• Korean Journal of Soil Science and Fertilizer
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• v.44 no.5
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• pp.773-778
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• 2011

Long-term continuous application of livestock by-products to agricultural land may adversely affect the soil characteristics and the crop yield. Five year term study from 2007 was carried out to assess the effects of repeated application of low-concentration swine slurry on soil chemical properties including phosphate and heavy metal contents and yield of tomato (Lycopersicon esculentum) and cucumber (Cucumis sativus L.) in a greenhouse. Treatments were conventional chemical fertilizers and three application rates of low-concentration swine slurry (Slurry composting and biofiltration, SCB): 50%, 100%, and 200% of recommended nitrogen fertilization. For swine slurry treatment of 50% nitrogen, deficient nitrogen was supplemented with urea fertilizer. The soil phosphorus and heavy metal contents after five year continuous application of swine slurry were not significantly higher than those of chemical fertilizer use. Repeated application of the swine slurry alone for five years resulted in relatively high soil exchangeable potassium and sodium compared with chemical fertilizer treatment. Contents of heavy metals in leaves of tomato and cucumber did not show significant difference among treatments. Yields of the crops for the swine slurry were not significantly different from that of chemical fertilizer. The results imply that continuous application of the swine slurry may not influence levels of soil phosphate and trace elements in greenhouse soils but could accumulate potassium and sodium in the soil.

• Korean Journal of Agricultural and Forest Meteorology
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• v.4 no.1
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• pp.49-57
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• 2002

This study was conducted to find out buffer capacities of forest soils by the treatment of simulated acid rain(SAR) of four forests(Q. spp., P. rigida, P. koraiensis, L. leptolepis) in Kyunghee university's practice forest. All soils of each forest stand were treated by simulated acid rain at the level of pH 3.0, 4.0, 5.0 respectively. The result obtained from this study can be summarized as follows: Soil pH was measured by soil depth of each forest stand. The deeper soil depth was, the higher soil pH was. Also it was appeared that base saturation of sample soils was the highest as 17.42% in P. rigida stand and cation exchange capacity(C.E.C) was the highest as 29.87 me/100 g in Q. spp. stand. for responses of soil leachates to acidification treatment with pH 3.0 simulated acid rain(SAR), as simulated acid rain(SAR)-input was increased, pH value of soil leachates appeared high temporarily, but soon pH value of soil leachates had been low gradually. At the rest of pH 4.0, pH 5.0 treatment, pH value of soil leachates was high proportionably. The amounts of TBC of primary stage had a difference as pH level of simulated acid rain and forest stands. But as simulated acid rain(SAR)-input was increased. Amount of TBC was diminished. Also the amounts of TBC of primary stage in acidification treatment with pH 3.0, 4.0 simulated acid rain(SAR) was higher that of acidification treatment with pH 5.0 simulated acid rain(SAR). These trend showed obvious difference at low soil acidity and high TBC. The amounts of activity Al of primary stage appeared high as increasing the input acidity of simulated acid rain(SAR). Also, by soil depth, the amounts of Activity Al was different between A layer(0-15 cm) and AB layer(0-30 cm). There was considerable the correlation between simulated acid rain-input and activity Al change. But this was oppositional trend in soil leachates of pH 4.0, 5.0 treatment and total base cations(TBC).

• Journal of the Korea Organic Resources Recycling Association
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• v.9 no.2
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• pp.71-76
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• 2001

Recently, sludge disposal becomes one of the most serious environmental problems. Because the landfilling and ocean dumping of sludge materials will be prohibited in the near future, the proper treatment?disposal methods should be investigated. Also, oyster shells, piled at the coast, cause adverse effects in coastal fishery, public water surface, natural landscape, public health and so on. Thus, the purpose of this study is to evaluate the dissolution characteristic of metal compounds during soil application experiment using sewage treatment sludge mixed with oyster shells. The dissolution experiment conducted 100days under artificial rainfall and farming soil, mixed with sewage treatment sludge and oyster shells, was put into the pots(approx. 0.5L). The results from dissolution experiment as follows. 1. K, Na was $5{\sim}20mg/{\ell}$, and Ca was less than $90mg/{\ell}$. 2. Heavy metals such as Cd, Cu, As, Pb, Cr, Hg are dissoluted far less than the soil pollution guideline. The application of sewage sludge mixed with oyster shells increases pH(soil acidity)and buffer capacity(CEC) of farming soil, and heavy metals are thought to be attached to soil as insoluble forms.

