• Journal of Korean Society of Forest Science
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• v.98 no.4
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• pp.357-362
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• 2009

Trials to find a method for overcoming the depletion of Tricholoma matsutake mycorrhiza from the artificially inoculated pine seedling (Pinus densiflora) when it is transplanted in situ were carried out. The culturing jars containing mycorrhizal seedlings were punched at the bottom to make the jar like a pot with keeping the soil structure of the original medium in vitro, and 8 kinds of irrigation solution were applied. Irrigation of distilled water caused disappearance of T. matsutake mycorrhizae, but biweekly irrigation of 2.5% PDMP (24 g potato dextrose broth, 3 g malt extract, 1 g peptone) solution or 0.5% Tween 80 solution until 3 months of acclimation could keep mycorrhizal association stronger. The percentage of mycorrhizal roots out of total length of roots was increased during the acclimation, and the acclimation rate reached up to 70%. Thus, we recommend that the mycorrhizal pine seedlings inoculated with T. matsutake would be acclimated before transplanting into the field.

• Horticultural Science & Technology
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• v.16 no.2
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• pp.226-228
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• 1998

The objective of this study was to observe the effects of potassium-cyanoethylstarch (K-CES), which is a natural polymer derivate,. and polyacrylamide (PAM), which is a synthetic polymer, on the growth of spinach under environment-controlled biotron. K-CES was made from tapioca starch, and introductions of acrylonitrile was confirmed by FT-IR. Water absorbing capacities (WAC) of K-CES and PAM were 37.6 and 47.8 times, respectively. WAC of PAM was slightly higher than K-CES, WAC of PAM m saline solutions were more reduced than those of K-CES. It was introduced that K-CES treatment was more effective than PAM in higher salinity of water and soil. Dry super absorptive polymers were put into solution, and the solution was applied to soil as an soil conditioner. Both amendments, K-CES and PAM, increased the vegetative growth of the spinach when applied at 0.1% of soil weight. In general, the most favorable results for early vegetative growth of the spinach came from the PAM treatment, followed by the K-CES treatment.

• Journal of Soil and Groundwater Environment
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• v.11 no.2
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• pp.1-12
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• 2006

A model describing the distributions of surfactants and HOCs (hydrophobic organic chemicals) in surfactant/HOC/activated carbon systems for surfactant reuse in soil washing process was developed. The model simulation was conducted for the evaluation of the effect of concentrations of surfactant, HOC, or activated carbons. Phenanthrene as a target HOC, Triton X-100 as surfactant and three granular activated carbons with different particle sizes (4-12, 12-20, and 20-40 mesh) were used in the model simulation. The distributions of HOC were significantly affected by surfactant dosages, especially at around the CMC(s). The results of selectivities for phenanthrene were much larger than 1 at various concentrations of surfactants, phenanthrene and activated carbons, which mean that the selective adsorption of phenanthrene by activated carbons is a proper separation method from surfactant solution. The model can be applied for the design of the surfactant reuse process using activated carbons without extra experimental efforts.

• Clean Technology
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• v.23 no.3
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• pp.302-307
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• 2017

This study was conducted to evaluate the feasibility of in situ soil flushing for TPH-contaminated soil remediation with column test. The soil texture of the soil was sand and the initial TPH concentration was $9,369mg\; kg^{-1}$. 0.1% Tween-80 was selected as surfactant solution. And the acrylic and the glass syringe columns were used as reactors. In the acrylic column test, 35% of the initial TPH was removed in 1 PV of flushing and approximately 40% in 5 PV and finally 7 PV showed about 60%. The glass column test showed 3 ~ 12% higher removal efficiency than that of acrylic test until 5 PV of flushing. However, there was no difference in TPH removal efficiency when 7 PV of surfactant was finally flushed. Both of alum only and alum+polymer mixed surfactants showed also the best coagulation efficiency in $150mg\;L^{-1}$ of concentraion. When Tween 80 was newly dissolved in 0.1% to the recovered solution after the coagulation treatment, the removal efficiency was increased from 32.0% to 41.0% in comparison to the new 0.1% Tween 80 solution without reuse by coagulation treatment.

