• KSBB Journal
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• v.28 no.5
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• pp.275-281
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• 2013

Soil microbial community analysis of farmland soil sprayed with lye in order to use fertilizer in Nigeria was performed. As a control, two kinds of soils not sprayed with lye, located in Eungo and Lagos with general practice in agriculture was selected. Soil sprayed with lye was pH 8.25 through alkalization reaction, while the other soil samples were pH 6.22 and 5.94. Substrate utilization and species diversity index of soil sprayed with lye were low than that of the other soils with the analysis of Biolog ecoplate. As a result of principal component analysis, the relationship between three samples was low. Microbial community analysis was performed by DGGE and most of them were soil uncultured bacterium. Especially, Uncultured Acidobacteria and Uncultured Methylocystis sp., which had been isolated from the rhizosphere of soybean grown in that site were discovered in the soil sprayed with lye.

• Korean Journal of Veterinary Research
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• v.22 no.2
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• pp.253-258
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• 1982

The frequent finding of soil contamination by dogs' feces are remarkable, and such soil contamination may be public health problem. Of 608 samples, 30(4.9%) were positive for nematode ova. Ten paint 3% of sail samples from parks and 7.9% from footpaths were found to contain nematode eggs. Of the helminth eggs detected, eggs of Toxocara spp. were the most commonly encountered, and mostly from the soil of footpaths. No eggs were recovered from the soil of school yards; the level of soil contamination was low in public play areas. Egg recovery rate of the soil to dogs' feces collected from footpaths was approximately 1:5. And the larvae demonstrated from the soil in the present study were nematode larvae, mainly recovered from parks.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 1999.10c
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• pp.606-611
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• 1999

Recently , the hydraulic fill method is commonly used in many reclamation projects due to lack of fill materialss. The method of hydraulic fill i recalmation is executed by transporting the mixture of water -soil particles into a relcaimed land through dredging pipes, then the dredged soil particels settle down in thewater orflow over an out flow weir with the water. The amount of the volume reductions of dredged soil is considered the sum of the overall settlement by descication shrinkage and self-weigth consolidation and the loss of soil particles flow over a weir. In the present study, hydrometer analysis was performed with the soil samples obtained bofore and after dredging to estimate the amount of soil particles residual at reclaimed area and the loss of soil particles , then it was suggested the method of determining the loss ratio of dredged soils from the tests results. The hydrometer analysis of in-situ soil samples showed that the loss ratio of dredged soils is lowest at the nearest point to dredge pipe and highest at the nearest point of out flow weir.

• Geomechanics and Engineering
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• v.4 no.1
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• pp.55-65
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• 2012

This paper presents the results of an experimental study on the effect of suction on compressibility and shear behaviour of unsaturated silty soil under various types of loading. A series of laboratory experiments were conducted in a double-walled triaxial cell on samples of a compacted silty soil. In the experiments the soil samples were subjected to isotropic consolidation followed by unloading and subsequent reloading under constant suction and prescribed overconsolidated ratio. The experimental results are presented in the context of an elasto-plastic model for unsaturated soil. The effects of suction on mechanical behaviour of unsaturated silty soil are presented and discussed. It is shown that increasing suction affects the shear behaviour of unsaturated soils, but there is a limit beyond which, further increase in suction will not result in any significant change in the behaviour.

• The Korean Journal of Pesticide Science
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• v.9 no.4
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• pp.316-329
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• 2005

Mobility of pesticides can be occurred by run-off and leachate or soil erosion. It is one of the most important factors for environmental contamination, particularly in steep sloped-land as Gangwon alpine region. In this study, the mobility of seven pesticides in different slopes and soil textures was investigated by simulated rainfall under controlled conditions. Simulated rainfall subjected to 60 mm $hr^{-1}$ was treated using rainfall simulator after 12 hr of pesticide treatment. Amounts of the pesticides were measured in run-off and leachate samples. The soil samples collected after rainfall from upper and lower parts and three different depths of sloped-plot were also analyzed. At result, all pesticides from the un-off samples collected from Taebaek(silty clay loam) and Heongseong(sandy loam) soils were detected maximum 96% within 60 minutes after first collection except carbendazim and cypermethrin which have the lowest water solubilities. From the leachate samples, a similar pattern was shown as run-off samples but amount of pesticides was lower than those of run-off samples. In soil samples, the order of the amount of pesticide residues was $0{\sim}5$ > $5{\sim}10$ > $10{\sim}15$ cm of soil depth and no pattern was shown in upper and lower, and different slopes. Comparing to mobility of pesticides in water and soil samples, pesticides in soil samples were higher than those of water samples in Taebaek soil. However, the results using Heongseong soils were in contrast to those of Taebaek soil. These results revealed that mobility of pesticides can be dependant mainly on soil textures and physicochemical properties of pesticides. Therefore, it can be suggested that selection of pesticides should be considered for soil texture and properties of pesticide in the alpine and sloped-land.

