• Animal cells and systems
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• 제10권4호
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• pp.191-196
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• 2006

This study was carried out to evaluate soil carbon cycling of a 36-year-old larch (Larix leptolepis) stand in Korea. The aboveground and soil organic carbon storage, litterfall, and soil respiration rates were measured over twoyear periods. The estimated aboveground biomass carbon storage and increment were 4220 gC $m^{-2}$ and 150 gC $m^{-2}\;yr^{-1}$, respectively. Mean organic carbon inputs by needle and total litterfall were 118 gC $m^{-2}\;yr^{-1}$ and 168 gC $m^{-2}\;yr^{-1}$, respectively. The aboveground carbon increment of the stand was similar to the annual input of carbon from total litterfall. The soil respiration rates correlated exponentially with the soil temperature at a depth of 20 cm ($R^2$ = 0.86). In addition, the exponential regression equation indicated a relatively strong positive relationship between the soil respiration rates and soil temperature, while there was no significant relationship between the soil respiration rates and the soil moisture content. The annual mean and total soil respiration rates were 0.40 g $CO_2\;m^{-2} h^{-1}$ and 3010 g $CO_2\;m^{-2}\;yr^{-1}$ over the two-year study period, respectively.

• 농업과학연구
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• 제47권4호
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• pp.1097-1107
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• 2020

Assessment of soil carbon stock is essential for climate change mitigation and soil fertility. The digital soil mapping (DSM) is well known as a general technique to estimate the soil carbon stocks and upgrade previous soil maps. The aim of this study is to calculate the soil carbon stock in the top soil layer (0 to 30 cm) in Jeolla Province of South Korea using the DSM technique. To predict spatial carbon stock, we used Cubist, which a data-mining algorithm model base on tree regression. Soil samples (130 in total) were collected from three depths (0 to 10 cm, 10 to 20 cm, 20 to 30 cm) considering spatial distribution in Jeolla Province. These data were randomly divided into two sets for model calibration (70%) and validation (30%). The results showed that clay content, topographic wetness index (TWI), and digital elevation model (DEM) were the most important environmental covariate predictors of soil carbon stock. The predicted average soil carbon density was 3.88 kg·m-2. The R2 value representing the model's performance was 0.6, which was relatively high compared to a previous study. The total soil carbon stocks at a depth of 0 to 30 cm in Jeolla Province were estimated to be about 81 megatons.

• 한국토양비료학회지
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• 제39권6호
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• pp.396-402
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• 2006

토양 유기탄소는 토양의 질 및 토양 비옥도의 평가 또는 시비량의 결정 등에 주요한 요인으로 고려되어 왔으며 온실가스의 방출 및 지구 온난화에 영향을 주고 있다. 따라서 토양 유기탄소의 적절한 관리는 토양의 질을 향상시키는 것뿐만 아니라 온실가스원을 관리하는 차원에서 중요성이 더욱 강조되고 있다. 이 연구의 목적은 압력센서를 이용한 무기탄소 측정 장치를 이용하여 토양중 무기탄소량을 측정하고 건식연소법과 습식연소법을 이용하여 석회암에서 유래된 토양의 유기탄소을 분석 비교 하고자 하였다. 건식연소법으로 측정된 총탄소의 값에서 무기탄소 측정장치를 통해 얻어진 무기탄소값을 뺀 값을 유기탄소량으로 계산하였다. 탄산석회 ($CaCO_3$)를 이용한 무기탄소 표준시료의 양과 개발된 무기탄소 측정장치 출력 값 간에 매우 유의한 직선의 관계가 얻어졌다. 충청북도 및 강원도 일대 석회암 지역에서 채취한 토양시료를 이용하여 건식연소법과 무기탄소 분석 장치를 이용하여 탄소함량을 분석한 결과 총 탄소 중량대비 약 22-28%의 무기탄소가 관측되었다. 습식연소법과 건식연소법으로 측정한 토양의 유기탄소간에 유의한 상관관계를 나타냈다. 결론적으로 개발된 토양무기탄소 분석장치는 토양 중 무기탄소의 간편한 측정을 통하여 석회암등에서 유래된 토양의 유기탄소를 효과적으로 분석하는데 기여할 수 있다.

