• Korean Journal of Soil Science and Fertilizer
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• v.47 no.2
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• pp.113-119
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• 2014

Arsenic and its compounds which is one of the most toxic elements that can be found naturally on earth in small concentrations are used in the production of pesticides, herbicides, and insecticides. Most arsenic that cannot be mobilized easily when it is immobile is also found in conjunction with sulfur in minerals such as arsenopyrite (AsFeS), realgar, orpiment and enargite. In this investigation we observed the leaching of arsenic in soils amended with several levels of gravel size of arsenopyrite collected from a road construction site. Soil and gravel size of arsenopyrite were characterized by chemical and mineralogical analyses. Results of XRF analysis of arsenopyrite indicated that the proportion of arsenate was 0.075% (wt $wt^{-1}$) while the maximum amount of arsenic in soil samples was 251.3 mg $kg^{-1}$. Cumulative amounts of effluent collected from the bottom of the soil column for different mixing rate of the gravel were gradually increased where proportion of the gravel mixed was greater than 70% whereas the effluent was stabilized to the maximum after approximately 45 pore volumes of effluent or greater were collected. The arsenic in the effluent was recovered from the soil columns in which the proportion of arsenopyrite gravel was 60% or greater. The total amount of arsenic recovered as effluent was increased with increasing proportion of gravel in a soil, indicating that the arsenic in the effluent was closely related with gravel fraction of arsenopyrite.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.13 no.6
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• pp.97-106
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• 2010

Earthworm, a prominent ecosystem engineer within many terrestrial ecosystems, can exert profound influences on various abiotic/biotic environments through bioturbation processes such as burrowing, casting and mixing of litter and soil. In this study, we investigated how the presence or absence of earthworm (Oligochaeta) can alter the soil physico-chemical conditions and ultimately the distribution and abundance of Collembola which constitutes a large proportion of the soil fauna. During September 2010, soil organisms along with soil samples were collected from randomly installed 20 plots in Mt. Gwan-ak. We examined the differences in the abundance of Collembola among plot samples in respect to the presence/absence of earthworm and soil physico-chemical conditions (i.e., pH, $PO_4^{3-}$, $NO_3^{2-}$, organic matter (OM), electrical conductance and water content). Analysis of soil physico-chemical environment revealed a significantly higher organic matter content and electrical conductance in plots with earthworm compared to plots without earthworm. Abundance of Collembola were not only higher in plots with earthworm than in plots without earthworm, but were also positively correlated with availability of OM present in the environment. The results suggest that positive impacts of earthworm on the abundance of Collembola in this study may have been due to their ability to effectively modify soil physico-chemical conditions favored by Collembola. Such conspicuous influence of earthworm's activity on below-ground community suggests their potential significance in forest restoration or revegetation process.

• Korean Journal of Soil Science and Fertilizer
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• v.49 no.2
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• pp.132-137
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• 2016

Field monitoring was performed to evaluate the chemical properties of 260 paddy soils every 4 years from 1999 to 2015 in Gyeongnam province. Soil chemical properties, including soil pH, electrical conductivity, amount of organic matter (OM), available phosphate ($P_2O_5$), exchangeable potassium (K), calcium (Ca), magnesium (Mg) and sodium (Na), and available silicate ($SiO_2$) were analyzed. In 2015, the average values of pH, OM, available $P_2O_5$, exchangeable K, Ca, and Mg, and available $SiO_2$ was 5.8, $30g\;kg^{-1}$, $222mg\;kg^{-1}$, $0.37cmol_c\;kg^{-1}$, $6.5cmol_c\;kg^{-1}$, and $1.4cmol_c\;kg^{-1}$, $252mg\;kg^{-1}$, respectively. The frequency distribution within optimum range of paddy soils was 49.2%, 20.8%, 18.5%, and 5.8% for soil pH, OM, available $P_2O_5$, and available $SiO_2$, respectively. The available $P_2O_5$ concentrations in 2015 was excess level with portion of 58% and did not alter significantly during the experimental period. Although the average of available $SiO_2$ concentration has tended to increase with every year, the insufficient proportion of available $SiO_2$ concentration in 2015 was 48%. These results indicated that a balanced management of soil chemical properties can properly control the amount of fertilizer applied for sustainable agriculture in paddy field.