• Korean Journal of Soil Science and Fertilizer
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• v.25 no.2
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• pp.133-137
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• 1992

The rate and pattern of soil nitrogen mineralization were investigated under conditions of a paddy-upland switching cultivation system. Experimental results obtained are as follows 1. Amounts of soil nitrogen mineralized were different in the order of potato-cabbage>soybean>continuous paddy plot for the first year, but potato-cabbage>continuous paddy>soybean plot for the second year, respectively. 2. In the third year cropping under upland condition a higher amount of soil nitrogen was found mineralized at the plot of continuous upland cultivation than at the alternate paddy-upland switching plot in the case of potato-cabbage, on the contrary, however, the higher amount was found at the alternate paddy-upland switching plot in the case of soybean cultivation. 3. The amounts of total soil nitrogen and carbon were lower in paddy-upland switching plots than in continuous paddy plots. This trend is significant in soybean plots. 4. A positive correlationship was found between phosphate buffer solution method for available nitrogen and submerged soil method for $NH_4-N$, both being utilized for the estimation of soil fertility.

• Journal of Radiation Protection and Research
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• v.36 no.4
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• pp.209-215
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• 2011

In order to investigate the soil-to-plant transfer factor (TF) of $^{99}Tc$ for Korean major upland crops (soybean, radish and Chinese cabbage), pot experiments were performed in a greenhouse. Soils were collected from four upland fields (two for soybean and two for radish and Chinese cabbage) around Gyeongju radioactive-waste disposal site. Three to four weeks before sowing, dried soils were mixed with a $^{99}Tc$ solution and the mixtures were put into pots and irrigated. TF values were expressed as the ratios of the $^{99}Tc$ concentrations in plants (Bq $kg^{-1}$-dry or fresh) to those in soils (Bq $kg^{-1}$-dry). There was no great difference in the TF value between soils. The TF values for soybean seeds were extremely lower than those for the straws, indicating a very low mobility of $^{99}Tc$ to seeds. As representative TF values of $^{99}Tc$, $1.8{\times}10^{-1}$, $1.2{\times}10^1$, $3.2{\times}10^2$ and $1.3{\times}10^2$ (for dry plants), arithmetic means for two soils, were proposed for soybean seeds, radish roots, radish leaves and Chinese cabbage leaves, respectively. In the case of the vegetables, proposals for fresh plants were also made. The proposed values are not sufficiently representative so successive updates are needed.

• Horticultural Science & Technology
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• v.16 no.2
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• pp.222-225
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• 1998

The objective of this study was to observe the effects of potassium-carboxymethyl cellulose (K-CMC), which is a natural polymer derivative, and polyacrylamide (PAM), which is a commercial synthetic polymer, on soil physicochemical properties and yields of the cabbage. To increase water absorbing capacity (WAC), hydrophilic carboxymethyl group was introduced to cellulose chain and it was confirmed by FT-IR. WAC was tested by tea-bag method in distilled water and 3% NaCl solution. PAM is slightly more absorptive than K-CMC in distilled water, but in NaCl solution, K-CMC is more absorptive than PAM. Soil particle sizes above $1_{mm}$ were immediately increased from 9.6 to approximately 16.6% by the application of K-CMC and PAM, respectively. Infiltration rates of soil were approximately twice as great as those of the control when conditioned with the K-CMC and PAM treatment. K content of soil treated with K-CMC was significantly higher than those of PAM and control, but the other components of soil chemical properties were not different. The early growth and vegetative production of cabbage in the K-CMC and PAM treatments were significantly higher than the control. The contents of vitamin C were increased with the treatment of K-CMC. It was proposed that K-CMC treatment influence K component of the soil and vitamin C content of the cabbage, therefore, it improved the yields as well as crop quality.

