• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2004.09a
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• pp.211-214
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• 2004

MTBE로 오염된 토양에서 생태독성학적 접근 방법으로 3가지 토양 효소의 활성도를 측정해 보았다. MTBE의 잠재적 위험성으로 인한 논란은 계속되고 있으나 토양 오염에 대한 지표로써 토양 효소 활성도의 사용타당성 여부에 대한 실험은 이전에 행해지지 않았다. 따라서 중금속 오염 토양에 대해 좋은 지표로 사용되고 있는 토양 미생물 효소의 활성도를 MTBE에 적용하여 실험해 보았다. 사용한 토양 효소는 Acid Phosphotase, $\beta$-Glucosidase 그리고 Arysulfatase였다. 그러나 실험 결과 MTBE로 오염된 토양의 경우 중금속으로 오염된 토양에 비해 토양 미생물 활성도의 감소가 매우 적었다. 따라서 MTBE의 오염 토양의 경우 본 연구에서 측정된 효소의 활성도는 좋은 지표로 적합하지 않다는 것을 확인했다.

• Korean Journal of Soil Science and Fertilizer
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• v.18 no.1
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• pp.105-110
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• 1985

A incubation study was conducted to find out the effects of rice straw and gypsum as soil ameriolite on urease, nitrate and nitrite reductase activities in newly reclaimed saline sandy soil. The results obtained were summarized as follows: 1. Very low urease activities were observed in saline soil if contrast to high productive paddy soil. Urease activities were lower at 5 days than that of 25 and 50 days after incubation. Remarkably high urease activities were obtained by the application of rice straw and gypsum. 2. Comparing with NPK treatment, application of rice straw and gypsum were enhanced the activities of nitrate and nitraite reductase. 3. Positive correlation (r=0.5501 p=0.05) was obtained between urease activities and ammonium nitrogen concentration in soil. 4. Cyclic oxidation and reduction of nitrate and nitrite in soil were obtained in terms of first order microbial kinetics reaction in case of application of rice straw and gypsum, respectively. 5. Positive correlation (r=0.6296 p=0.05) was obtained between the activitie of nitrite reductase and nitrate reductase in soil.

• Korean Journal of Soil Science and Fertilizer
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• v.46 no.2
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• pp.122-128
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• 2013

This study was carried out to evaluate the soil dehydrogenase activity and microbial biomass C with soil type and land use in cropland of JeJu region. Soil chemical properties, dehydrogenase activity, and microbial biomass C were analyzed after sampling from upland (50 sites), orchard (50 sites), paddy (30 sites), horticultural facility (30 sites) in March. Average pH values was at 6.3 in upland soil, however soil chemical properties showed a large spatial variations in both orchard and horticultural facility soil. The Zn and Cu contents increased by the continuous application of pig manure compost in some citrus orchard soil. Soil dehydrogenase activity and microbial biomass C were higher in non-volcanic ash than in volcanic ash soil regardless of land use type. Soil dehydrogenase activity was two to four times higher in upland than in the others. It was at 38.7 ug TPF $24^{h-1}g^{-1}$ in non-volcanic ash of upland soil. Microbial biomass C content was very high in horticultural facility soil and it showed at 216.8 $mg\;kg^{-1}$ in non-volcanic ash. Soil dehydrogenase activity showed a positive correlation with organic matter ($r^2$=0.59), Zn ($r^2$=0.65), and Cu ($r^2$=0.66) in non-volcanic ash horticultural facility soil. There was a negative correlation ($r^2$=0.57) between soil organic matter and dehydrogenase activity in volcanic ash upland soil.

• Korean Journal of Soil Science and Fertilizer
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• v.40 no.4
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• pp.229-233
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• 2007

A long-term rice paddy field, which is located in the National Institute of Crop Science (Suwon city, Korea) has been managed for studying of fertilization and composting impact on paddy soil fertility since 1954. The objective of this research was to evaluate soil quality through dehydrogenase analysis in long-term paddy soil treatment plots, such as control, N fertilization (N), NPK fertilization (NPK), and rice straw compost with NPK (CNPK). Dehydrogenase-producing bacterial population developing red-colored triphenyl formazan (TPF) was highly correlated to the dehydrogenase activity in rice paddy soils sampled prior to waterlog. The dehydrogenase-producing bacterial population and dehydrogenase activity was comparatively high in plots of NPK, and CNPK, which organic matter content was relatively high.

• Journal of Wetlands Research
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• v.14 no.1
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• pp.47-57
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• 2012

We have measured soil enzyme activities, which represent the rates of organic matter decomposition, in four riparian ecosystems in Korea. ${\beta}$-glucosidase, N-acetylglucosaminidase, phosphatase and arylsulfatase activities were determined in five occasions over a year period in soils of control plots and plots with invasive plants, namely Sicyos angulatus and Humulus japonicus. Significantly higher enzyme activities were found in soils with invasive plant in barren land, but the difference was season and enzyme-specific. Although it was not universal changes, the invasive plants appeared to accelerate organic matter decomposition in some disturbed riparian ecosystems.

