• Journal of Ecology and Environment
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• 제32권4호
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• pp.295-304
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• 2009

To understand the properties of soil in Dokdo, we collected soil samples from 12 locations on Seodo and 23 locations on Dongdo, in Dokdo of Gyeongsangbuk-do Province in 2007-2008 and analyzed the soil's physical and chemical characteristics. Sand comprises the largest component (49.37%) of Dokdo soil, followed by silt (40.70%) and clay (9.93%). The soil structure consists mostly of sand loam, followed by loam and silt loam. The pH level of soils from Dokdo varied dramatically among sampling sites and seasons, ranging from 3.36 to 8.02. The total ion content of Dokdo soil also varies greatly among survey places and periods, but in general the total ion content was high in summer when vegetation develops, and low in spring. The exchangeable cation contents of the soil showed low levels in samples where the soil pH was low, including habitats dominated by Agropyron tsukushiense var. transiens and Echinochloa crus-galli, whereas the exchangeable cation contents were high where the organic contents were high, as in habitats dominated by Liriope platyphylla and Artemisia japonica subsp. littoricola. Soil N contents varied greatly among survey sites and higher N contents were found in soil inhabited by Chenopodiaceous plants than in habitats inhabited by other plants. The substantial differences in phosphorus contents among sites were related to excrement of black-tailed gulls. To understand the basic physical and chemical features of the soil on Dokdo, it will be necessary to conduct seasonal and long-term research on soil pH, ion contents, organic contents, N and P, as well as obtaining precise data from samples collected at different depths.

• 한국자원식물학회지
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• 제22권6호
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• pp.528-534
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• 2009

The study of germination and seedling growth characteristics of Neem under different soil and environment conditions was undertaken. The seed germination started 8 days after sowing in commercial bed soil, whereas, delayed germination was observed in sandy-loam (15 days) and sandy (19 days) soil. The highest germination (73.33%) was observed in commercial bed soil in green house, whereas, the lowest germination was observed in sandy soil (16.67%) and sandy-loam soil (8.33%). The seeds in the open field (sandy soil) also showed poor (10%) germination. The mean number of germination seed/day (GD) and seed germination vigor rate (GV) both were highest in the commercial bed soil with 0.733% and 16.67% respectively in the green house, whereas sandy and sandy-loam soil in green house and open field (sandy soil) all showed much lower GD and GV values. The seedling characteristics of nursery revealed that the seedling grown in the growth chamber in commercial bed soil was significantly higher in all the parameters comparing to others grown in green house and open field. The growth was nearly 7 fold in the chamber compared to that of the green house nursery observed in three months old seedlings. Likewise, HPLC analysis revealed that the green house grown seedling contain higher quantity of pigments compare to the chamber grown seedlings. Among the soils used the commercial soil alone or in combination with sandy and sandy-loam soil in the ratio of 2:1:1 respectively with the temperature of $27{\pm}2^{\circ}C$ showed better for Neem nursery preparation.

• KIEAE Journal
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• 제7권3호
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• pp.57-62
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• 2007

Most of current building materials are made of organic compounds or at least made with chemical treatments. Though easy to use and comparatively pay less, those materials are generally not enviornmentally sound. VOC is one of harmful effects. On contrary, natural materials such as soil are usually eco-friendly, and environmentally sustainable as well if not treated in autoclaves. Acoustica materials made of such environmentally sound and sustainable could be widely used. It is aimed to prove that soil based materials could be effectively used in acoustical fields rather than the other usual materials. Experiments with various types of soil blocks and soil plaster were performed. It is proved that the soil plaster has better apsorption features than cement plaster. Soil blocks have higher absorption cofficients than soil plaster, due to the thickness, and the absorption characteristics can be controlled by the design of the blocks.

• 한국토양비료학회지
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• 제49권5호
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• pp.434-439
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• 2016

Anthropogenic soil in cropland is formed in the process of subsoil reversal and the refill of soil into cropland. However, there was little information on the chemical properties within soil profiles in anthropogenic soil under rice paddy near the river. In this study, we investigated the chemical properties within soil profiles in the anthropogenic soil located at 4 sites in Gumi, Kimhae, Chungju, and Euiseong to compare with the natural paddy soil near the river. Among particle sizes, the sand content decreased under soil profiles but the silt and clay contents increased compared to the natural paddy soil in soil profiles. Organic matter content in topsoil of anthropogenic soil was lower than in that of natural soil, which was shown the contrary tendency within soil profiles. Also, the soil pH, available $P_2O_5$, and exchangeable cations were higher in anthropogenic soil compared to natural paddy soil at topsoil, which was maintained these tendency into soil depth. Nutrients may be equally distributed in anthropogenic soil during the process of refill in paddy soil near the river. This results indicated that anthropogenic soil would contribute to carbon sequestration, the mitigation of compaction, and reduction of fertilizer application in paddy soil. Therefore, characteristics of anthropogenic soil can be used for the soil management in cropland.