• Korean Journal of Medicinal Crop Science
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• v.28 no.2
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• pp.142-151
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• 2020

Background: Suppressive soil inhibits soil-borne diseases if pathogens are present, and ginseng does not show injury even if replanted in the same field. Methods and Results: Soil chemical properties and microbial community of soil were investigated in soil suppressive and conducive to ginseng root rot. Root rot disease in 2-year-old ginseng was tested by mixing conducive soil, with suppressive or sterilized suppressive soil. The root rot ratio in suppressive soil was 43.3% compared to 96.7% in conducive soil. Biological factors acted to inhibit the root rot because disease ratio was increased in the sterilized suppressive soil compared to that in non-suppressive soil. The suppressive soil had lower pH, nitrate nitrogen and sodium than the conducive soil. Dominat bacteria and fungi (more than 1.0%) were 3 and 17 species in conducive soil and 7 and 23 species in suppressive soil, respectively. The most predominant fungi were Pseudaleuria sp. HG936843 (28.70%) in conducive soil and Pseudogymnoascus roseus (7.52%) in suppressive soil. Conclusion: Microbial diversity was more abundant in the suppressive soil than in the conducive soil, and the proportion of pathogens (Nectriaceae sp.) causing root rot was significantly lower in the suppressive soil than in the conducive soil.

• Korean Journal of Soil Science and Fertilizer
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• v.50 no.1
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• pp.31-39
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• 2017

The effects of application of gypsum and fresh cattle manure on the yield of forage crop were investigated in Hwaong reclaimed land in Korea for 3 years from 2011 to 2013. This study was conducted to develop the practical application method of livestock manure as a fertilization source and a soil physico-chemical ameliorator for the cultivation of forage crop $Sorghum{\times}Sudangrass$ hybrid in newly reclaimed tidal land soil. Treatments with six applications were established with three replications; chemical fertilizer (CF), gypsum (G) $20Mg\;ha^{-1}$, G+fresh cattle manure (FCM) 100%, G+FCM 200%, G+FCM 300% and FCM 100% which referred to the application rate equivalent to the recommended amount of phosphate fertilization by soil test. The combined treatments of G+FCM increased soil organic matter, $Av.P_2O_5$ and exchangeable $Ca^{2+}$ contents while decreased exchangeable $Na^+$ and $Mg^{2+}$. The soil bulk density, soil hardness and soil aggregate formation were improved by G+FCM treatments. The dry matter yields of $Sorghum{\times}Sudangrass$ hybrid were significantly increased in proportion to the application rate of FCM. The phosphorus use efficiency showed the highest in the application level of G+FCM 100%, which seemed to be the results of reduced nutrient use efficiency by nutrient immobilization, leaching etc. when applied excessive amount of fresh animal manure.

• KCID journal
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• v.21 no.1
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• pp.99-108
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• 2014

This study investigated the effects of NPS(non point source) pollution reduction of sediment traps through field experiments. Various sizes of 4 sediment traps were applied in a upland field located in Gunwi and assessed the infiltration and storage effects as well as NPS pollution reduction effects of this technique. The characteristics of deposited soil in the sediment traps were also analyzed including distribution of particle size, soil texture, and chemical properties. The results showed that slightly different composition of soil particle size from each sediment trap with high proportion of 0.15mm and 0.25mm ranges of soil particle diameters, while the loamy sand is the main types of deposited soils in the sediment traps. Decreased NPS pollution were observed from the water quality analysis of the samples taken from the sediment traps. Further research need to be proceeded continuously to improve this technique in order to utilize on upland fields for management of agricultural NPS pollutions.

• Korean Journal of Soil Science and Fertilizer
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• v.46 no.6
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• pp.641-646
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• 2013

