• Korean Journal of Plant Resources
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• v.23 no.2
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• pp.179-186
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• 2010

This study was conducted to provide basic information for conservation and restoration through investigation of vegetation and soil condition of Megaleranthis saniculifolia Ohwi, Korean endemic species, in Mt. Halla, Jeju Island. Very few individuals were discontinuously distributed and restricted at 1,075 m above sea level, very steep slope ($60-70^{\circ}C$), rocky area of north face of Eorimok Valley. For investigation of environmental condition, we established two $10\;{\times}\;10\;m$ quadrats in the habitats and one control quadrat. Twenty-four species were found at site 1 under 10-12 m Carpinus laxiflora tree layer (35%) and soil conditions are pH 5.9, moisture content (field capacity) 9.39%, organic carbon 8.22% and organic matter 14.17%, respectively. Site2, 15 taxa were found under 8-12 m Platycarya strobilacea tree layer (40%) and soil conditions are pH 5.07, moisture content 4.99%, organic carbon 5.34% and 9.21 percentage of organic matter. In the control quadrat, 14 taxa were found under 10 m Carpinus laxiflora tree layer (10%) and soil conditions are pH 5.27, moisture content 6.23%, organic carbon 4.74% and organic matter 8.17%, respectively. The principal causes of threat which were investigated in this study are competition among company, very steep slopes, artificial management of valley. For restoration and conservation of habitats, it is needed to suitable plans.

• Korean Journal of Environmental Biology
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• v.22 no.3
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• pp.400-404
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• 2004

Polycaprolactone (PCL), a synthetic aliphatic polyester, was buried in activated sludge soil for 66 days at $27^\circ{C}$ and $37^\circ{C}$. The morphology of the surface of PCL film degraded by soil microorganisms was observed. Soil microorganisms degrading PCL were isolated and identified. Soil fungi and soil bacteria utilizing PCL as carbon or energy source were identified as Paecilomyces fumosoroseus KH27, Penicillium digitatum KH28, Fusarium solani KH29, Aspergillus sp. KH30 and Ochrobactrum anthropi KH31, respectively. Biodegradation test of PCL by the isolated strains showed that, P. digitatum KH28 exhibited the most PCL degrading activity at $27^\circ{C}$. However, at $37^\circ{C}$ O. anthropi KH31 showed higher degrading activity than the other soil microorganisms tested.

• Journal of Korean Society of Forest Science
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• v.101 no.4
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• pp.567-573
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• 2012

This study was carried out to examine the effect of soil amendment treatments [(organic fertilizer: 20 kg $tree^{-1}$; compound fertilizer+wood-char fertilizer: compound fertilizer 4 kg $tree^{-1}$+wood-char 2 kg $tree^{-1}$; lime fertilizer: 3 kg $tree^{-1}$; mixed fertilizer: compound fertilizer 1 kg $tree^{-1}$+organic fertilizer 10 kg $tree^{-1}$+wood-char 1 kg $tree^{-1}$; control (no fertilizer)] on flowering and fruit characteristics in chestnut (Castanea crenata S. et Z.) orchards in Jinju and Sancheong, Gyeongsangnam-do. Diameter of fruiting shoot increased generally after soil amendment treatments compared with the control, while number of leaf, female and male flowers were not affected by the treatments. Nut weight increased after soil amendment treatments in Jinju, but was not affected by the treatments in Sancheong. There was a positive correlation between soil pH (r=0.91) or exchangeable $Ca^{2+}$ (r=0.99) and nut weight in Jinju and a positive correlation (r=0.97) between organic carbon content and soluble solid concentration, while a negative correlation (r=-0.92) between exchangeable $Mg^{2+}$ and soluble solid concentration of nuts in Jinju. However, the nut weight and soluble solid concentration in Sancheong were not correlated with soil properties. The results indicate that the characteristics of flowering and nuts in chestnut orchards depend on soil properties after soil amendment treatments between regions which show better responses on poor sites than on good sites.

