• Korean Journal of Soil Science and Fertilizer
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• v.17 no.3
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• pp.232-241
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• 1984

For the purpose of investigating the effect of chemical composition of nitrogenous fertilizers such as urea, ammonium sulfate, ammonium phosphate(dibasic) and aqua-ammonia on growth, yield, efficiency and chemical properties of paddy soil this study was carried out at the same nitrogen concentration through field experiment. The results obtained was summarized as follows. 1. Nitrogenous fertilizers had an effect on plant height at heading stage, plant weight at harvest and No. of spikelet per panicle of rice plants in decreasing order: Ammonium sulfate > Diammonium phosphate > Urea > Ammonia water. But they didn't effect on culm length, spike length, dry matter weight, No. of grain per spike, ripening ratio and weight of 1000 grains of rice plants. 2. The absorbed amount of nitrogen and that of sulfur and nitrogen availability were highest in ammonium sulfate application and lowest in ammonia water application and these were positively correlated with yield. 3. The influence of nitrogenous fertilizers on nitrogen and sulfur efficiency and translocation efficiency was insignificant but that of ammonium sulfate on nitrogen efficiency was higher than that of the others. 4. The effect of nitrogenous fertilizers on a basic chemical properties of paddy soil experimented such as pH, C.E.C, exchangeable cation and organic matter was insignificant. But the sulfur content of ammonium sulfate application and phosphorous content of diammonium phosphate application were higher than that of the others.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.3
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• pp.393-398
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• 2012

We investigated the changes in chemical properties of paddy field soils at 300 different sampling sites containing 4 topography in Jeonbuk province, Korea. The soil samples were collected 43.0% from local valley and fans, 39.3% from fluvio-marine deposits, 15.0% from alluvial plains, and 2.7% from diluvium sites. The optimal values of soil properties in the total soil samples were as follows: 65.3% of total samples in soil pH value, 48.3% of total samples in cation exchange capacity (CEC) value, and 22.3% of total samples in available phosphorus content, whereas the deficient values of soil properties were 63.3% of total samples in soil organic matter (SOM) content, 75.7% of total samples in available silicate content, and 61.3%, 51.0%, and 59.3% of total samples in exchangeable $K^+$, $Ca^{2+}$, and $Mg^{2+}$ concentrations, respectively. There were different soil types in the paddy fields: that is, 34.4% immature paddy and 33.6% sandy paddy in the local valley and fans, 57.8% sandy paddy in the alluvial plains, 47.4% normal paddy in the fluvio-marine deposits, and 75.7% immature paddy in the diluvium. Soil textures were also different: 53.5% loam in the local valley and fans, 37.8% sandy loam in the alluvial plains, and 55.1% silty loam in the fluvio-marine deposits. Soil pH and SOM contents were not different among the different topographical sampling sites. However, the mean value of available phosphorus content, 224 mg $kg^{-1}$, was exceeded optimal values in the diluvium. The contents of exchangeable cations were optimal in all the sites, except exchangeable $Ca^{2+}$ contents in the local valley and fans. The contents of available silicate ranged between 112 and 127 mg $kg^{-1}$ in all the sites, which were lower than optimal value. In addition, soil pH values were proportionally correlated to the order of available silicate, exchangeable $Ca^{2+}$, $Mg^{2+}$, $Na^+$, CEC, and exchangeable $K^+$. The contents of SOM were proportionally correlated to the order of CEC, available $P_2O_5$, exchangeable $Ca^{2+}$, and available silicate. The contents of heavy metals, Cd, Cr, Cu, Ni, Pb, and Zn, were only 10% of the threshold levels of the metals, and As content was about 20 to 30% of the threshold level.

• Journal of Korean Society of Forest Science
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• v.46 no.1
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• pp.10-20
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• 1980

