• Korean Journal of Agricultural and Forest Meteorology
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• v.20 no.4
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• pp.357-365
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• 2018

This study was carried out to evaluate the weight loss rates, carbon and nitrogen dynamics of wood stakes following soil amendment treatments (CLB: compound fertilizer + lime + biochar; LB: lime + biochar) in a post-fire restoration area, Ulsan Metropolitan city, southern Korea. Soil amendments in the fire-disturbed area were applied to two-times (Mar. and Jun. 2015, 2016) during the study period. Wood stakes on Mar. 2015 were buried at a top 15cm of mineral soil in two soil amendment and control treatments of Liriodendron tulipifera, Prunus yedoensis, Quercus acutissima, Pinus thunbergii plantations and an unplanted area in the post-fire restoration area. Wood stakes were collected at Oct. 2015, Mar. 2016 and Oct. 2016 to measure weight loss rates, organic carbon and nitrogen concentrations. Weight loss rates of wood stakes were not significantly affected by soil amendment treatments. However, remaining carbon of wood stakes were lowest in the control treatment (43.7%), followed by the CLB (71.3%) and the LB (71.6%) treatments. Remaining nitrogen of wood stakes was less in the control treatment (29.7%) compared with the LB treatment (52.6%). The results indicate that carbon and nitrogen mineralization of wood stakes in post-fire restoration area were delayed by soil amendment treatments.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.12
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• pp.897-905
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• 2013

In this study, sorption coefficients (${\log}K_{OC}$, n) for the binding of phenanthrene (PHE) to soil humins, insoluble fraction of soil humc substances (HS), were determined and relationship between the sorption coefficients and structural characteristics of the soil humins were investigated. The soil humins used in the present study were isolated from 7 different soils including 5 domestic soils, an IHSS standard and a peat soil, and characterized by elemental analysis and CPMAS $^{13}C$ NMR method. $^{13}C$ NMR spectral features indicate that the soil humins are mainly made up of aliphatic carbons (57.1~72.3% in total carbon) with high alkyl-C moiety, and the alkyl-C contents ($C_{Al-H,C}$, %) was in order of granite soil Hu (26~42%) > volcanic ash soil, HL Hu (23.9%) > Peat Hu (14.0%). The results of correlation study show that a positive relationship ($r^2$ = 0.77, p < 0.05) between organic carbon normalized-sorption coefficients ($K_{OC}$, mL/g) and alkyl-C contents($C_{Al-H,C}$, %), while negative relationship ($r^2$ = (-)0.74, p < 0.05) between Freundlich sorption parameter (n) and H,C-substituted aromatic carbon contents ($C_{Ar-H,C}$, %). The magnitude of $K_{OC}$ values are also negatively well correlated with polarity index (e.g., PI, N + O)/C) ($r^2$ = (-)0.74, p < 0.1). These results suggest that the binding capacity (e.g., $K_{OC}$) for PHE is increased in soil humin molecules having high contents of alkyl-C or lower polarity, and nonlinear sorption for PHE increased as the H,C-substituted aromatic carbon contents ($C_{Ar-H,C}$, %) in the soil humins increased. The PHE sorption characteristics on soil humins are discussed based on the dual reactive mode of sorption model.

• Korean Journal of Environmental Biology
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• v.35 no.4
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• pp.715-725
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• 2017

Importance of climate change and its impact on agriculture and environment has increased with the rise in the levels of Green House Gases (GHGs) in the atmosphere. To slow down the speed of climate change, numerous efforts have been applied in industrial sectors to reduce GHGs emission and to enhance carbon storage. In the agricultural sector, several types of research have been performed with emphasis on GHGs emission reduction; however, only a few work has been done in understanding the role of carbon sink on reduction in GHGs emission. In this study, we investigated ecosystem carbon balance and soil carbon storage in an agricultural paddy field. The results obtained were as follows: 1) Evaluation of soil C sequestration in paddy field was average $3.88Mg\;CO_2\;ha^{-1}$ following NPK+rice straw compost treatment, average $3.22Mg\;C\;ha^{-1}$ following NPK+hairy vetch treatment, and average $1.97Mg\;CO_2\;ha^{-1}$ following NPK treatment; and 2) Net ecosystem production (NEP) during the paddy growing season was average $14.01Mg\;CO_2\;ha^{-1}$ following NPK+hairy vetch treatment, average $12.60Mg\;CO_2\;ha^{-1}$ following NPK+rice straw compost treatment, and average $11.31Mg\;CO_2\;ha^{-1}$ following NPK treatment. Therefore, it is proposed that organic matter treatment can lead to an increase in soil organic carbon accumulation and carbon sock of crop ecosystem in fields compared to chemical fertilizers.

