• Korean Journal of Organic Agriculture
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• v.16 no.1
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• pp.115-125
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• 2008

This study was conducted to determine adequate forage crop choice and optimal level of livestock manure, when different types and levels of the livestock manure were applied in corns or sorghum$\times$sorghum hybrids for the production of organic roughages by utilizing livestock manure. For the corn, yields of annual dry matter (DM) and total digestible nutrients (TDN) were highest in N+P+K-applied treatments, showing 17.3 and 11.7 ton/ha, respectively. Treatments applied 100% composted cattle manure (8.9 and 6.1 ton/ha) and 100% cattle slurry (9.4 and 7.5 ton/ ha) in contrast with chemical fertilizer-N had higher yields of DM and TDN than no fertilizer (4.8 and 2.7 ton/ha) and P+K-applied treatments (8.8 and 6.0 ton/ha). Particularly, treatments applied 150% composted cattle manure and 150% cattle slurry were markedly higher, which represented 11.4 and 7.6 ton/ha and 10.3 and 7.3 ton/ha, respectively. Crude protein (CP) contents for corns applied livestock manure ranged from 5.6 to 6.6%, which were significantly (p<0.05) higher than those of no fertilizer (3.9%) and P+K-applied treatments (5.5%). ADF (42.4%) and NDF (58.3%) contents for no fertilizer treatment were significantly (p<0.05) higher than those of other treatments. However, TDN contents were higher for livestock manure treatments than for no and/or chemical fertilizer treatments. In particular, TDN contents of treatments applied 150% composted cattle manure and 150% cattle slurry showed 72.3 and 70.8%, respectively and both treatments were significantly (p<0.05) higher than all of the other treatments. For the sorghum$\times$sorghum hybrid, yields of annual DM and TDN for 100% (12.4 and 7.4 ton/ha) and 150% (13.1 and 7.6 ton/ha) cattle slurry-applied treatments, and N+P+K-applied treatments (12.6 and 7.7 ton/ha) were significantly (p<0.05) higher than those of the others. In the others, 150% composted cattle manure (9.3 and 5.2 ton/ha) had higher annual DM and TDN yields than P+K-applied (8.4 and 4.8 ton/ha) and 100% composted cattle manure treatments (7.4 and 4.2 ton/ha), with no significant difference. Crude protein contents for sorghum$\times$sorghum hybrid applied P+K and cattle slurry were 8.8 and 8.6%, respectively. CP contents for both treatments were significantly higher than those of composted manure ($7.5{\sim}8.3%$) and no fertilizer (4.0%) treatments, but 100% livestock manure treatments had higher CP contents than 150%-applied treatments. ADF and NDF contents for N+P+K and cattle slurry-applied treatments were significantly (p<0.05) lower than the others. However, TDN contents were highest in N+P+K and cattle slurry-applied treatments, showing 61.2 and 58.3 to 59.4%, respectively. These results indicated that application of livestock manure instead of chemical fertilizer to the soil of forage crops might not only improve yields of DM and TDN, but also reduce environmental pollution by producing organic roughages through recycling of livestock manure.

• Korean Journal of Environmental Agriculture
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• v.30 no.1
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• pp.24-30
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• 2011