• Journal of Soil and Groundwater Environment
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• v.14 no.5
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• pp.62-70
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• 2009

A field soil highly contaminated with petroleum hydrocarbons (JP-8 and diesel fuels) was employed for its remediation by a lab-scale thermal desorption process. The soil was collected in the vicinity of an underground storage tank in a closed military base and its contamination level was as high as 4,476 ppm as total petroleum hydrocarbon (TPH). A lab scale directly-heated low temperature thermal desorption (LTTD) system of 10-L capacity was developed and operated for the thermal treatment of TPH contaminated soils in this study. The desired operation temperature was found to be approximately $200-300^{\circ}C$ from the thermal gravimetric analysis of the contaminated field soils. The removal efficiencies higher than 90% were achieved by the LTTD treatment at $200^{\circ}C$ for 10 min as well as at $300^{\circ}C$ for 5 min. As the water content in the soils increased and therefore they were likely to be present as lumps, the removal efficiency noticeably decreased, indicating that a pre-treatment such as field drying should be required. The analysis of physical and chemical properties of soils before and after the LTTD treatment demonstrated that no significant changes occurred during the thermal treatment, supporting no needs for additional post-treatments for the soils treated by LTTD. The results presented in this study are expected to provide useful information for the field application and verification of LTTD for the highly contaminated geo-environment.

• Weed & Turfgrass Science
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• v.5 no.3
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• pp.165-169
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• 2016

To establish the soil management system for the efficient sod production, survey on the growth of zoysiagrass by different soil managements was conducted in repeated cultivation field with regard to soil physical properties. Soils were subjected to four types of management methods, which include (1) rolling (2) topdressing (3) topdressing + rolling (4) topdressing + tillage + rolling. The topdressing + tillage + rolling treatment significantly ameliorated soil physical properties such as bulk density, porosity and solid phase as compared to rolling and topdressing + rolling treatments, and was not significantly different from the topdressing treatment. Further growth and density of zoysiagrass except for the root dry weight in topdressing + tillage + rolling treatment were significantly higher than that only in rolling treatment. Topdressing + tillage + rolling treatment significantly increased the number of shoot as compared to the other treatments. Therefore, combined topdressing and tillage soil management practice should be conducted for the production of zoysiagrass in repeated cultivation field.

• Korean Journal of Soil Science and Fertilizer
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• v.36 no.4
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• pp.218-224
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• 2003

Magnesium hydroxide, which recently registered as a Mg fertilizer, is greatly different from magnesium sulfate in its solubility and effect on soil pH. In this study, the effects of magnesium hydroxide and magnesium sulfate on growth of chinese cabbage were compared at the application rate of $300kg\;MgO\;ha^{-1}$ in a Gyeongsan clay loam soil. Although magnesium hydroxide was effective in increasing number of leaf and fresh weight, overall effects of magnesium hydroxide and magnesium sulfate on the growth of chinese cabbage were not significantly different ($p{\leq}0.05$). Comparing the two magnesium fertilizer treatments, magnesium content of chinese cabbage was relatively higher in the magnesium sulfate treatment in the early stage of growth, but it was higher in the magnesium hydroxide treatment at harvest. Contents of Ca, P, and K in chinese cabbage were relatively higher in the magnesium hydroxide treatment than those in magnesium sulfate treatment. But, the differences in nutrient uptakes by chinese cabbage between the treatments were not significant ($p{\leq}0.05$). Therefore, magnesium hydroxide is expected to be used with nearly the same effects on crops as magnesium sulfate at the same application rate of Mg. Soil pH in the treatment of magnesium sulfate was lower than that of control treatment, but magnesium hydroxide could increase pH. Magnesium hydroxide can be used preferentially in acid and/or sandy soils, where magnesium sulfate can induce further soil acidification and leaching loss of Mg is often a severe problem.

