species (95%) in the environment. Based on the calculated PNECs for aquatic organisms, PNEC values for soil and sediment were calculated using the partition coefficient. We also calculated predicted exposure concentration (PEC) from nation-wide environmental monitoring data and then the hazard quotient (HQ) was calculated using PNEC for environmental media. Results: Ecological toxicity data was categorized into five groups and five species for Pb and four groups and four species for As. Based on the HC5 values from SSD analysis, the PNEC value for aquatic organisms was calculated as 0.40 ㎍/L for Pb and 0.13 ㎍/L for As. PNEC values for soil and sediment calculated using a partition coefficient were 77.36 and 350.50 mg/kg for Pb and 24.20 and 112.75 mg/kg for As. The analysis of national environmental monitoring data showed that PEC values in water were 0.284 ㎍/L for Pb and 0.024 ㎍/L for As, while those in soil and sediment were respectively 45.9 and 44 mg/kg for Pb, and 11.40 and 19.80 mg/kg for As. Conclusions: HQs of Pb and As were 0.70 and 0.18 in water, while those in soil and sediment were 0.59 and 0.13 for Pb and 0.47 and 0.18 for As. With HQs <1 of lead and arsenic in the environment, their ecological risk levels are found to be low.

• 한국토양비료학회지
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• 제36권4호
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• pp.181-192
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• 2003

기상 자료와 토양 수리 특성을 입력하여 토양수분의 수직 이동 및 분포를 예측할 수 있는 수치모형을 개발하고, 이 모형을 검정하기 위해 중동사양토를 대상으로 추정한 결과와 중성자 산란법에 의해 측정한 수분단면을 비교하였다. 이 모형에서 토양수분 포텐셜을 기준으로 한 Richards 방정식의 해를 predictor-corrector 격자에 투영한 음함수 유한차분법에 의해 구하였다. 이 모형에서는 토양단면의 수리특성은 균질하고, 토양수분은 등온적으로 흐르고, 수분이력현상은 고려하지 않고, 수증기 및 열 이동은 일어나지 않고, 빗물은 토양 단면에 부분 치환원리에 의해 분배된다고 가정하였다. 이 모형의 입력 자료는 크게 강우량, 최고 및 최저 기온, 상대습도 및 일사량의 일일 기상자료와 불포화 수리전도도 및 수분보유 특성 함수를 추정하기 위한 토양 수리 자료로 구분하였다. Chebyshev 다항식과 최소 자승차를 이용하여 추정한 토양 수리 다항식은 입력 자료와 매우 잘 일치하였다. 다양한 지표 및 하부 경계조건에서 53일 동안 상대적으로 시간증가분을 크게 하여 추정한 Richards 방정식의 해인 토양수분 수직 단면은 지표 10 cm를 제외하고는 중성자 산란법에 의해 측정한 결과와 잘 일치하였다.

• 한국조경학회지
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• 제21권2호
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• pp.107-119
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• 1993

This study was conducted to increase to increase the plant species diversity, which was based on the analysis of plant community structure and the survey of human's disturbance degree in Mt. Yongma and Mt. Acha urban nature park, Seoul. The plant community were divided into four groups by TWINSPAN and DCA. These groups were Pinus rigida-P. densiflora community, Quercus mongolica-Q.aliena-Q.accutissima community, Robinia pseudoacaia-Q.accutissima-Poplus${\times}$albaglandulosa community and R.pseudoacacia community. The successional trends of tree species seems to be from P.densiflora, P.rigida, Sorbus alniflora to Q.mongolica, Q.aliena and from P.${\times}$albaglandulosa, R.pseudoacacia, through Q.accutissima, to Q. mongolica, Q.aliena. The species diversity of plant community was high in natual plant community but was low in artificial planting community respectively. Number of species, number of species individuals, indices of species diversity was lowered and soil hardness was increased by the user's trampling, undercutting work and planting P.koraiensis after thinning. In the basis of study results, we proposed the management plan for the urban forest.