BACKGROUND: High input to the arable land is contributed to increasing productivity with causing the global environmental problems at the same time. Rapeseed cultivation has been forced to reassess its positive point for utilization of winter fallow field. The Objective of this study was performed to assess the environmental impact of rapeseed cultivation with double-cropping system in paddy rice on Yeonggwang district using life cycle assessment technique. METHODS AND RESULTS: For assessing each stage of rapeseed cultivation, it was collected raw data for input materials as fertilizer and pesticide and energy consumption rate by analyzing the type of agricultural machinery and working hours by 1 ton rapeseed as functional unit. Environmental impacts were evaluated by using Eco-indicator 95 method for 8 impact categories. It was estimated that 216 kg $CO_2$-eq. for greenhouse gas, 3.98E-05 kg CFC-11-eq. for ozone lazer depletion, 1.78 kg SO2-eq. for acidification, 0.28 kg $PO_4$-eq. for eutrophication, 5.23E-03 kg Pb-eq. for heavy metals, 2.51E-05 kg B(a)p-eq. for carcinogens, 1.24 kg SPM-eq. for smog and 6,460 MJ LHV for energy resource are potentially emitted to produce 1 ton rapeseed during its whole cultivation period, respectively. It was considered that 90% of these potential came from chemical fertilizer. For the sensitivity analysis, by increasing the productivity of rapeseed by 1 ton per ha, potential environmental loading was reduced at 22%. CONCLUSION(s): Fertilization affected most dominantly to the environmental burden, originated from the preuse stage, i.e. fertilizer manufacturing and transporting. It should be included and assessed an indirect emission, which is not directly emitted from agricultural activities. Recycling resource in agriculture with reducing chemical fertilizer and breeding the high productive variety might be contribute to reduce the environmental loading for the rapeseed cultivation.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.2
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• pp.160-165
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• 2010

To reduce the dose of fertilizers is very important to sustainable production of many horticultural crops, including strawberry. In order to practice the environment friendly agriculture of strawberry cultivation in plastic film house, soil chemical properties of 435 soil samples (232 for loam, 83 for sandy loam, and 120 for silt loam) in Chungnam Province from2008 to 2009 were determined. The average of pH, EC, OM, Av. $P_2O_5$, Ex. $K^+$, Ex. $Ca^{2+}$, Ex. $Mg^{2+}$, and Ex. $Na^+$ was 6.5, 2.28 dS $m^{-1}$, 26 g $kg^{-1}$, 910 mg $kg^{-1}$, 1.09 $cmol_c\;kg^{-1}$, 8.3 $cmol_c\;kg^{-1}$, 2.5 $cmol_c\;kg^{-1}$, and 0.58 $cmol_c\;kg^{-1}$, respectively. The content of Av. $P_2O_5$ in sandy loam soil was significantly higher than silt loam soil, whereas other properties showed no difference between soil texture. The kinds of strawberry cultivars showed no difference in soil chemical properties. The frequency distribution within optimum range of soil chemical properties was 30.6%, 35.4%, 37.0%, 5.3%, 8.5%, 8.5%, and 17.9% for pH, EC, OM, Av. $P_2O_5$, Ex. $K^+$, Ex. $Ca^{2+}$, and Ex. $Mg^{2+}$, respectively. Especially, excessive portion of Av. $P_2O_5$, and Ex. $Ca^{2+}$ were high 86.9%, and 86.0%, respectively. EC values of soil samples were significantly positive correlatoin with all chemical properties except soil pH. In principle component analysis of chemical properties in soil samples, the percentage of variance explained by PC 1 was 38.8%, while PC 2 explained 17.8%of the variance, for a cumulative total of 56.6%. These results were able to distinguish between soil textures and strawberry cultivars. Also, these results considered that understanding of soil chemical properties under using principal component analysis be able to improve amounts of fertilizers for sustainable agriculture in plastic film house.

• Journal of Korean Society of Environmental Engineers
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• v.29 no.6
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• pp.715-721
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• 2007

Residual calcium concentration is high, in general, at the effluent of the fluoride removal process in the electronics industry manufacturing semiconductor and LCD. To increase the stability of the membrane process incorporated for reuse of wastewater, the residual calcium is required to be pre-removed. Hyperkinetic Vortex Crystallization(HVC) process was installed in the electronics industry manufecturing semi conductor as a pilot scale for accelerating calcification of calcium ion. Compared to the conventional soda ash method, the 31% higher calcium removal efficiency was achieved when HVC was applied at the same sodium carbonate dosage. In order to maintain the economic calcium removal target of 70% preset by manufacturer, the dosing concentration of the soda ash was 530 mg/L based on influent flowrate. The seed concentration in the reactor was one of the critical factors and should be maintained in the range of $800\sim1,200mg$ SS/L to maximize the calcium removal efficiency. The calcite production rate was 0.30 g SS/g $Na_2CO_3$ in the average. The economic HVC passing time of the mixture was in the range of $2\sim5$ times. Relatively, stable calcium concentration was maintained in the range of $30\sim72$ mg/L(average 49 mg/L) although the calcium concentration in the feed was severely fluctuated with $74\sim359$ mg/L(average 173 mg/L). The HVC process was characterized as environment-friendly technology reducing chemical dosage and chemical sludge production and minimizing maintenance cost.