• Journal of Soil and Groundwater Environment
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• v.13 no.2
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• pp.21-29
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• 2008

Sorption and desorption processes play an important role in the transport and fate of organic contaminants in subsurface system. In this study, sorption and desorption characteristics of atrazine in 7 soils selected at the Gwangju area were investigated. Soil organic carbon contents ranged from 0.42 to 2.82%. Sorption and desorption experiments were performed in batch slurries. Sorption distribution coefficient ($K_d$) of atrazine were ranged from 0.48 to 3.26 l/kg and $K_d$ value increased with increasing organic carbon contents except of Kyongbang and Youngdong soils. Single desorption data were analyzed by the three-site desorption model including equilibrium, non-equilibrium and non-desorbable site. Non-desorbable site fractions of atrazine in all soils were enumerated and non-desorbable atrazine was observed in seriesdilution desorption experiment. Sorption/desorption hysteresis was also observed in the series-dilution desorption experiment.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 1998.06a
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• pp.91-95
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• 1998

본 연구의 목적은 산업활동에 많이 이용되고 환경학적으로 난분해성으로 알려졌으며, 특히 일반적인 미생물에 위한 생분해가 용이하지 않은 대표적인 방향족 화합물인 아조염료의 생분해능이 우수한 방선균을 토양에서 분리하여 그 분해특성을 연구하는데 있다. 본 연구실에서는 용인지역에서 무작위로 채취한 토양에서 방선균들을 분리하고, 이들중 아조계 화합물의 생분해능이 우수한 토양방선균 AD001을 대표적인 아조계화합물인 censored를 model compound로 이용하여 분리해 내었다. 방선균 AD001은 congored가 포함된 agar배지에서 censored를 아주 우수하게 decolorization 시킴이 관찰되었다. 이미 아조염료를 우수하게 분해한다고 알려져 있는 Streptomyces viridosporus T7A와 비교 실험을 수행한 결과, S. viridosporus는 cellulose를 탄소원으로 사용할 때 확실한 congored의 decolorization을 보인 반면 AD001의 경우 sucrose를 탄소원으로 사용할 때 더욱 뚜렷한 congored의 decolorization 현상이 관찰되었다. 또한 이런 분해특성의 특이성을 관찰하기 위해 구조적으고 상이한 new fuchsin으로 실험한 결과, 염료의 농도를 0.005% 주었을 때 S. viridosporus는 성장을 하지 못한 반면 AD001의 경우 배지에 포함된 new fuchsin을 확실하게 decolorization 시킴도 관찰할 수 있었다. 이러한 실험결과는 토양 방선균 AD001이 환경학적으로 아주 유용하게 이용될 수 있음을 제시하고 있다.

• Journal of Korean Society of Forest Science
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• v.110 no.4
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• pp.554-568
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• 2021

Forests are the largest carbon (C) sinks in terrestrial ecosystems. Recently, as enhancing forest C sequestration capacity has been proposed as a basic direction of the Republic of Korea's "2050 Carbon Neutral Strategy," accurate estimation of forest C sequestration has been emphasized. According to the Intergovernmental Panel on Climate Change guidelines, sequestration quantity is calculated from changes in C stocks in forest C pools, such as biomass, deadwood, litter and soil layer, and harvested wood products. However, in Korea, only the overstory biomass increase is now considered the amount of sequestration quantity, so there can be a significant difference from the actual forest C sequestration. In this study, we quantified forest C exchange through C flux measurement using an eddy covariance system and an automated soil chamber system in a 57-year-old Korean pine plantation located in Mt. Taehwa, Gwangju-si, Gyeonggi-do. Then, the net amount of C sequestration was compared with the amount of the overstory biomass increase. We estimated the annual C stock change in the remaining C pools by comparing the net sequestration amount from the C flux measurement with the overstory biomass increase and C stock change in the litter layer. Therefore, the net C sequestration of the Korean pine plantation estimated from the flux measurement was 5.96 MgC ha^-1, which was about 2.2 times greater than 2.77 MgC ha^-1 of the overstory biomass increase. The annual C stock increase in the litter layer was estimated to be 0.75 MgC ha^-1, resulting in a total annual C stock increase of 2.45 MgC ha^-1 in the remaining C pools. Our results indicate that the domestic forest is a larger C sink than the current methods, implying that more accurate calculations of the C sequestration capacity are necessary to quantify C stock changes in C pools along with the C flux measurement.