Chemical properties of agricultural soils in Korea have been investigated at four-year interval in order of paddy, polytunnel, upland, and orchard soils since 1999; polytunnel soils were investigated over the whole country in 2000, 2004, 2008, and 2012. Polytunnel soils were taken from the surface (0-15 cm) and subsurface (15-30 cm) at 2,651, 1,274, 1,374 and 1,374 sites in all provinces of South Korea. One hundred sampling sites located in more than 400 m altitude were additionally investigated in 2008 and 2012. Average of soil chemical properties in 2012 except Jeju province were 6.6 for pH, 3.2 dS $m^{-1}$ for EC, 37 g $kg^{-1}$ for organic matter (OM), 1,049 mg $kg^{-1}$ for available (Avail.) phosphate, 1.58 $cmol_c\;kg^{-1}$ for exchangeable (Exch.) K, 10.6 $cmol_c\;kg^{-1}$ for Exch. Ca, and 3.3 $cmol_c\;kg^{-1}$ for Exch. Mg. Except pH, averages of all chemical properties exceeded the upper limit of optimal range. The median values except pH showed a lower value than the averages. The pH, OM and Exch. Ca had slightly increased from 6.3 to 6.6, from 34 to 37 g $kg^{-1}$, and from 7.7 in 2000 to 10.6 $cmol_c\;kg^{-1}$ in 2012, respectively. The order of sample ratios exceeding the optimal range were Avail. $P_2O_5$ (83%) > Exch. Ca (80%) > Exch. K (70%) > Exch. Mg (65%) > EC (55%) > OM (48%) > pH (29%) in 2012. The order of sample ratios below the optimal range was OM (25%) > Exch. K (25%) > pH (20%), Exch. Mg and Avail. $P_2O_5$ (9%) > Exch. Ca (6%) in 2012. The excessive proportion of pH, Exch. Ca, Exch. Mg and OM slightly increased, while the insufficient proportion of those decreased. Approximately 55% of polytunnel soils exceeding EC 2 dS $m^{-1}$ was evaluated with salt accumulated soils having the risk of growth disorder of crops. Nutrient contents in polytunnel soils in Korea showed high level especially Avail. $P_2O_5$ and Exch. cations. Therefore, recommended fertilization based on soil testing or plant testing is needed for soil nutrient management.

• Journal of the Korean GEO-environmental Society
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• v.10 no.4
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• pp.25-31
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• 2009

In this study, the problem of existing soil pavement is a long-term durability lack and crack occurrence. It complements in order to develop the environmental soil pavement material which composites readily blended mineral binder of liquid and decomposed granite soils. It was estimated optimal mixture proportion for unconfined compressive strength, permeability, $Cr^{6+}$detection test, SEM test with age, freezing and thawing test. It resulted mixture proportion of powder types mineral binder for rates of cement : fly ash : plaster was optimal rates of 50 : 33 : 7, and $Cr^{6+}$detection test as a result was a slight production. SEM test with 3days as a result was made Ettringite. It was found that this material was early development of early-strength for chemical. This study indicated that it will execute field appliciability Evaluation test, examination of soil pavement method with decomposed granite soils and mineral binder.

• Korean Journal of Soil Science and Fertilizer
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• v.31 no.4
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• pp.420-426
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• 1998

This investigation was undertaken to clarify the effects of application of chemical fertilizers (Compound fertilizer and commercial compost) and organic matters (straw and clover) on changes of the composition of soil actinomycetes flora. Actinomycetes were isolated from chemical fertilizer and organic materials treated soils, and then grown on HV agar plate. The isolated strains were classified by Bergey's manual based on the morphological characteristics and color of substrate mycelium of actinomycetes. The number of actinomycetes increased 4 times in control, 36 times in clover, 20 times in straw, 5 times in chemical fertilizer and 4 times in commercial compost treated soil after 14th day of incubation. This result suggests that the application of straw or clover is more effective to increase the number of actinomycetes than compound fertilizer or commercial compost. It also showed that the application of chemical fertilizer or organic materials considerably changed the composition of soil actinomycetes flora. The proportion of streptomyces strains to the isolated total actinomycetes was 62% in control, 60% in clover, 68% in straw, 67% in chemical fertilizer and 64% in commercial compost treated soils at the 14th day.

• Journal of Soil and Groundwater Environment
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• v.29 no.1
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• pp.18-27
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• 2024

In this study, the pump and fertilize (PAF) was applied to reduce nitrogen infiltration into groundwater at three corn cultivation sites over a three-year period, and its effectiveness was evaluated. PAF involves pumping nitrate-contaminated groundwater and using it for irrigation, thereby replacing the need for chemical fertilizers. This method not only substitutes chemical fertilization, but also reduces nitrogen infiltration into groundwater through root zone consumption. To confirm PAF's effectiveness, an equal amount of nitrogen was applied in each cultivation plot, either through chemical fertilizer or irrigation with nitrate-contaminated groundwater. Regular monitoring of infiltrating pore water and groundwater was conducted in each cultivation plot. The linear regression slope for nitrate concentration in the pore water after repeated application of PAF ranged from -3.527 to -8.3485 mg-N/L/yr, confirming that PAF can reduce nitrate concentration in the pore water. With an increasing proportion of PAF, the infiltrating nitrate mass in pore water was reduced by 42% compared to plots fertilized with chemical fertilizer. Additionally, the linear regression slope of nitrate concentration in groundwater was calculated as -2.2999 and -9.2456 mg-N/L/yr. Therefore, continuous application of PAF in rural areas is expected to significantly contribute to reducing nitrate concentration in groundwater.