• Journal of Life Science
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• v.24 no.4
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• pp.403-410
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• 2014

This study was conducted in organic certification soil for the comparison of heavy metals, nutrients, and irrigated water standards to certify a farm. It was carried out in 811 paddy fields of organic rice (Oryza sativa L.) cultivated at Goseong-Gun. The amounts of 8 heavy metals, Cd, Cu, As, Hg, Pb, $Cr^{6+}$, Zn, and Ni were found to be 0.05, 14.5, 1.08, 0.92, 10.7, 1.34, 35.9, and 22.2 mg $kg^{-1}$ in regular sequence in the organic paddy soil, and they were 0.32, 13.6, 1.01, 0.03, 10.4, 0.91, 42.4 and 22.5 mg $kg^{-1}$ in the non-pesticide paddy soil. In comparing organic and non-pesticide paddy soil with respect to the chemical characteristics of the soil, the average pH and the amount of organic matter, available phosphate and available silicate were 5.88 and 27.6 g $kg^{-1}$, 134.5 mg $kg^{-1}$, and 165.3 mg $kg^{-1}$, while they were 5.78 and 32.1 g $kg^{-1}$, 107.7 mg $kg^{-1}$, and 175.2 mg $kg^{-1}$, respectively. The amount of exchangeable cation $K^+$, $Ca^{2+}$, and $Mn^{2+}$ were 0.25, 5.20, and 1.04 cmol+ $kg^{-1}$ in organic paddy soil, while they were 0.38, 5.13, and 1.19 cmol+ $kg^{-1}$ in non-pesticide paddy soil. The pH, DO, BOD, COD and SS conditions of the irrigated water used in the organic paddy soil were found to be 7.23, 8.40, 2.80, 1.86, and 2.58 mg $l^{-1}$ and the condition of irrigated water used in the non-pesticide paddy soil were found to be 7.65, 9.16, 2.25, 4.11, and 4.00 mg $l^{-1}$, respectively. Based on these findings, we suggest that environmentally-friendly certificates in Korea have to unify organic and non-pesticide agro-products in an organic standard in food policy and control because there is no difference between soil and irrigated water standards in the two certifications.

• Korean Journal of Environmental Agriculture
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• v.39 no.1
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• pp.36-43
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• 2020

BACKGROUND: Wicheon watershed has the largest irrigation area among the mid-watershed of Nakdong river. However, no investigation of irrigation water quality has been conducted on the Wicheon watershed, which evaluates the effects on the soil quality and crop cultivation. Therefore, this study aims to provide various assessments of water quality of Wicheon watershed as the scientific basic data for efficient agricultural activities. METHODS AND RESULTS: Water sampling was performed in five locations of the first tributaries of Wicheon. Wicheon watershed showed clean water quality with very low organic matters and safe water quality from metals at all points of investigation. It was estimated that the natural chemical components of Wicheon watershed were originated from water-rock interaction in Gibbs diagram. All samples were concentrated in the type of Ca-HCO₃-Cl in the Piper diagram. The quality of irrigation water was evaluated with sodium adsorption ratio (SAR), residual sodium carbonate (RSC), permeability index (PI), and percent sodium (%Na). The values of these water quality indices were in the range of 0.37-0.67, -2.11--0.24, 41.13-84.52% and 11.28-21.84%, respectively, and were classified as good grades at all sites. CONCLUSION: The water quality of Wicheon watershed was very low in salt, indicating good irrigation water suitable for growing agricultural products. We hope that the results of this study will be used as the basic data for the cultivation of agricultural products and promotion of their excellence.

• Korean Journal of Environmental Biology
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• v.17 no.1
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• pp.35-50
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• 1999

