• Journal of Climate Change Research
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• v.6 no.3
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• pp.249-256
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• 2015

This study was conducted to investigate the effects of different levels and types of nitrogen fertilizer on seedlings and soil chemical properties in a semi-arid area, Mongolia. 2-year-old Populus sibirica and 4-year-old Ulmus pumila seedlings were planted in May 2014. Six treatments with three levels of nitrogen (low-level: urea $5g\;tree^{-1}$; medium-level: urea $15g\;tree^{-1}$, ammonium sulfate $33g\;tree^{-1}$, urea $15g\;tree^{-1}$ with potassium phosphate $10g\;tree^{-1}$; high-level: urea $30g\;tree^{-1}$) were applied and for the medium-level of nitrogen, different types of fertilizer were treated. Survival rate, root collar diameter (RCD) growth rate, leaf nitrogen concentration of seedlings, and soil chemical properties were determined in August 2014. The seedling survival rate of both species decreased as the level of nitrogen increased. This result can be explained by water stress caused by nitrogen fertilization in arid regions. The RCD growth rate of P. sibirica was significantly decreased by the treatment of high-level of nitrogen due to excessive nitrogen fertilization, and was increased by the treatment of ammonium sulfate due to sulfur which might promote nitrogen uptake. The leaf nitrogen concentration of P. sibirica did not change by the treatment of low-level of nitrogen, and was increased by the treatment of medium-level of nitrogen. There were no significant differences in the RCD growth rate and the leaf nitrogen concentration of U. pumila among the six treatments. None of soil chemical properties was affected by nitrogen fertilization. Overall, the low-level of nitrogen showed no effect on seedlings and soil chemical properties, except on survival rate of U. pumila and the high-level of nitrogen was considered excessive fertilization. Continuous monitoring of medium-level nitrogen fertilization including the ammonium sulfate, which increased early growth of seedlings, would be needed to elucidate the effect of fertilization on seedling growth and soil properties in a semi-arid region.

• Applied Biological Chemistry
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• v.26 no.4
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• pp.248-254
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• 1983

The effects of some soil conditions on the degradation rate and decomposing pattern of thiolix were investigated and the obtained results are summarized as follows: Thiolix degraded more rapidly in flood soils than in noon-flooded, and in wet soils than in dry soils under non-flooded soils. The degradation rates in non-flooded soils increased with higher pesticide concentration. Thiolix was more persistent in non-flooded soils under soil sterelization than under non-sterilization and degraded rapidly in glucose application. The metabolites identified from the soils by TLC and GLC include Thiolix alcohol, Thiolix sulfate, Thiolix ether and a unknown metabolite. Soil enzyme, acid phosphatase activity decreased at higher pesticide concentration, lower moisture contents of soil and the activity in glucose application was increased. Soil enzyme, urease and dehydrogenase activity decreased at higher pesticide concentrations.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2002.04a
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• pp.330-333
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• 2002

Immobilization isotherms for methyl tort-buty1 ether (MTBE) in sodium dodecy1 sulfate(SDS) and cetylpyridinium chloride (CPC) were investigated for application to micellar enhanced remediation. Headspace solid-phase microextraction was used to analyze immobilization isotherms. Maximum partitioning coefficients of MTBE were 48 L/mol and 9 L/mol for SDS and CPC, respectively, The values decreased gradually as the MTBE mole fraction in the micelles increased.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2005.10a
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• pp.201-201
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• 2005

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2005.10a
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• pp.250-251
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• 2005

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2001.09a
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• pp.151-154
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• 2001

To assess the remediation possibility of groundwater contaminated with MTBE, micellar solubilization by various surfactants was evaluated. Micellar solubilization is basic phenomena to apply micellar enhanced ultrafiltration for groundwater remediation contaminated with MTBE. Sodium dodecyl sulfate (SDS) shows the best removal efficiency among various nonionic, cationic and anionic surfactants. Molar ratio of SDS to MTBE was the most important factor for removal of MTBE using micellar solubilization. With the ratio of more than 13, the removal efficiency was saturated to 55%.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.09a
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• pp.382-385
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• 2003