• Journal of Soil and Groundwater Environment
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• v.10 no.3
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• pp.46-51
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• 2005

This study was to evaluate sorption and biodegradation rate affecting the natural dissipation of chlorinated volatile organic compounds (CVOCs) in surface soil. To show the effect of sorption and biodegradation on the natural dissipation of 1,1,1-trichloroethane (TCA), trichloroethylene (TCE) and tetrachloroethylene (PCE), three types of vial experiments were employed; (1) sterilized, (2) non-sterilized, (3) non-sterilized/substrate enriched. Also three moisture contents was applied to find the moisture effect in each vial; (1) wilting point (12%, w/w), (2) field capacity (29%, w/w), (3) saturation (48%, w/w). The results suggested that keeping the soil moisture content at field capacity was desirable for TCA and TCE natural dissipation in the vial study.

• Korean Journal of Environmental Agriculture
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• v.32 no.4
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• pp.260-267
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• 2013

BACKGROUND: In most studies, soil carbon sequestration has been evaluated simply with change of soil organic carbon content. So far, information regarding stability of soil organic carbon is limited. METHODS AND RESULTS: This study was conducted to determine changes in soil organic carbon (SOC) content and stability of carbon in response to compost application rates and plastic mulching treatment during the hot pepper growing season. Under the pot experiment condition, compost was mixed with an arable soil at rates corresponding to 0, 10, 20, and 40 Mg/ha. To determine effects of plastic mulching on soil carbon sequestration, plastic mulching and no mulching treatments were set up in soils amended with the application rate of 20 Mg/ha. The SOC content did not significantly increase with application of compost and plastic mulching at harvest time. No significant changes in bulk density with compost application and plastic mulching was found. These might result from short duration of experiment. While hot water extractable organic carbon content significantly decreased with compost application and plastic mulching, humic substances increased. Belowground biomass of hot pepper was biggest at the recommended application rate (20 Mg/ha) of compost. CONCLUSION: From the above results, continuous application of compost at the recommended application rate could improve increase in SOC content and stability of carbon in long term aspect.

• Journal of Soil and Groundwater Environment
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• v.13 no.5
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• pp.74-80
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• 2008

Heavy metals, Cd and Pb, in soil were extracted by using anionic surfactants such as AOS (alpha olefin sulfonate), SDS (sodium dodecyl sulfate), and LAS (linear alkyl benzene sulfonic acid). Metal extractability from soil was affected by the carbon number and solution pH of surfactants. LAS showed higher metal extractability due to the acidic solution condition. Although SDS has a fewer carbon number than AOS, it would produce smaller micelles and resulted in more efficient extraction of metals by increased soil contact. Cd extractability of surfactant was twice enhanced by adding NaI as a ligand. However, Pb extractability of surfactant was sometimes reduced by adding NaI. Those ligand effects were dependent on solubility of metal-ligand. The column experiment also showed that SDS having smaller micelles resulted in higher metal extractability than AOS.

• The Korean Journal of Ecology
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• v.28 no.5
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• pp.265-270
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• 2005

In order to investigate the organic carbon distribution, net primary production, annual litter production, organic carbon in litter layer, soil organic carbon and soil respiration were studied in an oak forest, Kongju, Chungnam Province in Korea. Net primary production was estimated to 15.84 ton $C{\cdot}ha^{-1}{\cdot}yr^{-1}$. The amount of carbon allocated to leaf and reproductive organ, branch, stem and root was 1.71, 4.03, 7.34, 2.76 ton $C{\cdot}ha^{-1}{\cdot}yr^{-1}$ respectively. Annual litter production was 5.21 $ton{\cdot}ha^{-1}{\cdot}yr^{-1}$, which amounted to 2.35 ton $C{\cdot}ha^{-1}{\cdot}yr^{-1}$. Average amount of organic carbon in litter layer (L+F) was 6.06 ton C/ha, and that of L layer decreased from winter through summer. Soil organic carbon decreased along the soil depth. Average amount of soil organic carbon in this oak forest was 165.19 ton C/ha. The amount of carbon evolved through soil respiration was 11.24 ton $C{\cdot}ha^{-1}{\cdot}yr^{-1}$. Net amount of 4.60 ton $C{\cdot}ha^{-1}{\cdot}yr^{-1}$ was absorbed from the atmosphere by this oak forest.