• Journal of Wetlands Research
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• v.26 no.2
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• pp.168-181
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• 2024

Constructed wetlands (CWs) deliver a range of ecosystem services, including the removal of contaminants, sequestration and storage of carbon, and enhancement of biodiversity. These services are facilitated through hydrological and ecological processes such as infiltration, adsorption, water retention, and evapotranspiration by plants and microorganisms. This study investigated the correlations between microbial populations, soil physicochemical properties, and treatment efficiency in a horizontal subsurface flow constructed wetland (HSSF CW) treating runoff from roads and parking lots. The methods employed included storm event monitoring, water quality analysis, soil sampling, soil quality parameter analysis, and microbial analysis. The facility achieved its highest pollutant removal efficiencies during the warm season (>15℃), with rates ranging from 33% to 74% for TSS, COD, TN, TP, and specific heavy metals including Fe, Zn, and Cd. Meanwhile, the highest removal efficiency was 35% for TOC during the cold season (≤15℃). These high removal rates can be attributed to sedimentation, adsorption, precipitation, plant uptake, and microbial transformations within the CW. Soil analysis revealed that the soil from HSSF CW had a soil organic carbon content 3.3 times higher than that of soil collected from a nearby landscape. Stoichiometric ratios of carbon (C), nitrogen (N), and phosphorus (P) in the inflow and outflow were recorded as C:N:P of 120:1.5:1 and 135.2:0.4:1, respectively, indicating an extremely low proportion of N and P compared to C, which may challenge microbial remediation efficiency. Additionally, microbial analyses indicated that the warm season was more conducive to microorganism growth, with higher abundance, richness, diversity, homogeneity, and evenness of the microbial community, as manifested in the biodiversity indices, compared to the cold season. Pollutants in stormwater runoff entering the HSSF CW fostered microbial growth, particularly for dominant phyla such as Proteobacteria, Actinobacteria, Acidobacteria, and Bacteroidetes, which have shown moderate to strong correlations with specific soil properties and changes in influent-effluent concentrations of water quality parameters.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.7
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• pp.1243-1252
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• 2000

The differential enhanced degradation of cis- and trans-1,3-D was observed in the previous two studies performed by several researchers. This study was initiated to investigate the involvement of microorganisms in the differential enhanced degradation of the chemicals. As expected, microorganisms were responsible for the enhanced degradation. A mixed bacterial culture capable of degrading 1,3-D was isolated from an enhanced soil sample collected from a site treated with 1,3-D. Similar to the enhanced soil, the mixed culture degraded trans-1,3-D faster than cis-1,3-D. This mixed culture could not utilize cis- and trans-1,3-D as a sole source of carbon for growth. Rather, a variety of second substrates were evaluated to stimulate the differential enhanced degradation of the two isomers. As a result, the mixed culture degraded cis- and trans-1,3-D only in the presence of a suitable second substrate. Therefore, it appeared that the degradation of cis- and trans-1,3-D was a cometabolic process. Second substrates that had the capacity to stimulate the degradation included soil leachate, tryptone, tryptophan, and alanine. Other substrates tested. including soil extract. glucose, yeast extract and indole, failed to stimulate the degradation of the two isomers. The mixed culture was composed of four morphologically distinctive colonies on L-agar plates.

• Korean Journal of Environmental Agriculture
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• v.17 no.1
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• pp.11-15
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• 1998

Carbofuran was incubated for four weeks in five types of paddy soil samples at $25^{\circ}C$. The soil samples prepared in the study were as follows : control soil, sterilized soil, 10% cellulose added soil, 10% cellulose and 1% ferrous sulfate added soil, and 10% cellulose and 1% magnesium sulfate added soil. The degradation rate of carbofuran was significantly decreased(p<0.05) in sterilized soil.The degradation rate of carbofuran was significantly decreased by addition of cellulose(p<0.05) in femous sulfate added soil and magnesium sulfate added soil(p<0.01).

• Korean Journal of Environmental Agriculture
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• v.30 no.1
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• pp.16-23
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• 2011

BACKGROUND: This study was conducted to investigate the effects of different organic treatments and a chemical fertilizer on the soil chemical, physical, and microbial properties in an organic pear orchard. METHODS AND RESULTS: Control was referred as a NPK chemical fertilizer (15N-9P-10K) and organic treatments included compost containing with oil cake, compost containing with humic acid, and compost containing with chitin substance. All treatments applied at rates equivalent to 200 g N per tree per year under the tree canopy in March 30 of 2008 and 2009. Soil bulk density, solid phase, liquid phase, and penetration resistance were not significantly different among the treatments. Organic treatment plots had greater organic matter, total nitrogen, potassium, and magnesium concentrations compared to control, and the nutrient concentrations were not consistently affected by the organic treatments. Microbial biomass nitrogen and carbon, dehydrogenase, acid-phosphatase, and chitinase activities overall increased from March to August. Organic treatments, especially compost containing with oil cake or chitin aicd, increased the microbial variables compared to control. CONCLUSION(s): All the organic treatments consistently stimulated soil biological activity. The consistent treatment effect, however, did not occur on the soil mineral nutrition as the trees actively taken up the nutrients during a growing season, which would have diminished treatment effects. Long-term study required for evaluating soil physical properties in a pear orchard.