• Journal of Soil and Groundwater Environment
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• v.10 no.1
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• pp.1-5
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• 2005

Nitrate reduction with zero valent iron $(Fe^0)$ has been extensively studied, but the proper treatment for ammonium byproduct has not been reported yet. In groundwater, however, ammonium is regarded as contaminant species, and particularly, its acceptable level is regulated to 0.5 mg-N/L. for drinking water. This study is focused on developing new material to reduce nitrate and properly remove ammonium by-products. A new material, Fe-loaded zeolite, is derived from zeolite modified by Fe(II) chloride followed by reduction with sodium borohydride. Batch experiments were performed without buffer at two different pH to evaluate the removal efficiency of Fe-loaded zeolite. After 80 hr reaction time, Fe loaded zeolite showed about $60\%$ nitrate removal at initial pH of 3.3 and $40\%$ at pH of 6 with no ammonium release. Although iron filing showed higher removal efficiency than Fe-loaded zeolite at each pH, it released a considerable amount of ammonium stoichiometrically equivalent to that of reduced nitrate. In terms of nitrogen species including $NO_3-N$ and $NH_4^+-N$, Fe-loaded zeolite removed about $60\%\;and\;40\%$ of nitrogen in residual solution at initial pH of 3.3 and 6, respectively, while the removal efficiency of iron filing was negligible.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.4
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• pp.490-497
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• 2010

A chitinolytic bacterium having a strong antagonistic activity against various pathogens including Phytophtora capsici was isolated from rhizosphere soil, and identified as Lysobacter enzymogenes (named as LE429) based on 16S rRNA gene sequence analysis. This strain produced a number of substances such as chitinase, ${\beta}-1$, 3-glucanase, lipase, protease, gelatinase and an antibiotic compound. This antibiotic compound was purified by diaion HP-20, sephadex LH-20 column chromatography and HPLC. The purified compound was identified as phenylacetic acid by gas chromatography-electron ionization (GC-EI) and gas chromatography-chemical ionization (GC-CI) mass spectrometry. In field experiment, pepper plants were treated by the strain LE429 culture (CB), neem oil solution (NO), combination (CB+NO) or control (CON). Plant height and number of branches, flowers and pods of pepper plant in CB treatment were generally highest, and followed by CB+NO, CON and NO. The fungal pathogens were strongly inhibited, while several insect pests were discovered in CB treatment. Any insect pests were not found, while all fungal pathogens tested were not suppressed in NO treatment. However, in CB+NO treatment, non incidence of fungal pathogens and insect pests were found. The strain LE429 producing secondary metabolites with neem oil should be a potential agent to control fungal diseases and insect pests.

• Journal of Soil and Groundwater Environment
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• v.9 no.1
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• pp.87-94
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• 2004

The effects of pretreatment of GAC and dissolved oxygen (DO) on the sorption capacity for ο-cresol were investigated using pretreated GAC under oxic and anoxic conditions. Virgin GAC was used with pretreated GACs by $O_2$, acid and base as sorbents. Sorption capacity of GAC was dependent on the oxygen conditions according to the pretreatment methods. Virgin GAC showed increased sorption capacity when DO was present in the solution, while $O_2$-pretreated GAC did not show any considerable capacity change. Acid- and base-pretreated GACs were relatively more influenced by presence of DO as compared with virgin GAC. Both acid and base-pretreated GACs showed a rapid sorption rate at the initial stage, but as contact time became longer the sorption was slower. Sorbed ο-cresol was extracted with micro-Soxhlet extraction apparatus using the GAC separated from the rate experiments. Within 1 hour both acid and base-pretreated GACs showed the decrease in extraction efficiencies under both oxic and anoxic conditions. After 1 hour such a trend (the increase as contact time was longer) was not observed and showed relatively constant efficiencies of 35∼50%. According to the results of this study $O_2$contacted with GAC before sorption as well as DO present in the solution during sorption could influence the GAC sorption capacity.