QAMDI(Quantified Acid Mine Drainage Index) was developed for more synthesised, qualified and quantified assessment index which can be applied to both coal and metal mine drainage. QAMDI is calculated using three parameter groups i.e. acidity, sulfate contents and toxic metal contents. Since QAMDI expressed in terms of concentration. It reveals the different status of each mine drainage more clearly. QAMDI can be converted to the quantity of pollutant loading by being multiplied by the water flux.

• Mycobiology
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• v.28 no.4
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• pp.180-184
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• 2000

In order to find an environment-friendly method to suppress astragal stem rot caused by the isolates of Rhizoctonia solani AG 1 and AG 4, we tested an antagonistic fungus Gliocladium virens G1 was evaluated as a biocontrol agent and estimated inorganic compounds and organic materials were tested for their effect of the disease suppression. G. virens G1 effectively inhibited mycelial growth in a dual culture and caused mycelial lysis in the culture filtrate. No adverse effect was observed when examined for seed germination and seedling growth. Promoted seedling growth was observed with the seed treatment. Seeds of astragal plant were germinated higher in the sterile soil than the natural soil. Of 14 inorganics tested, alum, aluminum sulfate and calcium oxide significantly suppressed the mycelial growth and sclerotial germination. Milled pine bark and oak sawdust also suppressed the mycelial growth. Soil amended with 1% of G. virens G1 composted with pine bark (w/v) significantly controlled astragal stem rot in the glasshouse experiments.

• Korean Journal of Soil Science and Fertilizer
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• v.30 no.4
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• pp.328-333
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• 1997

A study was conducted to examine the effect of application of Diazinon at different rates in submerged soil under the application of different N fertilizers; urea, ammonium sulfate and organic fertilizer(fermented chicken dung-sawdust mixture). The levels of Diazinon application were equivalent to zero, 350 mg a. i./ha, 700 mg a. i./ha and 1050 mg a. i./ha. To 100 gr of air-dry soil, 10 mg of N, $P_2O_5$ and $K_2O$ and different levels of Diazinon were mixed thoroughly and the soil was submerged in 100 ml of distilled water. The submerged soil was incubated at $30^{\circ}C$ for 50 days. Volatilied ammonia was measured at every 10 days. The amount of ammonia volatilization was greatest in urea treated soil, followed by organic fertilizer and it was the least in ammonium sulfate treated soil. The application of Diazinon at 700 mg a. i./ha increased the volatilization of ammonia greatly in the urea treated soil. Under other fertilizers, the effect of Diazinon application was not remarkable. The increase in the soil pH during the incubation period under different fertilizer treatments tended to increase ammonia volatilization.

• Journal of Soil and Groundwater Environment
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• v.15 no.1
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• pp.29-38
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• 2010

Batch tests were carried out to examine the influence of the presence of soil and Fe(II) sorption capacity of soil on the ferrous catalyzed sodium persulfate oxidation for the destruction of organic pollutants in the application of in-situ chemical oxidation. Laboratory column tests were also conducted to investigate the transport of oxidant and catalyst in contaminated groundwater. Test results proved that Fe(II) was adsorbed on soil surface, and thus soil behaved as a heterogeneous catalyst, enhancing the naphthalene removal rate up to 50%. Column tests that were conducted with and without dissolved Fe(II) showed that naphthalene removal ratio were 24% and 25%, respectively. The removal efficiency was not enhanced with dissolved Fe(II), since the dissolved Fe(II) flew out of the column as the oxidant progressively injected into the column saturated with Fe(II). It indicates that the injected oxidant could not interact with dissolved Fe(II). But target organic pollutant was degraded in soil column system, implying that sulfate radical was produced by the reaction of dissolved persulfate with Fe(II) adsorbed on soil.