• Journal of Sericultural and Entomological Science
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• v.28 no.2
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• pp.1-8
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• 1986

This study was conducted to bring light on inducing factors for non-sprouting occured in the mulberry field of Kyungpook Province in 1983. The results are as follws ; 1. In spring, winter buds were suddenly died during germination, necrosis appeared in pholem and cortex of non-sprouting stem and measles at the bottom of non-sprouting stem. 2. The depth of available of soil was more shallow in the non-sproutiong field than in healthy field. 3. There was no signifioant difference between the healthy field and non-sprouting field in siol PH, the content of organic matter, available phosphorous and exchangeble cations. 4. Available boron content in soil was significantly more in healthy field than in non-sprouting field. 5. Boron content in leaf and bark was significantly lower in the non-sproutiong tree than in the healthy tree. 6. The non-sprouting fields were completely controlled by the application of 6kg/10a borax. 7. Cold tolerance of the mulberry tree was higher in the mulberry tree with boron than in the mulberry tree without boron. 8. Mulberry tree in Kyungpook Province in 1983 may absorb water earlier compared with the average year because of high temperature at the end of March, 1983 and they had been damaged by frost injuary due to the lowest temperature (-6.4$^{\circ}C$) on the grass at the beginning of April 1983. As the above results, non-sprouting bud in the mulberry fields of Kyungpook Province in 1983 had been occured by low temperature and boron deficiency and boron deficiency of mulberry trees accelerared the frost injury.

• KCID journal
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• v.19 no.1
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• pp.40-49
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• 2012

This study was performed to monitor the runoff of sandy soils on alpine uplands between March 2008 and December 2009, and assess non-point source pollution load. The fields were used to cultivete poteto in 2008 and radish in 2009. The fertilizers used in 200S, compared to those used in 2009, contained 2.1 times of nitrogen, 1.9 times of phosphorous, and 2.3 times of potassium. In 2008, the annual pollution load indiceted SS 2,908.47kg/ha/yr, COD 67.95kg/ha/yr, BOD 50.72kg/ha/yr, TN l3.29kg/ha/yr, and TP 9.97kg/ha/yr. In 2009, the annual pollution load indiceted SS 3,908.34kg/ha/yr, COD 225.04kg/ha/yr, BOD 156.96kg/ha/yr, TN 18.88kg/ha/yr, and TP 36.41kg/ha/yr. The amount of fertilizers used was about twice greeter in 2008, but the amounts of TN in pollution load per unit of rainfall were similar by 0.031kg/ha/mm to 0.029kg/ha/mm, whereas the amounts of COD (0.16kg/ha/mm to 0.35kg/ha/mm), BOD (0.12kg/ha/mm to 0.24kg/ha/mm), and TP (0.023kg/ha/mm to 0.057kg/ha/mm) doubled in 2009. We can infer thet the surface covering by the growth of crop mainly affected the transport of T-N through the subsurface flow to reduce non-point source pollution.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.1
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• pp.23-31
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• 2012

Measures against non-point sources pollution in Saemangeum watershed should be established to control water quality of Saemangeum lake, because non-point sources pollution discharge portions of BOD (Biological Oxygen Demand) and TP (Total Phosphorous) in the watershed were 68.4 and 61.4%, respectively. In this study, target regions for the non-point sources pollution control were selected to apply BMP (Best Management Practices) for the agricultural area of Saemanguem watershed in terms of TP that caused eutrophication at the lake. Target regions were selected by the NPSI (Non-point source index) that was calculated by the total 12 indexes at the steps of non-point source production, emission and outflow. Weights of the indexes were determined by the watershed management experts oriented AHP (Analytic Hierarchy Process) analysis. The target region was selected at the unit of Korean basic administrative district 'Dong/Li'. At the results of NPSI calculations through the GIS (Geographical Information System) tools, two sets of 5 regions were selected in the Man-kyung River and Dong-gin River. The main reason for the selected target regions was livestock activity in the district. The results of this study can be useful for implementing the reduction projects of agricultural non-point sources pollution to control water quality in Saemangeum lake.