This experiment was carried out to investigate the effects of physico-chemical properties of soil on the growth of Chamaecyparis obtusa and to apply the results to such rational forest management as yield forecast and selection of suitable species for a given forest stand. The soil properties observed in this experiment were soil pH, exchangeable pH organic matter, total nitrogen, available $P_2O_5$, cation exchange capacity, exchangeable $H^+$, total base and base saturation. Diameter at breast height (DBH), height and volume growth of C. obtusa were observed at 78 sampling sites. Data were processed into the following series for the analysis of multivariates : inner correlation matrix, multiple correlation coefficients, regression coefficients and partial correlation coefficients. The results are summerized as follows : 1. Multiple correlation coefficients between soil properties and DBH of C. obtusa were .364 for 20-year trees, resulting less efficient for estimating the growth of C. obtusa. However, total base, soil pH and base saturation were considerable characters for better estimation. 2. More efficient multiple correlation coefficients were observed between soil properties and height growth than those between soil properties and DBH, showing .443 for 20-year trees and factors affecting the height growth were similar to those of DBH. 3. Extremely low values of multiple correlation coefficients were estimated between physico-chemical properties of soil and volume growth of C. obtusa resulting low efficient estimation. However, total base contributed highly to volume growth of C. obtusa. Accordingly the most contributable factor for estimating the growth of C. obtusa were total base, soil pH and base saturation. Consequently, these results can be effective for selecting of the reforesting site, and less effective for estimating the growth of C. obtusa.

• Korean Journal of Environment and Ecology
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• v.28 no.3
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• pp.342-356
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• 2014

This study aims to provide the fundamental data for restoration through the analysis of vegetation structure characteristic for managed area with deforest and fumigation among the places damaged by oak wilt disease in Bukhansan National Park. Study areas were selected in six damaged areas with 18 plots ($20m{\times}20m$) including comparing plots between year 2006 and year 2011 after preliminary study finding the exact location with easy access. Analysis items are density and coverage of under story layer, Importance Percentage of under story layer and Importance Percentage of urban adapted species and alien species. As a result, density and coverage under the canopy layer's vegetation was higher than comparing plot in Musugol valley and Soquicheon valley which 4 years and more passed. And Wondobong, Darakwon, Doseonsa and Dobong valley which had not been passed 3 years after deforestation and fumigation decreased in those of vegetation. However, the plots in Wondobong and Doseonsa was analyzed to be higher in density of shrubs than comparing plot. In terms of distirbution of species in under canopy layer which is grown as a upper vegetation, Quercus serrata and Sorbus alnifolia dominated each other in under canopy layer except for Wondobong and Darakwon. Wondobong continuously maintained Quercus mongolica and Q. mongolica and Pinus densiflora dominated in under canopy layer of Darakwon. S. alnifolia which is Urban adapted species were distributed in most study areas. In terms of alien species, Magnolia obovata and Robinia pseudoacacia were newly intruded in the opened crown, and Pueraria thunbergiana was distributed in Soquicheon valley. As the result of soil analysis, acidification(pH 4.49) and low level of organic matter(3.23%), available phosphate(1.40mg/kg) and exchangeable cation were analyzed and it was considered that those environment poorly support the vegetation growth.

• Korean Journal of Environmental Agriculture
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• v.18 no.2
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• pp.164-168
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• 1999

For investigating transfer factors of $^{137}Cs$ in the arable land of Korea, mature crop plants and topsoils were collected from paddy and upland fields located at 33 areas of the country and $^{137}Cs$ concentrations were measured by ${\gamma}-spectrometry$. The $^{137}Cs$ concentrations in soil were in the range of $0.7{\sim}17.7$ Bq/kg-dry in the paddy fields and $1.2{\sim}27.8$ Bq/kg-dry in the upland fields. The $^{137}Cs$concentrations in hulled seed, detected for 12 areas only, were in the range of $0.019{\sim}0.111$ Bq/kg-dry and those in Chinese cabbage, detected also for 12 areas only, were in the range of $0.012{\sim}0.066$ Bq/kg-fresh. Soil-to-plant transfer factors of $^{137}Cs$ were in the range of $1.2{\times}10^{-3}{\sim}1.1{\times}10^{-2}$ for hulled seed and $6.8{\times}10^{-4}{\sim}1.7{\times}10^{-2}$ for Chinese cabbage. Inboth plant stuffs, the factor tended to decrease with increasing soil organic matter or cation exchange capacity and, in hulled seed, it tended to increase with increasing soil clay content. No statistical significance was, however, found in all those relationships. Present results can be utilized for estimating radiation risk resulting from the food consumption by Korean people and deciding agronomical counter-measures at the time of an nuclear accident.

