• Magazine of the Korean Society of Agricultural Engineers
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• v.39 no.3
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• pp.96-107
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• 1997

This study was carried out to examine the physicochemical characteristics of dredged soils in reservoirs. Surveys and analyses of basic materials were made on 241 of 2,328 reservoirs in Chonbuk province through 2 years from December 1994 to November 1996. The results of this study are summarized as follows : 1. Soils were classified as 15 types according to physical properties, and some soils contain comparatively high percentage of sand and gravel. Considering only soil textures, useful and economical soils as aggregate are approximately 25% in all, and the other soils are arable for farm planting. 2. The results of chemical analyses of soils showed on the average 5.9 in pH, 1.lmmhos/cm in ECe, 14.6me/l00g in CEC, 460.0ppm in T-N, 119.0ppm in T-P, 264.9ppm in K, 134.2ppm in Na, l,335.0ppm in Ca, 575.9ppm in Mg, 486.Sppm in Fe, 57.7ppm in Mn, 3.3ppm in Cu, 21.9ppm in Zn, 0.49ppm in As, 0.34ppm in Cd, 0.O3ppm in Hg, 1.7% in OM, respectively. 3. General chemical components, heavy metals, organic matter contents were analyzed as similar to tlie mean values of common soils, therefore it was considered to be no significant effects on crop growth in the chemical properties. 4. Accodingly, the physicochemical characteristics of soils ought to be analyzed accurately before dredging for effective using of dredged soils. And it will be more effective, if the dredged soils are used with proper balance among each content of components with considering to the physicochemical properties of common soils.

• Journal of Soil and Groundwater Environment
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• v.16 no.1
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• pp.51-61
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• 2011

Germination tests were conducted to determine the practical concentration levels at which plants can reproduce naturally during the phytoremediation of soils contaminated with a high concentration of petroleum hydrocarbons and heavy metals. The effects of humic acids on plant growth and soil physicochemical properties were also investigated. The results show that phytoremediation can be applied in soils contaminated by multiple contaminants at the former soil contamination potential level of Korean soil quality standards considering successful natural reproduction. It was observed that germination rates of Helianthus annuus and Festuca arundinacea were high after all treatments, and transplantation was more appropriate for Phragmites communis in phytoremediation. Humic acids had a positive effect on the growth of both aboveground and belowground biomass of herbaceous plants. Growth inhibition by multiple contaminants is more severe in the case of aboveground biomass. Germination and growth tests suggest that Helianthus annuus is a suitable phytoremediation plant for soils contaminated with a high concentration of petroleum hydrocarbons and heavy metals. The addition of humic acids also caused changes in the physicochemical properties of contaminated soils. An increase in the carbon and nitrogen content due to the addition of humic acids and a correlation between cation exchange capacity(CEC) and the organic matter content were observed.

• Journal of the Korean Institute of Landscape Architecture
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• v.32 no.6 s.107
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• pp.95-102
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• 2005

This study was carried out to find out the heavy metal contents and the physico-chemical properties for the improvement of dredged soils which widely exist in lowlands of Korea. At first all the average heavy metal contents were close to background level and were much lower than concern level of the Soil Environment Conservation Act of Korea. And the results of physical analyses of soils showed on the average $2.46\~2.74 Mg/m^3$ in Particle density, $0.45\~2.45 kg/kg$ in soil water contents, $0.34\~0.90 Mg/m^3$ in bulk density, $0.67\~0.87m^3/m^3$ in porosity, $2.18\times10^{-5}\~1.20\times10^{-8} m/s$ in saturated hydraulic conductivity, R0.12\~0.65 m^3/m^3$ in available water contents. Finally the results of chemical analyses of soils showed on the average $6.5\~8.2\;in\; pH,\;5\~48 g/kg\;in\; OM,\;0.48\~4.51g/kg\;in\;T-N,\;19\~25mg/kg$ in available phosphate, $0.28\~11.80 dS/m\;in\;EC,\;8.7\~38.1cmol/kg$ in CEC, respectively Accordingly, the physicochemical properties of soils ought to be analyzed accurately before dredging for effective using of dredged soils. And it will be more effective, if the dredged soils are used with proper balance among each content of components with consideration to the physicochemical properties of common soils.