• Korean Journal of Environment and Ecology
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• v.26 no.6
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• pp.902-910
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• 2012

This study has been carried out to determine the effects of disturbances from wild boar grubbing on the functions of ecosystem. The experiments was performed in Mt. Jumbong of Long-term Ecological Research Sites of the Ministry of Environment. We measured soil physical properties, soil respiration($CO_2$), microbial biomass C, and soil enzyme activities from both disturbed and control plots. The disturbance sites were divided into two parts, mounds and pits. Soil organic matter contents were highest value at the control plots and lowest at the pit plots, respectively at 20.22% and 15.52%. The soil bulk densities were highest at the pit plots. Soil microbial biomass C and $CO_2$ evolution were significantly higher at the control plots compared to the disturbed plots. The results were positively correlated with soil organic matter contents. The cellulase activity and invertase activity in the soil showed similar pattern as the microbial biomass C and $CO_2$ evolution results. The cellulase activity and invertase activity in the soil were positively correlated with soil microbial biomass C. Soil organic matter contents seemed to affect the soil enzyme activities. The nitrate reductase activities were highest at the pit plots, which showed positive correlation with soil bulk density. The study results showed that the grubbing disturbances by wild boars induced the changes in soil properties, which affected soil microbial activities.

• Korean Journal of Environment and Ecology
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• v.16 no.1
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• pp.46-54
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• 2002

This study was conducted to diagnose the health of street trees with physiological characters, and to figure out the relation of physiological characters and cambial electrical resistances. Ginkgo biloba, Prunes serrulata and Salix koreensis were chosen in the Cheonan City. Soils under trees were collected to analyze dehydrogenase activities, and chlorophyll content, nitrate reductase and superoxide dismutase activities were analyzed from leaves sampled at the edge of crown in July. Cambial electrical resistances were measured in May, July and September, Soils with low dehydrogenase activity reflected the level of pollution. Chlorophyll content was the lowest in the leaves of P. serrulata at the Dongseo-street. Nitrate reductase activity of Ginkgo biloba was higher than P. serruluta and Satix koreensis. Nitrate reductase activity showed higher activity in the city than control(Independence Hall and Yonam College), but superoxide dismutase activity in the city lower than control. P. serruzatu in the Dongseo-street that cambial electrical resistance increase continuously during the growing season, showed the loss of vitality Cambial electrical resistance was negatively or positively correlated with nitrate reductase($r^2$=-0.566) and superoxide dismutase activity($r^2$=0.579). It was concluded that cambial electrical resistance might be suitable for diagnosing the tree health.

• Korean Journal of Soil Science and Fertilizer
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• v.38 no.5
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• pp.281-286
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• 2005

The effect of oyster shell meal, which is made of a simple crushing and alkaline calcium materials, on soil microbial properties, microbial biomass C, N and P contents, and enzyme activities were evaluated in silt loam soil. The oyster shell meal fertilizer was added at the rates of 0, 4, 8, 12 and $16Mg\;ha^{-1}$. Microbial biomass C, N and P contents were significantly increased with increasing application of oyster shell meal. Soil enzyme activities, such as urease, ${\beta}$-glucosidase and alkaline phosphomonesterase were increased significantly by shell meal application, due to increased soil pH towards neutral range and increased nutrient availability in soil. In particular, the increased microbial biomass P content and phosphomonoesterase activities were strongly correlated with available P content in soil. Conclusively, oyster shell meal fertilizer could be a good supplement to improve soil microbial activities.

• Korean Journal of Soil Science and Fertilizer
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• v.42 no.4
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• pp.307-316
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• 2009

Soil microbial activity and diversity are affected by organic sources applied to improve soil quality and fluctuate seasonally. We investigated the effects of municipal compost (MC), poultry litter (PL), and cover crops of spring oats and red clover (RC) on soil enzyme activities, and soil bacterial community-level physiological profiling (CLPP) in a Mexico silt loam in North Central Missouri, USA. Temporal patterns of these parameters were observed by periodic five soil sampling from spring to fall over a two year period. MC increased soil dehydrogenase (DH) activity consistently beginning about three months after MC application; fluorescein diacetate (FDA) hydrolytic activity significantly began to increase by the September of the first year but fluctuated during the following period. DH activity responded more directly to the amount or properties of organic residues in soils while FDA hydrolysis and CLPP were generally influenced by composition of organic sources, and enzyme activities and CLPP showed seasonal variation, which depended on organic sources and soil moisture. MC and cover crops may be useful organic sources for enhancing general soil microbial activity and altering soil microbial diversity, respectively. Because microbial activities and diversity are dynamic and subject to seasonal changes, the effects of organic amendments on these parameters should be investigated frequently during a growing season.

• Journal of Ginseng Research
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• v.25 no.1
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• pp.53-58
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• 2001

To clarify a significant difference between red-colored phenomena (RCP) and microbes isolated from rhizosphere soil of healthy ginseng (HES) and red-colored ginseng (RCS), we have examined growth and cellulase activities of the microbes according to pH variation and iron status. The soil microbes could not grow at pH 3.0 on the YEB medium. The growth of bacterium isolated from RCG at pH from 5.0 to 9.0 showed small differences and the growth of bacterium HES was lower than that of others. The growth of bacteria from RCS and surface soil (SUS) at pH 5.0 were also lower than that of pH 7.0 and pH 9.0. However, the bacteria isolated from red-colored ginseng (RCG) and RCS are able to grow on the medium contained 2 mM Fe$\^$3+/ at pH 3.0. Furthermore, the growth of bacterium from RCG increased about two times in the medium contained iron at pH 7.0 compared with minus iron. The cellulase activity of isolated bacteria increased two times in the medium contained 2 mM Fe$\^$3+/ compared with minus iron. The activity of extra-cellular cellulase was higher by one hundred times than that of intracellular level. The cellulase activity of the bacterium from RCS at pH 5.0 was higher by two times than that of pH 7.0. Especially, intracellular activity of the bacterium from RCS on the medium contained 2mM Fe$\^$3+/ increased about six to seven times compared with control (minus iron). Also, extra-cellular activity increased about eleven to twelve times compared with control. These results indicate that the soil microbes seem to be related iron redoxidation by proton extrusion and with cell wall digestion by secreted cellulase.