• Korean Journal of Soil Science and Fertilizer
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• v.34 no.6
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• pp.373-379
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• 2001

The weathering rates and change of chemical composition of 6 residual Entisols derived from granite, granite-gneiss, limestone, sandstone, shale, amd basalt in Korea were studied. The chemical composition of each profile with parent rocks were determined using XRF with the physico-chemical properties and the morphology of soils. In the A horizons of all the soils except Euiseong series, the content of clay, organic matter and cation exchange capacity(CEC) showed higher than those of C horizon, but bulk density and pH showed lower than C horizon. Clay content in the soil from sandstone was decrease with soil depth, which may caused by the elluriation. In total element analysis. $SiO_2$ was high in the soil from granite. granite-gneiss, sandstone and compare with basalt and limestone. $Fe_2O_3$ and MgO was high in the soil from basalt, limestone and shale compare with granite. granite-gneiss and sandstone. And ignition loss was particularly high in the soil from basalt and limestone. The rate of element loss was higher in base cations(Ca, K, Mg, Na) than Si, Al, Fe in the soils. The concentrations of $TiO_2$ in the A horizon compare with that of the C horizon was due to resulting from losses of other less stable elements existed. Considering with relative rate of each elements in soils, $SiO_2$ and $Al_2O_3$ which originated from sandstone and granite, granite-gneiss, sandstone, shale, and basalt were lost higher than those from lime tone, but loss of basic cations were more in the soil from limestone which may be rapid weathering of calcite. The magnitude of losses of the overall elements were increased in the order of the soils from sandstone and granite ${\gg}$ limestone and shale) granite-gneiss and basalt.

• Korean Journal of Soil Science and Fertilizer
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• v.32 no.3
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• pp.232-238
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• 1999

Effects of animal manure application on the yield of crops were studied. Red pepper (1995) and Chinese cabbage (1996) were planted in pot with chicken, cow and pig manure application at $1.6mg\;ha^{-1}$, $3.2mg\;ha^{-1}$. Silage corn was grown in pot at 100%, 75%, 50% and 0%of recommended chemical fertilization rate among previously manure applied soils to predict the reduction of fertilizer. Results were as follows: Chemical properties of manure applied soils for two years were increased as pH 6.1~7.1, OM $17.1{\sim}23.7g\;kg^{-1}$, $P_2O_5$ $370{\sim}1.058mg\;kg^{-1}$, while those of chemical fertilizer applied soils were pH 5.8. OM $16.9g\;kg^{-1}$, $P_2O_5$ $249mg\;kg^{-1}$. Exchangeable cation and $P_2O_5$ content were increased in chicken manure applied soils than those in manure applied soils. Red pepper yield in manure applied pots was 121~192% compared to that in only chemical fertilizer applied pot. Effects of manure application was in the order of pig, chicken and cow manure. Chinese cabbage yield in manure applied pots was 55%~111% compared to that in chemical fertilizer applied pot. Effects of manure application were higher in red pepper than in Chinese cabbage. Fresh corn yield showed no significance between reducing 0% and 25% of recommend fertilization rate in previously manure applied plots, except in previously cow manure applied plots at $1.6mg\;ha^{-1}$. Fresh corn yield showed a positive correlation ($r=0.75^{**}$) with organic matter content and showed a positive correlation ($r=0.85^{**}$) with total nitrogen in untreated plot among previously manure applied soils.

• Journal of the Mineralogical Society of Korea
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• v.21 no.3
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• pp.313-320
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• 2008

Hectorite was synthesized under hydrothermal conditions and its physicochemical properties have been investigated in terms of temperature, pH, and organic agent to observe the change of doll basal spacing. The IR, CEC, MB, swelling volume and specific surface area of the hectorite were measured for the characterization. The solid/liquid ratio of hectorite to distilled water before mixing with other materials was also determined for its use as a multi-functional material. The $d_{001}$ basal spacing decreased from $12.63\;\AA$ at room temperature to $10.19\;\AA$ at $650^{\circ}C$ in the heating tests. As the pH of hectorite slurry increased. the $d_{001}$ basal spacing decreased. reaching the lowest value of $13.33\;\AA$ at pH 7 and afterward, increased. All the fool basal spacings of the hectorite increased when it was intercalated with the following solvents: $12.86\;\AA$ in diethyl ether, $13.31\;\AA$ in acetonitrile. $13.59\;\AA$ in methanol, $14.05\;\AA$ in ethanol, $15.69\;\AA$ in acetone, and $17.42\;\AA$ in ethylene glycol. Our IR analysis results were in good agreement with those of other researchers. The CEC, MB, swelling volume and specific surface area of hectorite were determined to be 105 cmol/kg, 80 cmol/kg, $68\sim74ml/2g$ and $213m^{2}/g$, respectively. Also, the hectorite to distilled water ratio of 2 to 100 was found to be most favorable for mixing with other materials such as the solvents mentioned above.