• Journal of Soil and Groundwater Environment
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• v.20 no.4
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• pp.83-89
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• 2015

Soil samples collected in an area of Gahak Mine were investigated for the characterization of mineralogical and physicochemical properties of contaminants in soils. It is found that soils in the study area are contaminated by lead (Pb), copper (Cu), zinc (Zn), cadmium (Cd), in which their concentrations are 595.3 mg/kg, 184.9 mg/kg, 712.8 mg/kg, and 10.64 mg/kg, respectively. All the concentrations exceed the concern criteria of Korean standard. Upon distribution patterns of metals identified by the sequential extraction procedure, our results show that more than 50% of metals are found as a residual type, and 30% are accounted for the association of Fe/Mn oxides. Interestingly, XRD results show that minium (Pb₃O₄) and cuprite (Cu₂O) are identified in the soil samples, suggesting that the sources of the contaminants for Pb and Cu are these minerals. In SEM images, tens of µm of Pb oxides and Pb silicate-minerals are observed. We, therefore, note that the contamination of metals in the study area results from the direct influx and disturbance of tailings. Our findings indicate that the characterization of physicochemical and mineralogical properties of contaminated soils is a critical factor and plays an important role in optimizing recovery treatments of soils contaminated in mine development areas.

• The Plant Pathology Journal
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• v.16 no.5
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• pp.283-285
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• 2000

Two field tests were conducted in 1995 to examine the effects of composts and soil amendments on physicochemical properties of soil in relation to Phytophthora root and crown rot of bell pepper. Chitosan, crab shell waste, humate, sewage sludge-yard trimmings, and wood chips were applied to test plots, some of which affected the levels of P, K, Mg, pH, and H. Physicochemical properties were not related with disease incidence, but percent organic matter, estimated nitrogen release, K, and Mg were correlated with total microbial activity. The elements K and Mg were especially responsible for the increased soil microbial activity that could affect development of root and crown rot of pepper.

• Journal of Environmental Science International
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• v.27 no.7
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• pp.561-575
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• 2018

Agricultural soils around springwaters heavily affected by pesticide run-off and around wells considering the regional characteristics were collected at 24 stations in Jeju Island, and the physicochemical properties and adsorption and leaching characteristics of four nonionic pesticides (diazinon, fenitrothion, alachlor, and metalaxyl) were investigated. The values of the major soil factors affecting the adsorption and leaching of pesticides, namely, soil pH($H_2O$), organic matter content, and cation exchange capacity (CEC), were in the range of 4.64 ~ 8.30, 0.9 ~ 13.1% and 12.7 ~ 31.7 meq/100 g, respectively. The Freundlich constant, $K_F$ value, which gives a measure of the adsorption capacity, decreased in the order of fenitrothion > diazinon > alachlor > metalaxyl, which was identical to their lower water solubility. Among the collected soils, the $K_F$ value was very highly correlated with organic matter content ($r^2=0.800{\sim}0.876$) and CEC ($r^2=0.715{\sim}0.825$) and showed a high correlation with clay content ($r^2=0.473{\sim}0.575$) and soil pH($H_2O$) ($r^2=0.401{\sim}0.452$). The leaching of pesticides in the soil column showed a reverse relationhip with their adsorption in soils, i.e., the pesticides leached more quickly for the soils with lower values of organic matter content and CEC among the soils and for the pesticides with higher water solubility.

• Korean Journal of Soil Science and Fertilizer
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• v.42 no.2
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• pp.98-102
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• 2009

Various physical properties of soils were investigated in the areas where organic farming had been practiced widely, for upland fields. The investigations were also conducted in the nearby fields under conventional to find out the influence of organic farming on the physical properties of soils. The investigated properties involved bulk density, hardness, shearing resistance, friction resistance, sinking depth of small rectangular board, water stable aggregates and the depth of soil available to plants. By and large, the practice of organic farming tended to improve all of the physical properties soils, investigated in upland soils. However, in case of water stable soil aggregates in upland soils, the reverse was previous data; in those soils water stable soil aggregates were less under organic farming. It was suspected that this might be due to intensive application of the organic materials with high C/N ratio like wood chips and wood bark. The contents of OM, Av. P2O5, and Ex. cations were higher in organic farming than those of nearby fields under conventional, due to heavy organic matter application. From the results, It could be concluded that soils under organic farming were looser and softer than those under conventional as shown by lower bulk density and hardness, but that the effect of organic farming on water stable aggregates were low.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.4
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• pp.545-550
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• 2011