• Journal of Ecology and Environment
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• 제29권1호
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• pp.23-27
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• 2006

This study was conducted to evaluate forest carbon cycling and soil $CO_2$ efflux rates in a 42-year-old pine (Pinus densiflora) stand located in Hamyang-gun, Korea. Aboveground and soil organic carbon storage, litterfall, litter decomposition, and soil $CO_2$ efflux rates were measured for one year. Estimated aboveground biomass carbon storage and increment in this stand were $3,250gC/m^2\;and\;156gC\;m^{-2}yr^{-1}$, respectively. Soil organic carbon storage at the depth of 30 cm was $10,260gC/m^2$ Mean organic carbon inputs by needle and total litterfall were $176gC\;m^{-2}yr^{-1}\;and\;235gC\;m^{-2}yr^{-1}$, respectively. Litter decomposition rates were faster in nne roots less than 2 mm diameter size ($<220\;g\;kg^{-1}yr^{-1}$) than in needle litter ($<120\;g\;kg^{-1}yr^{-1}$). Annual mean and total soil respiration rates were $0.37g\;CO_2m^{-2}h^{-1}$ and $2,732g\;CO_2m^{-2}yr^{-1}$ during the study period. A strong positive relationship existed between soil $CO_2$ efflux and soil temperature (r=0.8149), while soil $CO_2$ efflux responded negatively to soil pH (r=-0.3582).

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.340-340
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• 2017

Rice straw is very important to maintain fertility in agricultural soil with several aspects such as carbon and nitrogen cycles in Korea. Recently, concerning about climate change, carbon sequestration in agricultural land has become one of the most interesting and debating issues. Rice straw is most representative source of organic material produced in agricultural sectors. In order to evaluate changes of soil carbon treated by rice straw during cultivating rice in paddy field, we carried out to treat rice straw with 0, 0.5, 1, 1.5, and $2.0ton\;ha^{-1}$ at $50{\times}50{\times}20cm$ blocks made of wood board, and analyze contents of fulvic acid and humic acid form, and total carbon periodically. The experiment was conducted in 2013-2016, and sampled with interval in a month. The organic material was applied to treatment blocks in 2 weeks ago in rice transplanting of each year. Total carbon in beginning time is low as $7.9g\;kg^{-1}$. The contents of total carbon with treatments of rice straw after experiment are recorded as 8.7, 11.2, 9.5, 10.5, and $10.9g\;kg^{-1}$ applied by 0, 0.5, 1, 1.5, and $2.0ton\;ha^{-1}$, respectively. When trend lines were calculated on changes of soil carbon in periods of experiments, The trend equations of soil carbon changes with treatments of 0, 0.5, 1, 1.5, and $2.0ton\;ha^{-1}$ were Y=0.0015X+8.479, Y=0.073X+8.2577, Y=0.0503X+8.4477, Y=0.0822X+8.2103, and Y=0.082X+8.5736. These trends suggested several results. When rice straw was applied in cultivating paddy fields, most carbon in rice straw would be decomposed regardless the amount of rice straw in soil. We calculated sequestration rate of applied rice straw as about 0.1% per year during rice cultivation in paddy fields. It means that if farmer want to increase 1% soil organic matter by using application of rice straw returned after cultivation, famer should apply rice straw continuously for ten years. The change of soil carbon as fulvic acid, humic acid, and humane is showed that only content of carbon as mumine is increased significantly while fulvic acid and humic acid were changed in range of 10 to 30% among total carbon in soil. In conclusion, to sequestrate soil carbon with rice straw, it is important for rice straw to apply continuously every year. The amount of rice straw applied is not much effected to increase soil organic matter.