The relationship between floristic composition and soil environmental conditions was investigated in the forest vegetation of Mt. Paekun. The forest vegetation unit of Mt. Paekun was divided into six plant communities by Zurich-Montpellier method, such as Quercus mongelica community (Typical subcommunity, Rhododendron schlippenbaohii subcommunity), Q. variabilis community, Fraxinus rhynchophylla community, Pinus densiflora community, Larix Eeptolepis community and Pinus koraiensis community. Q. mongolica community group was distributed at the altitude over 500 meter, Q. variabilis and P. densiflora communities appeared on the southwestern slope at the altitudes of 600 ~ 700 m and 290 ~ 700 m. However, L. leptolepis and P. koraiensis plantation were distributed at lower altitude, on hillside or around homestead. The DBH class distribution of dominant species in each community showed that Q. mongolica had 10.9 individuals/a at 6~10 cm class, Q. variabilis 2.5 individuals/a at 11~15 cm class, P. densiflora 1.8 individuals/a at 26~30 cm class, F. rhynchophylla 3.3 individuals/a at 2~5 cm class, and L. leptolepis 5.9 individuals/a at 11~ 15 cm class. Q. mongolica and Q. variabilis communities showed a stable bell-shaped pattern of distribution. The contents of organic matters and soil water, and cation exchange capacity of the soil increased, and the pH decreased as the altitude gets higher increased altitude at the each communities. The contents of the soil water and organic matters of the forest soil collected in Q. mongolica community were in the 17.81% to 51.20% and 5.51% to 14.90%, respectively. These tendency is similar to the contents of N, P and K, but those of Ca, Mg, and CEC was lower than in other communities. Cation exchange capacity was suspected to be correlated to the pH. The hypothetical successional sere of the forest vegetation of Mt. Paekun is as follows: Pinus densiflora community longrightarrowQ. variabilis community longrightarrowQ. mongolica community.

• Journal of Korean Society of Water and Wastewater
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• v.28 no.6
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• pp.623-634
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• 2014

This study examined a feasibility of coagulation as post-treatment to remove sulfide and phosphorus for the effluent of anaerobic fluidized bed reactor (AFBR) treating domestic wastewater. Removal efficiencies of sulfide, phosphorus and COD by coagulation were not affected by pH in the range of 5.9 to 7.2. Alkalinity requirement could be estimated by the amount of $Fe^{3+}$ to form $Fe(OH)_{3(S)}$ and to remove sulfide and phosphorus. At coagulant aid dosage of 2 mg/L, anionic polymer showed best results regarding size and settleability of flocs. Sulfide removal for the AFBR effluent at the $Fe^{3+}/S^{2-}$ ratio of 0.64, close to the theoretical value of 0.67 found with a synthetic wastewater, was only 75.2%. One of the reasons for this high $Fe^{3+}/S^{2-}$ ratio requirement is that the AFBR effluent contains sulfide, phosphorus, hydroxide and bicarbonate which can react with $Fe^{3+}$ competitively. Concentrations of sulfide and phosphorous reduced to below 0.1 and 0.5 mg/L, respectively, at the $Fe^{3+}/S^{2-}$ ratio of 2.0. Average effluent COD of 80 mg/L, mostly soluble COD, was obtained at the dosage 50 mg $Fe^{3+}/L$ ($Fe^{3+}/S^{2-}$ ratio of 2.0) with corresponding COD removal of 55%. For better removal of COD, soluble COD removal at the AFBR should be enhanced. Coagulation with $Fe^{3+}$ removed sulfide, phosphorus and COD simultaneously in the AFBR effluent, and thus could be an alternative process for the conventional wastewater treatment processes where relatively high quality effluent is not required.

• Journal of the Mineralogical Society of Korea
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• v.22 no.3
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• pp.229-240
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• 2009

In Gosung, the symptoms similar to itai-itai disease from neighboring residents of the Samsanjeil mine have been social issues. Therefore, various researches on the behavior of heavy metals of the tailings impoundment of 280,000 ton in the Samsanjeil mine are required. In this paper, mineralogical and geochemical studies on the tailings at different depths in the Samsanjeil mine were investigated and the factors on the behavior of heavy metals were also studied. At two sampling sites (NN and SN), samples were collected at different depths down to 1 m. At NN sites, pH values decreased with depth, while those at SN sites did not show significant changes. XRD analysis showed that the main minerals in the tailings were quartz, microcline, muscovite, and chlorite with minor amount of gypsum. There were no noticeable changes in the mineral composition with depth. At NN sites, the amount of calcite was negligible, and jarosite, which usually occurs at acid soil or acid mine drainage at pH lower than 4, was identified. However, the samples at SN site contained relatively high contents of calcite with pyrite. Therefore, calcite seemed to buffer the acid and control pH at SN site. The contents of heavy metals in tailings were in the order of Cu > As > Zn > Pb > Co > Cr > Ni > Cd. The heavy metal concentrations in the tailings were closely related with pH changes. The concentrations of Cd and Co were much lower at NN site at which pH values are low than those at SN sites. Contrary to that, Cr and As which exist as oxyanions showed higher concentrations at SN sites. This result showed that the behaviors of heavy metals in our study area were controlled by pH which is influenced by the contents of calcite.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.65 no.1
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• pp.72-78
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• 2020