• Korean Journal of Poultry Science
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• v.40 no.2
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• pp.97-103
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• 2013

The present study examined effects of production performance, immune activity and egg quality by raising on exercise yard in laying Hens, the results of which could be used as baseline data to enhance animal welfare and the safety of livestock products. A total of 90 Hy-line-Brown laying hens of 13 weeks old were used in the experiment for 38 weeks. The cage group (Cage group) was raised in a cage, where an area of $0.084m^2$ was assigned to two hens, while hens in the exercise yard $1.1m^2$ group ($1.1m^2$ group) was assigned to a combination of a chicken house ($0.11m^2$) and a exercise yard ($1.1m^2$) per a hen. Hens in the exercise yard $2.2m^2$ group ($2.2m^2$ group) was assigned to a combination of a chicken house ($0.11m^2$) and a exercise yard ($2.2m^2$) per a hen. Treatment was replicated 3 times with ten birds per replication. Ten birds were arranged according to randomized block design. While initial egg production rate was significantly higher in the Cage group, $1.1m^2$ group exhibited a slightly higher rate in the mid- and late-stage of the experiment, although the difference was not statistically significant. Exercise yard treatment groups exhibited a higher feed intake rate than the Cage group up until the hens were 39 weeks old (P<0.05), but the difference dissipated from that age on. The age at first egg in the exercise yard treatment groups was 16 days later than that for the Cage group (P<0.05), although differences in the quality of the eggs were not observed. The results of immune activity test showed that IgA in the exercise yard treatment groups was significantly higher than that in the Cage group (P<0.05). IgG, IgM, and corticosterone were also higher in the exercise yard treatment groups. The soil in exercise yard increased of organic matter and decreased of cation exchange capacity (CEC) in raised hens. In sum, raising hens in a exercise yard raise style decreased the rate of initial egg production, which was followed by a slight increase during the latter part of the experiment. The exercise yard raise hens' immune activity was heightened.

• Journal of Soil and Groundwater Environment
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• v.13 no.5
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• pp.8-19
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• 2008

The physicochemical properties of soils having high uranium content, located around Duckpyungri in Korea, were investigated and the lab scale soil washing experiments to remove uranium from the soil were preformed with several washing solutions and on various washing conditions. SPLP (Synthetic Precipitation Leaching Procedure), TCLP (Toxicity Characteristic Leaching Procedure), and SEP (Sequential Extraction Procedure) for the soil were conducted and the uranium concentration of the extracted solution in SPLP was higher than Drinking Water Limit of USEPA (30 ${\mu}g$/L), suggesting that the continuous dissolution of uranium from soil by the weak acid rain may generate the environmental pollution around the research area. For the soil washing experiments, the uranium removal efficiency of pH 1 solution for S2 soil was about 80 %, but dramatically decreased as pH of solution was > 2, suggesting that strong acidic solutions are available to remove uranium from the soil. For solutions with 0.1M of HCl and 0.05 M of ${H_2}{SO_4}$, their removal efficiencies at 1 : 1 of soil vs. washing solution ratio were higher than 70%, but the removal efficiencies of acetic acid, and EDTA were below 30%. At 1 : 3 of soil vs. solution, the uranium removal efficiencies of 0.1M HCl, 0.05 M ${H_2}{SO_4}$, and 0.5M citric acid solution increased to 88%, 100%, and 61% respectively. On appropriate washing conditions for S2 soil such as 1 : 3 ratio for the soil vs. solution ratio, 30 minute for washing time, and 2 times continuous washing, TOC (Total Organic Contents) and CEC (Cation Exchange Capacity) for S2 soil were measured before/after soil washing and their XRD (X-Ray Diffraction) and XRF (X-Ray Fluorescence) results were also compared to investigate the change of soil properties after soil washing. TOC and CEC decreased by 55% and 66%, compared to those initial values of S2 soil, suggesting that the soil reclaimant may need to improve the washed soils for the cultivated plants. Results of XRF and XRD showed that the structural change of soil after soil washing was insignificant and the washed soil will be partially used for the further purpose.