• 농업과학연구
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• 제48권4호
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• pp.891-897
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• 2021

There is a need for a technology that can quickly and accurately analyze soil carbon contents. Existing soil carbon analysis methods are cumbersome in terms of professional manpower requirements, time, and cost. It is against this background that the present study leverages the soil physical properties of color and water content levels to develop a model capable of predicting the carbon content of soil sample. To predict the total carbon content of soil, the RGB values, water content of the soil, and lux levels were analyzed and used as statistical data. However, when R, G, and B with high correlations were all included in a multiple regression analysis as independent variables, a high level of multicollinearity was noted and G was thus excluded from the model. The estimates showed that the estimation coefficients for all independent variables were statistically significant at a significance level of 1%. The elastic values of R and B for the soil carbon content, which are of major interest in this study, were -2.90 and 1.47, respectively, showing that a 1% increase in the R value was correlated with a 2.90% decrease in the carbon content, whereas a 1% increase in the B value tallied with a 1.47% increase in the carbon content. Coefficient of determination (R²), root mean square error (RMSE), and mean absolute percentage error (MAPE) methods were used for regression verification, and calibration samples showed higher accuracy than the validation samples in terms of R² and MAPE.

• 한국지반환경공학회 논문집
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• 제22권3호
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• pp.37-43
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• 2021

본 연구는 토지피복의 변화에 따른 토양 탄소의 변화량을 산정하고자 하였다. 다양한 토양탄소 모형가운데 InVEST Carbon Storage and Sequestration 모듈을 사용하였다. 토지피복은 토양 탄소에 영향을 주는 대표적인 인자 중 하나이다. 따라서 본 연구에서는 대한민국 전역을 대상으로 2000년과 2010년의 토지피복 변화에 따른 토양 탄소의 총량을 비교하였으며, 각 행정구역별(시도)의 변화량을 산정하였다. 대한민국의 토지피복 변화는 주로 시가 및 건조지역의 증가와 초지의 감소 등으로 나타났으며, 이로 인한 토양 탄소의 변화를 나타냈다. 대한민국의 총 토양 탄소 변화량은 10년 사이 11.48(million t) 감소한 것으로 나타났다. 행정구역별 토양탄소량은 대부분의 시도에서 감소를 나타냈으나, 예외적으로 제주도는 토양탄소량이 증가한 것으로 나타났다. 제주도를 제외한 시도 중 감소량이 제일 적은 시도는 서울로 나타났으며, 감소량은 0.033(million t)으로 나타났다. 반대로 가장 많은 감소량을 보인 시도는 경북으로 총 2.893(million t)이 감소하였다. 제주도는 유일한 총 토양 탄소 증가 지역으로 0.547(million t)이 증가하였으며, 10년 사이 농업지역이 2.1배 증가함을 보였다. 토양탄소의 경우 전국단위의 실측 자료 구축이 부족함을 보이며, 추후 다중 모형을 이용하여 연계분석을 통해 검증을 진행해야 할 것이다.

• 한국환경복원기술학회지
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• 제12권2호
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• pp.1-9
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• 2009

Due to the increase of carbon dioxide in the atmosphere and global warming, the importance of forest ecosystems, as a place of carbon accumulation and emission, has received a great amount of recognition lately. This study was performed to help understand and provide the current status of carbon cycle in the pinus densiflora stand, Korea. The samples were collected from average 35-years-old Pinus densifiora rands in Gongju, Youngdong, Chungsan, Muju, Mupung, and Jangsu regions. Total thirty aboveground sample trees were cut, and ten roots were sampled, and soil samples were collected. Average carbon concentrations in foliage, branch, stem bark, stem wood, and root were 55.7%, 56.0%, 56.0%, 57.3%, and 56.5%, respectively. Carbon content was estimated by the model $Wt=aD^b$ where Wt is oven-dry weight in kg and D is DBH in cm. Total carbon content (aboveground and root) was 42.39tonC/ha in the Pinus densiflora stand. The proportion of each tree component to total carbon content was high in order of stemwood, root, branch, stem bark, and foliage. Total net primary production (aboveground and root) was estimated at 6.51tonC/ha/yr in Pinus densiflora stand. The proportion of each tree component to total net primary carbon content was high in order of sternwood, root, branch, foliage and stembark. Soil carbon contents in the study sites was 43.51tonC/ha at 0-50cm soil depth.