In this study, miscanthus with C/N ratio of 224 were applied to the soil and treated with 0 (control), 10 tons and 20 tons·ha^-1 to improve the soil and promote crop growth. As a result, soil organic matter content increased from 11.0 g·kg^-1 before the test to 16.3 after 3 years. Soil cation exchangeable capacity increased to 15.3 cmol_c·kg^-1 after 3 years. In the sweet sorghum, stem was the most thickest at 20 tons·ha^-1 application of miscanthus and the highest juice amount per plant was 60 ml. The yield index multiplied by the soluble solids content of juice and juice amount was the highest at 1,913 for 10 tons application and 1,851, 1,839 for 20 tons, control respectively. Number of sweetpotato storage root were 2,9 in 20-tons application plot, the same as control, and 10-tons application plot was 3.6, the most. Two-year average yields of 20 tons plot and control were low at 2,579 kg/10a and 2,708 respectively, and 10 tons plot was the highest at 3,289. For onions, the biomass application did not effect the yield. but onion plant and leaf length were longer in 20 tons plot than in control or 10 tons. The yield of garlic was 2,630~2,901 kg/10a and there was no effect of miscanthus application. Plot of 10 tons application were the longest in plant and leaf length, and the number of scale was 8.2-8.3 per in bulb, and 8.9 tons·ha^-1 in control. Therefore, it was confirmed the possibility that miscanthus biomass application of about 10 tons·ha^-1 could improve the soil condition and promote crops growth and yield.

• Journal of The Korean Society of Grassland and Forage Science
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• v.22 no.1
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• pp.69-76
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• 2002

This pot experiment was conducted to find out the forage productivity and contents of mineral nutrients in an orchardgrass sward as affected by the compost lime, and phosphorus applications on the newly reclaimed and arable pasture soils. This 1st part was concerned with the effect of compost application. The results obtained are summarized as follows: 1. There were considerable differences between the newly reclaimed and arable pasture soils in the soil chemical properties as fellows(newly reclaimed soil ↔ arable pasture soil): poor ↔common in pH and contents of Ca and Mg; Poor ↔ good in content of available P$_2$O$_{5}$, base saturation, and mutual balance of Ca : Mg : K; common ↔ good in K content; good ↔ good in absorption coefficient of P$_2$O$_{5}$; poor ↔ somewhat poor in CEC. The contents of available P$_2$O$_{5}$ in both soils after experiment were relatively higher in the compost block than non-compost block. It was recognized that the compost application was resulted in the CEC increase in the newly reclaimed soil. 2. The vigour at early growth of orchardgrass was better in the arable pasture soil then newly reclaimed soil. In the newly reclaimed soil, the vigour at early growth of orchardgrass was remarkedly enhanced by compost application. 3. Under the non-compost application, the orchardgrass yield was higher in the arable pasture soil by 50.9% than newly reclaimed soil. Compared with the non-compost application, the orchardgrass yields were increased in the newly reclaimed soil by 17.1% and the arable pasture soil by 7.6% by the compost application. 4. The concentrations of Ca, Mg, and P in orchardgrass were relatively higher in the arable pasture soil than the newly reclaimed soil, whereas there was no difference in the K concentration. It was recognized that the concentrations of Mg and P in orchardgrass were higher in the compost block than the non-compost block.block.