• Korean Journal of Environmental Biology
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• v.40 no.3
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• pp.267-274
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• 2022

Excess nitrogen (N) flowing from livestock manure to water systems poses a serious threat to the natural environment. Thus, livestock wastewater management has recently drawn attention to this related field. This study first attempted to obtain the optimal conditions for the further volatilization of NH₃ gas generated from pig wastewater by adjusting the amount of injected magnesia (MgO). At 0.8 wt.% of MgO (by pig wastewater weight), the volatility rate of NH₃ increased to 75.5% after a day of aeration compared to untreated samples (pig wastewater itself). This phenomenon was attributed to increases in the pH of pig wastewater as MgO dissolved in it, increasing the volatilization efficiency of NH₃. The initial pH of pig wastewater was 8.4, and the pH was 9.2 when MgO was added up to 0.8 wt.%. Second, the residual ammonia nitrogen (NH₄⁺-N) in pig wastewater was removed by precipitation in the form of struvite (NH₄MgPO₄·6H₂O) by adjusting the pH after adding MgO and H₃PO₄. Struvite produced in the pig wastewater was identified by field emission scanning electron microscopy (FE-SEM) and X-ray diffraction (XRD) analysis. White precipitates began to form at pH 6, and the higher the pH, the lower the concentration of NH₄⁺-N in pig wastewater. Of the total 86.1% of NH₄⁺-N removed, 62.4% was achieved at pH 6, which was the highest removal rate. Furthermore, how struvite changes with pH was investigated. Under conditions of pH 11 or higher, the synthesized struvite was completely decomposed. The yield of struvite in the precipitate was determined to be between 68% and 84% through a variety of analyses.

• Korean Journal of Organic Agriculture
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• v.16 no.4
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• pp.421-434
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• 2008

This study was carried out to estimate the selection of appropriate forage crops, proper application levels of livestock manure, and carrying capacity per unit area for organic livestock, as influenced by livestock manure application levels compared with chemical fertilizer to corn and sorghum $\times$ sorghum hybrid, in order to produce organic forages by utilizing livestock manure. For both corns and sorghum $\times$ sorghum hybrids, no fertilizer plots had significantly (p<0.05) lower annual dry matter (DM), crude protein (CP) and total digestible nutrients (TDN) yields than those of other plots, whereas the N+P+K plots ranked the highest yields, followed by 150% cattle manure plots and 100% cattle manure plots. Dry matter, CP and TDN yields of cattle manure plots were significantly (p<0.05) higher than those of no fertilizer and P+K plots. In applying cattle manure, the yields of cattle slurry plots tended to be a little higher than those of composted cattle manure plots. Assuming that corns and sorghum $\times$ sorghum hybrids produced from this trial were fed at 70% level to 450kg of Hanwoo heifer with 400g of average daily gain, livestock carrying capacity (head/year/ha) ranked the highest in N+P+K plots of the case of corns (mean 6.7 heads), followed by 150% cattle slurry plots (mean 5.6 heads), 150% composted cattle manure plots (mean 4.8 heads), 100% cattle slurry plots (mean 4.4 heads), 100% composted cattle manure plots (mean 4.3 heads), P+K plots (mean 4.1 heads), and no fertilizer plots (mean 3.1 heads). Meanwhile, in case of sorghum $\times$ sorghum hybrids, N+P+K plots (mean 5.7 heads) ranked the highest carrying capacity, followed by $100{\sim}150%$ cattle slurry plots (mean $4.8{\sim}5.2$ heads), 150% composted cattle manure plots (mean 4.7 heads), 100 % composted cattle manure plots (mean 4.3 heads), P+K plots (mean 3.8 heads), and no fertilizer plots (mean 3.4 heads). The results indicated that replacing chemical fertilizer by livestock manure application to cultivation soil for forage crops could enhance not only DM and TDN yields, but also organic stock carrying capacity. In conclusion, it was conceived that organic forage production by reutilizing livestock manure might contribute to reduced environmental pollution and the production of environment friendly agricultural products through resources recycling.