• Economic and Environmental Geology
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• v.48 no.3
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• pp.213-219
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• 2015

Samples from soils and crops were collected and analyzed in order to investigate the interactions of selenium among rocks, soils, and crops by hydrothermal alteration near epithermal mines in the region of Mio-san, Haenam. Soil samples included 6 samples each from mountain and farm area and compositional minerals and their contents were analyzed by water content, pH, ICP, XRD, XRF. Crop samples from onion and scallion were analyzed for chemical composition to elucidate the relationship with soils. Results from XRD analysis for soil samples showed that major compositional minerals are qualtz and feldspar, and illite, chlorite, hematite formed by hydrothermal alteration were included on a small scale. The pH ranges of soil samples from mountain and farm were measured at 4.6~4.9 and 5.2~6.7, respectively. The higher pH in farm soils may result from fertilization during agricultural activities. Results from ICP analysis showed that, compared to soil samples from mountain area with no potassium and calcium, significant amount of K and Ca were detected in soil samples from farms which is affected by fertilization. In a similar manner, potassium and calcium were absorbed and detected in crop samples at relatively high concentrations (116.89~169.79 ppm for K and 20.18~32.29 ppm for Ca). While the selenium contents in soil samples ranged from 18.35 ppb to 70.31 ppb which showed no significant difference, high concentrations of selenium were detected in onion (119.48~179.50 ppb) and scallion (146.65 ppb). These difference in enrichment for each element may result from the distinctive adsorption characteristics depending on crops.

• Korean Journal of Soil Science and Fertilizer
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• v.50 no.2
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• pp.100-105
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• 2017

Various methods for assessing soil total nitrogen (TN) and inorganic N content have been developed to manage nutrient and to understand N cycle in soil. This paper address the technical procedures in arable soil samples to conduct soil sampling, sample preparation, and measuring total N and inorganic N. Among various methods for measuring soil total nitrogen contents, Kjeldahl distillation and Indophenol blue method have widely used due to reliability and economic advances. Also, two methods can analyze more samples at the same time compared with other nitrogen measuring methods. For evaluating inorganic N content, mainly in forms of nitrate-N ($NO_3{^-}-N$) and ammonium-N ($NH_4{^+}-N$), extraction with a single reagent such as 2M KCl has been employed, followed by Kjeldahl distillation or indophenol blue methods.

• Journal of The Korean Society of Grassland and Forage Science
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• v.20 no.2
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• pp.109-114
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• 2000

The aim of present research was to know Cd availability. As a first report of this work, we present some results of analysing soil Cd and Cu contents on a part of Burgundy in France. Soil samples were collected from surface-ploughed layer in fields across the southern part of the Yonne district, Burgundy, France. From the first extractable Cd content on a ratio (soil : EDTA =1:10), the soil Cd values on Carixien soil series decreased to a-third or to a-fourth of those Cd values on a lower ratio (soil : EDTA = 15). While the extractable Cd of the soil samples on Sols marron soil series decreased in a smaller extent. The changes of mixing ratio from 150 (soil : EDTA) to 1:10 and to 1:5 (soil : EDTA) had decreased the extractable Cu contents. But the range of the decrease was not so large as that of Cd contents. Soils on some soil series were a half (Carixien) or two-thirds level (Dombrien, Aubes) when comparing the extractable Cu content on 1:5 ratio to the content on 150 ratio. The absorbance for Cu analyses of soils on Carixien, Terres noires, Sols marron soil series varied in larger extent (expressed on standard deviation for 6 values) than that of soils on Dombrien, Aubes soil series.

• Journal of Conservation Science
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• v.37 no.4
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• pp.357-361
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• 2021

In order to determine the changes in microbial community due to termites, soil microorganisms surrounding the termites were investigated. First, bacterial communities from soil with termites collected at Seonamsa temple, Suncheon city, Korea were compared by next-generation sequencing (NGS, Illumina Miseq). The bacterial composition of soil from Daeungjeon without termites and the soil from Josadang, Palsangjeon, and Samjeon with termites were compared. Next, the bacterial composition of these soils was also compared with that of humus soil cultured with termites. A total high-quality sequences of 71,942 and 72,429 reads were identified in Seonamsa temple's soil and humus soil, respectively. The dominant phyla in the collected Seonamsa temple's soil were Proteobacteria (27%), Firmicutes (24%) and Actinobacteria (21%), whereas those in the humus soil were Bacteriodetes (56%) and Proteobacteria (37%). Using a two-dimensional plot to explain the principal coordinate analysis of operational taxonomic unit compositions of the soil samples, it was confirmed that the samples were divided into soil with and without termites, and it was especially confirmed that the Proteobacteria phylum was increased in humus soil with termites than in humus soil without termites.

• Geomechanics and Engineering
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• v.23 no.3
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• pp.227-244
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• 2020

Earthen structures have an excellent bioclimatic performance, but they are vulnerable against earthquakes. In order to investigate the edification process and costs, a full-scale rammed soil house was constructed in 2004. In 2016-2019, it was studied its seismic damage, durability and degradation process. During 2004-2016, the house presented a relatively good seismic performance (M_w=5.6-6.4). The damaged cover contributed in the fast deterioration of walls. In 2018 it was observed a partial collapse of one wall due to recent seismicity (M_w=5.6-6.1). The 15-year-old samples presented a reduced compressive strength (0.040 MPa) and a minimum moisture (1.38%). It is estimated that the existing house has approximately a remaining 20% of compressive strength with a degradation of about 5.4% (0.0109 MPa) per year (considering a time frame of 15 years) if compared to the new soil samples (0.2028 MPa, 3.52% of moisture). This correlation between moisture and compressive strength degradation was compared with the study of new soil samples at the same construction site and compared against the extracted samples from the 15-year-old house. At 7-14-days, the specimens presented a similar compressive strength as the degraded ones, but different moisture. Conversely, the 60-days specimens shown almost five times more strength as the existing samples for a similar moisture. It was observed in new rammed soil that the lower the water content, the higher the compressive/shear strength.