• Journal of The Korean Society of Grassland and Forage Science
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• v.29 no.4
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• pp.337-344
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• 2009

This study was conducted to investigate the effects of various cropping system applied with cattle slurry on productivity of sorghum $\times$ sudangrass hybrid (SSH) and environmental pollution in paddy land. cropping systems used in this study were consisted of two designs, such as double-cropping sorghum $\times$ sudangrass hybrid followed by whole crop barley applied with cattle slurry (DSSCS) and mono-cropping sorghum $\times$ sudangrass hybrid followed by hairy vetch used as green manure (MSSGM). The field experiments were conducted on the clay loam at Backsanmyun, Kimje, Chunlabukdo province in Korea for three years (May 2006 to Apr. 2009). This study was arranged in completely randomized design with three replicates. The yield of dry matter (DM) of SSH in DSSCS increased significantly as compared with that of MSSGM (P<0.05). The contents of crude protein (CP), acid detergent fiber (ADF), neutral detergent fiber (NDF) and total digestible nutrients (TDN) of SSH were not influenced by cattle slurry and green manure. The pH, and contents of OM, T-N and $P_2O_5$ in soil samples collected from DSSCS after the end of experiment were higher than those of MSSGM. The pH, and contents of OM in DSSCS treatment were remarkably higher than those at the beginning of the experiment (p<0.05). However, The pH, and contents of OM in MSSGM treatment were hardly influenced, as compared with those at the beginning of the experiment. The contents of T-N in soil samples collected both from DSSCS snd MSSGM treatments were remarkably higher than those at the beginning of the experiment (p<0.05). In addition, the concentrations of CEC in soil samples collected at the end of the experiment were remarkably higher than those at the beginning of the experiment (p<0.05). The concentrations of $NO_3$-N, $NH_3$-N and $PO_4$-P in leaching water were hardly influenced by the cropping system and application of cattle slurry.

• Journal of Korean society of Dental Hygiene
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• v.2 no.2
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• pp.175-186
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• 2002

Fluoride has been one of the most widely studied caries-preventive agents. But the effect of prenatal administration had been controversies for many years. The results showed that there were no influence on reproductive rate of rats with administration of fluoride from 0 to 20 ppm during pregnancy(p>0.05). There was a trend towards slightly increased the mean ash weight in the 1, 5 and 20 ppm groups, as compared with the control group. However, there was no significant differences among groups (p>0.05). The contents of calcium, magnesium and phosphorus in the total bone were increased with the administrated fluoride concentration were increased, but there were no statistically significant differences among groups(p>0.05). The mean fluoride level of 1 ppm group was significantly higher than that of control group, but the concentrations of fluoride in total carcass pups of 5 and 20 ppm groups were significantly less than that of 1 ppm group(p>0.05). The results of this study indicate that the amount of fluoride transferred to the offspring, which may produce anticariogenic effects in the primary teeth of their effects in the primary teeth of their offspring.

• Economic and Environmental Geology
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• v.40 no.5
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• pp.587-604
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• 2007

In order to investigate the vertical variations and speciations of trace elements, and their correlations in Hoidong reservoir, sediment cores (21-41 cm below surface) and interstitial water samples were collected from five sampling locations. The total average concentrations of trace metals in sediment core samples were $232{\pm}30.8mg/kg$ for Zn, $119{\pm}272mg/kg$ for Cu, $58.4{\pm}4.1mg/kg$ for Pb, $15.7{\pm}3.3mg/kg$ for Ni and $1.6{\pm}0.3mg/kg$ for Cd. The total concentrations of trace metals in core sediments generally decreased toward the center of the Hoidong reservoir. The total concentrations of Mn, Pb and Zn decreased with depth for all the sample locations, while Cu and Fe concentrations increased. The trace metal concentrations of interstitial water sample were in the order of Fe>Mn>Cu>Zn, but Cd, Ni and Pb were not detected. The concentrations of Zn, Cu, Fe and Mn in the interstitial water samples showed a tendency of increasing toward the bottom of the core, suggesting a possible upward diffusion. This migration of trace metals may lead to their transfer to the sediment-water interface. These trace elements would be subsequently fixed onto amorphous Fe and Mn-oxides and carbonates in the topmost layer of sediment. Based on the $K_D$ values, the relative mobilities of the studied metals were in the order of Mn>Cu>Zn>Fe. Geochemical partitioning confirmed that surface enrichment by trace metals mainly resulted from a progressive increase of the concentrations in the fractions II and III. Copper, Fe, Mn and Zn concentrations of interstitial water were closely correlated with their exchangeable fractions of sediments.