• Korean Journal of Organic Agriculture
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• v.22 no.4
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• pp.731-742
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• 2014

In the current study, we investigated effects of a combination of earthworm casting, environment-friendly by-product fertilizer, and cultivation soil of Gymnocalycium mihanovichii in a heavy fertilizing culture on diameter, height, numbers of tubercles, and chemical properties of soil thereby elucidating optimal mixture ratio for securing production as well as providing nutrients throughout cultivation period. The Gymnocalycium mihanovichii var 'Ihong', one of grafted cactus for export (Rootstock: 9 cm, Scion: $1.5{\times}1.3cm$ grafted cactus) was cultured in plastic houses of Agricultural Technology Center located in Naegok-dong, Seocho-gu, Seoul from June, 2013 through December, 2013. For the control group, a mixture of sand and fertilizer (50:50) was used as this ratio is widely utilized in farmhouses. In contrast, a variety mixtures of sand and earthworm casting that was produced with food wastes was compared; the mixture ratios were 80:20, 60:40, 40:60, 20:80, and 0:100 and pH for these mixtures were found to be similar each other (ranging between 7.1 and 7.4) which is in an appropriate range (pH 6.5-7.5) for cultivation of G. mihanovichii. The organic content was increasing along with increasing contents of earthworm casting ratio while it was lower than the treatment practice group (32-43 mg/kg vs. 55 mg/kg). The content of exchangeable cation was also increasing as the ratio of earthworm casting was elevated; although levels of $K^+$, $Na^+$, and $Mg^{2+}$ were lower than the treatment practice group, the level of $Ca^{2+}$ was higher ($9.1cmol^+/kg$ and $11.5-33.7cmol^+/kg$ in the treatment practice group and the earthworm casting group, respectively). Three months after grafting, diameters of G. mihanovichii were compared with the control group; consequently, there was a significant difference noted in between the earthworm casting group and the control group (31.39 mm vs. 32.46-37.59 mm). After 5 months, growth characteristics of G. mihanovichii were evaluated. Similarly, the diameter of G. mihanovichii was significantly increasing in the group with higher ratio of earthworm casting treatment (32.63 mm vs. 32.49-37.59 mm). The height of tubercles was 2.63 mm in the control group while it was significantly elevating along with the ratio of earthworm casting mixture. The more numbers of tubercles, the more incomes for farm-houses; as results, higher mixture ration of earthworm casting resulted more numbers of tubercles compared to the control group (2.7 vs. 3.2-8.3 ea). In particular, in the earthworm casting groups with 80% and 100% ratios, the numbers of tubercles were 6.2 and 8.3 ea, respectively, which is 2.5 times more than those of the control group. These results indicate that earthworm casting treatment may be utilized in G. mihanovichii farming houses for short term production of tubercles. In the group with 40% and 60% of earthworm casting mixture, the numbers of tubercles were found to be 4.5 and 4.8 ea, respectively which is higher than the control group as well; in these groups, there were no issues with soil drainage as well as moss formation. Given the analysis results of growth characteristics of G. mihanovichii, it was concluded that 40% and 60% of earthworm casting mixture might be the optimal ratios.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.5
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• pp.822-828
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• 2012