Urea intercalated into montmorillonite (MT) exhibits remarkably enhanced N use efficiency, maintaining its fast effectiveness. This study dealt with the release property of urea from metal-urea-clay hybrid with MT (MUCH) under continuous-flow conditions and the cumulative impacts of its successive application on physicochemical properties of soils. Releases of urea were completed within 4 hrs under continuous-flow condition regardless of the types and the leaching solutions. However, urea release property was significantly affected by both the form of fertilizer and the presence of electrolytes in solution. The fast release property of urea from MUCH in continuous-flow condition was not significantly affected by soil properties such as soil pH and soil texture. In addition, its successive application did not lead to any noticeable change in soil physicochemical properties, water stable aggregate rate, water holding capacity and cation exchange capacity in both sandy loam and clay loam soils. Therefore, this study strongly supported that urea intercalated into MT could be applied as fast-effective N fertilizer, in particular for additional N supply.

• Journal of Environmental Science International
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• v.19 no.2
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• pp.217-227
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• 2010

This paper was studied $CO_2$ respiration rate with physicochemical properties of soils at wetland, paddy field and forest in Nongju-ri, Haeryong-myeon, Suncheon city, Jeollanam-do. Soil temperature and $CO_2$ respiration rate were measured at the field, and soil pH, moisture and soil organic carbon were analyzed in laboratory. Field monitoring was conducted at 6 points (W3, W7, W13, W17, W23, W27) for wetland, 3 points (P1, P2, P3) for paddy field and 3 points (F1, F2, F3) for forest in 10 January 2009. $CO_2$ concentrations in chamber were measured 352~382 ppm for wetland, 364~382 ppm for paddy field and 379~390 ppm for forest, and the average values were 370 ppm, 370 ppm and 385 ppm, respectively. $CO_2$ respiration rates of soils were measured $-73{\sim}44\;mg/m^2/hr$ for wetland, $-74{\sim}24\;mg/m^2/hr$ for paddy field and $-55{\sim}106\;mg/m^2/hr$ for forest, and the average values were $-8\;mg/m^2/hr$, $-25\;mg/m^2/hr$ and $38\;mg/m^2/hr$. $CO_2$ was uptake from air to soil in wetland and paddy field, but it was emission from soil to air in forest. $CO_2$ respiration rate function in uptake condition increased exponential and linear as soil temperature and soil organic carbon. But, it in emission condition decreased linear as soil temperature and soil organic carbon. $CO_2$ respiration rate function in wetland decreased linear as soil moisture, but its in paddy and forest increased linear as soil moisture. $CO_2$ respiration rate function in all sites increased linear as soil pH, and increasing rate at forest was highest.

• Korean Journal of Soil Science and Fertilizer
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• v.19 no.3
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• pp.251-268
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• 1986

Selecting a site for the safe disposal of radioactive waste requires the evaluation of a wide range of geologic, mineralogic, hydrologic, and physicochemical properties. Although highly diverse, these properties are in fact interrelated. Site requirements are also diverse because they are influenced by the nature of the radionuclides in the waste, for example, their half-lives, specific energy, and chemistry. A fundamental consideration in site selection is the mineralogy of the host rock, and one of the most ubiquitous mineral groups is clay minerals. Clays and clay minerals as in situ lithologic components and engineered barriers may playa significant role in retarding the migration of radionuclides. Their high sorptivity, longevity (stability), low permeability, and other physical factors should make them a very effective retainer of most radionuclides in nuclear wastes. There are, however, some unanswered questions. For example, how will their longevity and physicochemical properties be influenced by such factors as radionuclide concentration, radiation intensity, elevated temperatures, changes in redox condition, pH, and formation fluids for extended periods of time? Understanding of mechanisms affecting clay mineral-radionuclide interactions under prevailing geochemical conditions is important; however, the utilization of experimental geochemical information related to physicochemical properties of clays and clay-bearing materials with geohydrologic models presents a uniquely challenging problem in that many assessments have to be based on model predictions rather than on experiments. These are high-priority research investigations that need to be addressed before complete reliance for disposal area performance is made on clays and clay minerals.