• 한국연초학회지
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• 제21권2호
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• pp.136-143
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• 1999

This study was conducted to evaluate the degradation characteristics of waste cigarette filters under 0, 5, 10, and 15cm in depth from soil surface by environmental conditions. Weather was the most important factor during degradation of waste cigarette filters in this study. Bulking of cellulose acetate filaments exposed on soil surface was observed after 2 months, but the form of filter was kept up after 12 months. The treated cigarette filters in soil landfill revealed a little different degradation pattern at each soil landfill depth, The sample in 5cm depth of soil was more degraded then other site. A fluffy appearance of cellulose acetate filaments in the control filter rods was also developed more strongly in soil landfill then on soil surface. From the observation of waste cigarette filters by scanning electron microscopy, much degradation of the fiber of waste cigarette filters could be ascertained in soil landfill. The weight of waste cigarette filters under 5cm from soil surface was reduced about 50%, and the tensile strength of the samples in soil surface and under 5cm from soil surface were reduced 66.0% and 92.4%, respectively. The microbial experiment date that the viable cell number in microbial population and cellulolytic microorganisms showed the maximum values under 5cm from soil surface, suggest that microorganisms in soil play an important roll in the degradation of acetate cigarette filters.

• 한국농공학회논문집
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• 제53권4호
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• pp.1-9
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• 2011

Forest area covers 64 % of the national land of Korea and the forest plays a pivotal role in the hydrological process such as flood, drought, runoff, infiltration, evapotranspiration, etc. In this study, soil moisture monitoring for conifer forest in experimental forest of Seoul National University has been conducted using FDR (Frequency Domain Reflection) for 6 different soil layers, 10, 20, 30, 60, 90 and 120 cm during 2009~2010, and precipitation data was collected from nearby AWS (Automatic Weather Station). Soil moisture monitoring data were used to estimate soil moisture recession constant (SMRC) for analyzing soil moisture recession characteristics. From the results, empirical soil moisture recession equations were estimated and validated to determine the feasibility of the result, and soil moisture contents of measured and calculated showed a similar tendency from April to November. Thus, the results can be applied for soil moisture estimation and provided the basic knowledge in forest soil moisture consumption. Nevertheless, this approach demonstrated applicability limitations during winter and early spring season due to freezing and melting of snow and ice causing peculiar change of soil moisture contents.

• 한국환경과학회지
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• 제30권12호
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• pp.1015-1025
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• 2021

Our research work aimed to evaluate cover crop effects of winter rye on soil characteristics, soil conservation, and yield productivities on potato fields with 15% slope during a fallowed period. There were two controls of bared field without any cultivation and conventional potato cultivation without winter rye. Potato cultivation increased soil pH, organic matter, available phosphate, and exchangeable cation regardless of cover crop cultivation. Sub-soil, particularly, all components of soil chemical properties showed higher value in winter rye cultivation than conventional cultivation. Higher soil density was observed on cover crop cultivation than conventional cultivation resulting from root residues of the cover crop both topsoil and subsoil. Cover crop residues positively affected plant growth and reduced the amount of soil erosion by holding the soil. Although severe soil erosion was seen in conventional cultivation, winter rye cultivation declined soil erosion by 47% during the fallow period on potato slope fields. Distinct soil bacterial communities were detected among treatments and some OTU(Operational Taxonomic Unit)s showed significantly higher abundance in winter rye treatment. Total yield and commercial rate demonstrated no significant differences while higher tuber phosphate, K⁺, and Mg²⁺ contents were observed in winter rye cultivation.