• Korean Journal of Environmental Agriculture
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• v.11 no.2
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• pp.109-115
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• 1992

In order to investigate waether soil microorganism prefer diazinon to humic substances as their substate, the growth of soil bacteria and the activities of monooxygenase and ${\alpha}-,{\beta}-esterase$ were measured after treatment of diazinon and humic substances in defined medium at $30{\pm}1^{\circ}C$. Also, the degradation rate of diazinon was determined by addition of humic substances to the medium. The number of soil bacteria was increased from 1 day and 3 days after the treatment with humic substances and diazinon, respectively. And it showed about 1.5 times more with humic substances than diazinon at 10 days. Monooxygenase(MO) activity with the treatment of humic substances was higher than diazinon until 3 days after treatment in the order of HA > FA > humin. Esterase(ES) activity with the treament of humin and HA was higher than dizainon from 5 dyas, but FA was much similar to diazinon. The degradation rate of diazinon showed more persistancy by addition of humic substances ; 51.4% with humin treatment, 58.9% with HA, 62.4% with FA and 71.9% in control at 10 days after treatment. Therefore, as soil microorganisms perfer humic substances to diazinon, the degreadation rate of diazinon might be delayed by addition of humic stbstances in submerged soil.

• Textile Coloration and Finishing
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• v.29 no.4
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• pp.181-194
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• 2017

The biodegradability of polylactic acid(PLA) fabrics was evaluated by two methods: enzyme and soil degradation. Three different enzymes were selected to evaluate. Degradation times were measured at optimal enzyme treatment conditions. Biodegradation by enzymatic hydrolysis was compared with soil degradation. As a result, biodegradation created cracks on the fiber surface, which led to fiber thickening and shortening. In addition, new peak was observed at $18.5^{\circ}$ by degradation. Moreover, cracks indicating biofragmentation were confirmed by enzyme and soil degradation. By enzyme and soil degradation, the weight loss of PLA fabrics was occurred, there through, the tensile strength decreased about 25% by enzyme hydrolysis when 21 days after, and 21.67% by soil degradation when 60 days after. Furthermore, the biodegradability of PLA fabrics by enzymatic and soil degradation was investigated and enzymatic degradation was found to be superior to soil degradation of PLA fabrics. Among the three enzymes evaluated for enzymatic degradation, alcalase was the most efficient enzymes. This study established the mechanism of biodegradation of PLA nonwovens, which might prove useful in the textile industry.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2004.04a
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• pp.239-242
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• 2004

Pilot-scale soil washing facility was developed and operation condition was determined in order to remediate a soil contaminated with As, Ni and Zn. Soil washing facility is composed of soil particle separation, soil washing and wastewater treatment process. Both oxyanionic As and cationic Ni and Zn were effciently removed using HCl rather 0than H$_2$SO$_4$ and H$_2$PO$_4$. This is why oxyanion and cation metals can be extracted simultaneously from the contaminated soil in acidic solution. Further, the contaminated soils include calcite and then demand much acidity, that is consumption of acid solution. Fine particles are enriched with contaminants, and coarse particles are removed effectively rather than fine particles. As, Ni and Zn are strongly associated with minerals, and then the residence time should be increased for a reaction with washing solution.

• Korean Journal of Soil Science and Fertilizer
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• v.50 no.3
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• pp.187-194
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• 2017

This study was conducted to investigate rice yield and soil chemical properties affected by incorporation levels of green barley (GB) and hairy vetch (HV). The GB and HV were applied to the pots at 500, 1,000, 1,500, and $2,000kg\;10^{-1}$ (GB500, GB1000, GB1500, GB2000, HV500, HV1000, HV1500, and HV2000, respectively), and inorganic fertilizer ($N-P-K=9-4.5-5.7kg\;10a^{-1}$) treatment as control. After rice harvesting, chemical properties of soil such as pH, OM, T-N, and available $P_2O_5$ in GB and HV treated treatments were improved over those in Control treatment. The rice yield ranged from 433 to $512kg\;10a^{-1}$ for GB treatments and 490 to $532kg\;10a^{-1}$ for HV treatments, indicating that rice yield was affected by incorporation levels of GB and HV. The rice yields in GB2000, HV1000, HV1500 and HV2000 treatments increased by 3.3, 3.1, 6.4 and 7.4% compared with Control treatment, respectively. Therefore, minimum incorporation level of GB and HV for increasing rice yield was $2,000kg\;10a^{-1}$ of GB and $1,000kg\;10a^{-1}$ of HV.