Organic fruit production has increased due to consumer's interest and government's political support for environmentally-friendly agriculture. The aim of this study was to investigate the effects of cover plants on soil microbial community and establish the fruit cultivation method by organic farming techniques. Cover plants used as an organic nutrient source in an apple orchard were rye and barley, the Gramineae and red clover and hairy vetch, the Leguminosae. In the effects of cover plants on the soil chemical characteristics, the soil pH values were higher than that of conventional organic pear orchard. The content of P showed no significant difference between control and cover plant plots. Organic matter level was similar in control and Gramineae cover plant plots, while organic matter content in cover plants belong to Leguminosae was lower than that of control plot. K content was lower in the plots treated with rye and red clover than control plot, while K content in hairy vetch treated plot was higher than control plot. Ca content was lower in control plot than in cover plant treated plots. Concentrations of Mg in the plots treated with barley and hairy vetch was lower than control plot. In August rye and red clover covered soil showed higher bacterial community density than that of control soil and barley treated soil showed highest Actinomycetes community density among treatments. Barley and hairy vetch soils showed higher level of fungi community density than that of control soil in August. In pyrosequencing analysis barley treated soil showed highest distribution ratio of Actinomycetes among treatment. Our findings might be used as basic data for choosing cover plant with effective organic matter decomposition and nutrition supply capacity.

• Korean Journal of Soil Science and Fertilizer
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• v.42 no.spc
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• pp.57-61
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• 2009

To clarify the impact of the rice-duck farming system on the regional environment and the surrounding, a case study was carried out at Hongdong Reservoir valley of Hongdong-myeon and Janggok-myeon, Hongseong-gun, Chungcheongnam-do where the density of livestock grazing is the highest and rice cultivation with the rice-duck farming system is extensively practiced. The soil characteristics and water qualities at paddy fields were compared between two rice cultivation methods of rice-duck farming system and conventional farming system. The organic matters and available phosphate contents in soil of paddy fields where the rice-duck farming system was practiced were higher than those of paddy fields where conventional farming system was practiced. However, the available phosphate content was lower than the optimum for rice cultivation and the mean concentration of paddy soil in Korea. The surface water quality of the paddy field with the rice-duck farming system was practiced had higher EC (137 %), $COD_{Cr}$ (220 %), T-N (172 %), and T-P (226 %) contents than that with the conventional farming system was practiced. Especially, $COD_{Cr}$ and T-P were more than 2 times higher, which tells that the possibility of water pollution by drainage water of paddy field is higher in the paddy fields with the rice-duck farming system practiced than in those with the conventional farming practiced. The higher contents of T-P and $COD_{Cr}$ in surface water at the paddy field of rice-duck farming system practiced were directly caused by soil particles in the muddy water. Consequently, it is necessary to thoroughly manage the irrigation and drainage system of rice-duck farming system practiced to prevent outflow of surface water from paddy and pollution of surrounding water system.

• Journal of dental hygiene science
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• v.13 no.1
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• pp.97-104
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• 2013

This study investigated the safety management behavior of dental professionals to minimize exposure to harmful elements of amalgam and resin. As for the use of amalgam and resin, 85.8% of them used amalgam. 100% of used composite resin 100%. 97.8% used acryl resin, and 95.7% used tray resin. 95.2% and 36.5% of them were aware of the harm of amalgam and resin respectively. When using resin, their safety management behavior score was 1.99 on average, and the lowest score was 2.50 on average for 'ventilate the indoor air when handling resin'. Their average score of the safety management behavior was 1.83 when using amalgam. The lowest score was 2.89 on average for 'use the rubber dam for patients when handling amalgam'. As a result of the safety management behavior based on general characteristics, all characteristics were significant with regard to amalgam, and my position at work and work experience were significant with regard to resin (p<0.05). The correlation between the safety management behavior and general characteristics was analyzed when dental amalgam and resin are used. Amalgam was statistically correlated with academic background (p<0.05) and position at work (p<0.05), whereas resin was statistically significantly correlated with age (p<0.05) and position at work (p<0.05). Accordingly, education about the harm of dental materials must be continuously provided for dental professionals when they handle dental materials so that safety management behavior will be conducted correctly, and active efforts to protect the health of dental professionals from harmful chemicals must be made.