• 한국건설순환자원학회논문집
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• 제8권2호
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• pp.153-160
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• 2020

본 연구에서는 이산화탄소 포집광물을 심층혼합처리용 Soil-cement로 활용하기 위하여 최적 Soil-cement의 배합비를 도출하였으며, 이산화탄소 포집광물이 혼합된 Soil-cement의 품질특성을 평가하였다. 이산화탄소 포집광물은 슬러리 형태로 발생되며, 함수량 평가결과, 약 50%로 나타났다. 따라서, Soil-cement의 배합시 단위수량에서 이산화탄소 포집광물의 함수량을 제외하였다. 이산화탄소 포집광물 활용 Soil-cement를 현장토에 대하여 현장배합을 실시한 결과 재령 28일 기준 3.0MPa 이상을 나타냄으로써 설계 허용지지력 기준을 만족하는 것으로 나타났다. 이산화탄소 포집광물의 유해성 검증을 실시한 결과 구리(Cu)의 경우 0.055mg/L 검출되었지만 허용기준치에 만족하였으며, 이 외의 유해 물질은 용출되지 않은 것으로 분석되었다.

• Journal of Ecology and Environment
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• 제42권1호
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• pp.20-29
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• 2018

Background: For various reasons such as agricultural and economical purposes, land-use changes are rapidly increasing not only in Korea but also in the world, leading to shifts in the characteristics of local carbon cycle. Therefore, in order to understand the large-scale ecosystem carbon cycle, it is necessary first to understand vegetation on this local scale. As a result, it is essential to comprehend change of the carbon balance attributed by the land-use changes. In this study, we attempt to understand accumulated soil carbon (ASC) and soil respiration (Rs) related to carbon cycle in two ecosystems, artificially turned forest into pastureland from forest and a native deciduous temperate forest, resulted from different land-use in the same area. Results: Rs were shown typical seasonal changes in the alpine pastureland (AP) and temperate deciduous forest (TDF). The annual average Rs was $160.5mg\;CO_2\;m^{-2}h^{-1}$ in the AP, but it was $405.1mg\;CO_2\;m^{-2}h^{-1}$ in the TDF, indicating that the Rs in the AP was lower about 54% than that in the TDF. Also, ASC in the AP was $124.49Mg\;C\;ha^{-1}$ from litter layer to 30-cm soil depth. The ASC was about $88.9Mg\;C\;ha^{-1}$, and it was 71.5% of that of the AP. The temperature factors in the AP was high about $4^{\circ}C$ on average compared to the TDF. In AP, it was observed high amount of sunlight entering near the soil surface which is related to high soil temperature is due to low canopy structure. This tendency is due to the smaller emission of organic carbon that is accumulated in the soil, which means a higher ASC in the AP compared to the TDF. Conclusions: The artificial transformation of natural ecosystems into different ecosystems is proceeding widely in the world as well as Korea. The change in land-use type is caused to make the different characteristics of carbon cycle and storage in same region. For evaluating and predicting the carbon cycle in the vegetation modified by the human activity, it is necessary to understand the carbon cycle and storage characteristics of natural ecosystems and converted ecosystems. In this study, we studied the characteristics of ecosystem carbon cycle using different forms in the same region. The land-use changes from a TDF to AP leads to changes in dominant vegetation. Removal of canopy increased light and temperature conditions and slightly decreased SMC during the growing season. Also, land-use change led to an increase of ASC and decrease of Rs in AP. In terms of ecosystem carbon sequestration, AP showed a greater amount of carbon stored in the soil due to sustained supply of above-ground liters and lower degradation rate (soil respiration) than TDF in the high mountains. This shows that TDF and AP do not have much difference in terms of storage and circulation of carbon because the amount of carbon in the forest biomass is stored in the soil in the AP.

• 한국농공학회논문집
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• 제58권3호
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• pp.47-56
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• 2016

Superabsorbent Polymers (SAPs) are hydrophilic synthetic polymers which could absorb water by hundreds of their own weight. They are used for multiple purpose including hygienic goods, soil conditioners, and hospital supplies. It is necessary to investigate the standard of their use including the amendment rate for soil application in agricultural fields. It is also important to understand their effects on the soil water content and engineering characteristics. The objective of this study is to find the water absorbing capacity and reusability of SAPs, and the characteristics of water release and effect of them on soil water content and engineering characteristics. In the result, SAPs per unit weight (1 g) used for this research could absorb about 200 g of water in max. The water absorbing capacity decreased after SAPs were used repeatedly. Released water of SAPs could provide the soils with about 9 % of the soil water content. Soil water content increased with decreasing distance from the SAPs. The distance of release was spreaded out with increasing water absorbed of SAPs. Finally, when a drainage and the capacity of soil water content were considered, it is recommended to amend the SAPs with soil by less than 0.25 %.