• 한국토양비료학회지
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• 제50권1호
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• pp.65-70
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• 2017

Soil was regarded as infinite resources but recently, soil is considered as invaluable resources that we need to protect and conserve. Main objective of this research was to evaluate soil value in terms of soil carbon contents. Soil was classified into forest, paddy, upland, and grass. Carbon contents in each soil was calculated based on soil chemical properties. Calculated soil carbon contents was ranged $15.31-108.86mg\;kg^{-1}$. Based on soil carbon contents, soil value was assumed adapting economic concepts. Calculated total soil value based on soil carbon contents was about 18.46 trillion won. Among others, carbon contents in forest was the highest and value was assumed 11.95 trillion won followed by paddy field (3.7 trillion won).

• 자원환경지질
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• 제54권4호
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• pp.409-425
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• 2021

이산화탄소가 지구온난화를 초래하는 대표적인 온실가스로 지목되면서 대기 중의 이산화탄소 농도를 줄이기 위하여 많은 노력들이 진행되어 왔다. 그러한 노력들 중 특히 CO₂ 포집 및 지중 저장기술(carbon dioxide capture and storage, CCS)이 감축 목표량을 달성하기 위해서 필수적으로 고려되고 있다. 그러나 이러한 지중 저장기술이 상용화되기 위해서는 안전성이 보장되어야 한다. 특히 이산화탄소 누출이 농경지에서 발생할 경우에는 작물 생장과 관련되어 많은 문제를 야기할 수 있다. 이에 본 연구에서는 지중 저장지로부터 누출된 이산화탄소가 토양 비옥도에 미치는 영향에 대하여 고찰하였다. 이를 위하여 인위적인 이산화탄소 누출 시험을 수행하였으며, pH, 양이온치환용량, 교환성 양이온, 전기전도도, 토양 유기물 함량, 총 질소, 질산태 질소, 암모니아태 질소, 총 인, 유효태 인산, 총 황, 유효태 황, 유효태 붕소 등과 같은 토양의 화학적 특성들을 비옥도 지시 인자로 선정하였다. 누출 시험은 비경작지 토양 한 종류와 경작지 토양 두 종류(옥수수와 콩 재배)를 대상으로 이루어졌다. 비경작지 토양은 거친 모래가 많은 사질토양으로 공극률은 42.6%로 조사되었으며, 경작지 토양인 옥수수 재배 토양은 양질 사토(loamy sand)로 공극률이 46.8%이었다. 콩과식물(soybean) 재배 토양은 옥수수 재배 토양과 동일한 양질 사토로서 공극률이 48%로 조사되었다. 누출시험을 위해 6개의 인공누출 칼럼 장치를 이용하여 이산화탄소를 주입하였다. 이산화탄소 주입은 비경작지와 경작지 토양의 경우 각각 60일과 70일 동안 진행하였다. 이산화탄소 누출 후 비경작지 및 경작지 토양에 대하여 각각 12, 14일 간격으로 1 공극 부피의 인공강우 모사 시험을 수행한 후 용출액과 토양 시료를 채취하여 비옥도 지시 인자를 분석하였으며, 이산화탄소 누출 전후 변화 양상을 비교 평가하였다. 토양 내 잔류 교환성 양이온, 전기전도도, 토양 유기물 함량, 총질소, 총인 등은 이산화탄소의 영향을 크게 받지 않은 것으로 나타났다. 그러나 질산태 질소, 암모니아태 질소, 유효 인산, 유효 황, 유효 붕소 등은 감소하는 경향을 보였으며 이에 의해 토양 비옥도를 저하시킬 수 있을 것으로 판단된다. 본 연구에서는 토양의 완충능력 때문에 pH의 변화가 없었지만, 이산화탄소가 장기간 누출된다면 pH의 감소에 의한 토양 산성화가 초래될 가능성이 있을 것으로 예측된다.