• Korean Journal of Soil Science and Fertilizer
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• v.27 no.3
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• pp.149-157
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• 1994

The conditions for formation of allophane in volcanic ash soils in Cheju Island were investigated. Soils of toposequence distributed along the sourthern slope of Mt. Halla, and the major soil groups such as dark brown soils, very dark brown soils, black soils, and brown forest soils were colleted and analyzed for Al, Fe and Si extracted with solutions of pyrophosphate and oxalate. Mean annual temperature decreased $0.8^{\circ}C$ and mean annual precipitation increased 110mm with increase elevation of 100m. Organic carbon content increased and soil pH decreased with elevation, and the formation of allophane in soils formed a climosequence. Dark brown soils widely distributed in the northern and western coastal areas, where the mean annual precipitation ranged 1,240~1,420mm and the evaporation ranged 1,290~1,320mm, contained only small amounts of allophane and Al-humus complexes. For other soils, organic carbon content, pyrophosphate extractable Al, and $Al_p/Al_o$ were inversely correlated with $pH(CaCl_2)$. Allophane content showed close relationships wlth $pH(CaCl_2)$, and inverse relationships with organic carbon content and $Al_p/Al_o$.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.12
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• pp.1337-1346
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• 2006

Soil humin is the insoluble fraction of humic materials and play an important roles in the irreversible sorption of hydrophobic organic contaminants onto soil particles. However, there have been limited knowledge about the sorption and chemical properties of humin due to the difficulties in its separation from the inorganic matrix(mainly clays and oxides). In this study, de-ashed soil humins($Hu_1-Hu_6$) were isolated from a soil residues(Crude Hu) after removing alkali-soluble organic fractions followed by consecutive dissolution of the mineral matrix with 2%-HF for 2 hr. The humin samples were characterized by elemental analysis and $^{13}C$ NMR spectroscopic method and their sorption-desorption behavior for 1-naphthol were investigated from aqueous solution. The results were compared one another and that with peat humin. $^{13}C$ NMR spectra features indicate that the soil humin molecules are mainly made up of aliphatic carbons(>80% in total carbon) including carbohydrate, methylene chain. Freundlich sorption parameter, n was increased from 0.538 to 0.697 and organic carbon-normalized sorption coefficient(log $K_{OC}$) values also increased from 2.43 to 2.74 as inorganic matrix of the soil humin removed by HF de-ashing. The results suggest that inorganic phase in humin plays an important, indirect role in 1-naphthol sorption and the effects on the sorption non-linearity and intensity are analyzed by comparison between the results of soil humin and peat humin. Sorption-desorption hysteresis were also observed in all the humin samples and hysteresis index(HI) at low solute concentration($C_e$=0.1 mg/L) are in order of Peat humin(2.67)>De-ashed humin(0.74)>Crude Hu(0.59).

• Korean Journal of Environmental Agriculture
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• v.38 no.4
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• pp.262-268
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• 2019

BACKGROUND: To investigate mineralization characteristics of organic resources in the soil, five materials (rice straw, cow manure sawdust compost, microorganism compost, mixed oil-cake, and amino acid fertilizer) were treated according to the nitrogen content, and an indoor incubation experiment was conducted for 128 days. The results of this analysis were applied to determine the nitrogen mineralization pattern of these organic resources. METHODS AND RESULTS: During the constant temperature incubation period, the nitrogen net mineralization rate of the organic resources was the highest in the amino acid fertilizer with the highest nitrogen content, and the lowest in the rice straw with the lowest nitrogen content. A positive correlation (0.96) was observed between the potential nitrogen mineralization rate and total nitrogen content. The mineralization rate constant, k, was negatively correlated with the organic matter (-0.96) and carbon content (-0.97). The nitrogen mineralization rate during the first cropping season, as estimated by the model, was 6.6%, 11.6%, 30.9%, 70.7%, and 81.0% for the rice straw, the cow manure sawdust compost, the microorganism compost, the mixed oil-cake, and the amino acid fertilizer, respectively. CONCLUSION: The nitrogen mineralization rate varies depending on the type of organic resources or the nitrogen content; thus, it can be used as an index for determining the nitrogen supply characteristics of the organic resource. Organic resources such as compost with low nitrogen content or those undergoing fermentation contain organic nitrogen. Organic nitrogen is stabilized during the composting process. Therefore, as the nitrogen mineralization rate of these resources is lower than that of non-fermented organic resources, it is desirable to use the fermented organic materials only to improve soil physical properties rather than to supply nutrients for the required amount of fertilizer.