• Journal of The Korean Society of Agricultural Engineers
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• v.52 no.5
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• pp.47-52
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• 2010

The purpose of this study is to investigate characteristics of total phosphorus (TP) and phosphate phosphorous ($PO_4$-P) concentrations in ponded water and redox potential (Eh) in paddy soil during the growing season. The TP and $PO_4$-P concentrations showed twice peak values after basal dressing and tillering fertilization. The ratio of $PO_4$-P to TP showed low values (0.07~0.18), indicating that most of phosphorus is particlulate. The $PO_4$-P concentrations significantly decreased with dissolved oxygen (DO) concentrations. The Eh showed high values (179~636 mV) under non-ponded aerobic condition, but low values (74~112 mV) under ponded anaerobic condition The TP and $PO_4$-P concentrations in ponded water increased shortly after tillering fertilization even if phosphorus was not applied. This may be due to the release of dissolved phosphorus from the bottom sediment and its associated algal and water flea blooms under anaerobic condition. Therefore, proper water management should be needed shortly after tillering fertilization.

• Asian-Australasian Journal of Animal Sciences
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• v.9 no.2
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• pp.123-126
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• 1996

Sixteen Harnai males were used to evaluate the influence of varying levels of fourwing saltbush hay on feed and water intakes as well as the blood serum mineral status in a completely randomized design. The animals were grouped randomly into four, with four animals in each. The four groups were randomly allotted low, medium, high and very high levels of saltbush hay supplementation in addition to wheat straw. The animals were given fresh water at free of choice. Weekly body weight was recorded for each individual animal. Blood serum was collected for mineral contents. The experiment lasted for eight weeks. The inclusion of saltbush leaves in the diet showed a non-significant effect on the total dry matter intake. There has been a significant increase in the water intake when very high levels of saltbush were included in the ration. Lower levels showed no effect on the water intake. The animals maintained their body weight from week 1 to week 8. No treatment by weeks interactions on the potassium and sodium levels were detected. However higher levels of saltbush increased significantly the potassium and sodium contents in the serum. Calcium contents were significantly(p<0.01) lowered with the inclusion of saltbush leaves in the diet. Whereas Phosphorous contents showed an increasing(p<0.05) trend with the higher levels of saltbush. No clinical or sub-clinical toxicological symptoms were observed in the sheep with the higher mineral contents.

• Journal of environmental and Sanitary engineering
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• v.2 no.2 s.2
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• pp.69-78
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• 1987

Due to the increase of population and development of industry, the demand of available water resources increased . Many reservoirs have been constructed in large scales to meet this urgent need , resulting in the increased amount of water resources. After the constructions, however, serious pollution-especially eutrophication-in some reservoirs become a socialaffair. Therefore, water quality control in these resources should be considered more intensively than any other environmental preservation policies. It also seems to be imminent to prepare the precautionary steps. Most water pollution in Korea-73 percent - can be traced to domestic sewage. It may rome as a surprise to Some, Industry is responsible for just 27 percent of ]Korea's water pollution. What he calls 'non-point' Sources, which may include agricultural Chemicals, Create only negligible amount of water pollution. Up to $15\%$ of domestic sewage is treated in Korea, which is quite low when compared with the waste processing in developed countries. So it is the most urgent matter to control the pollution sources. One of the precautionary plans, more urban domestic sewage treatment plants must be installed and operated efficiently. It is known that nutrients such as nitrogen and phosphorous are the major factors the process of eutrophication, which can be removed majorly by the tertiary or advanced treatment process.

• Journal of The Korean Society of Agricultural Engineers
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• v.49 no.1
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• pp.89-97
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• 2007

Simple regression models for pollutants load estimation of paddy developed by the Ministry of Environment in 1995 were tested with the data (T-N, T-P, $COD_{Mn}$, and SS) collected from Yeongsan and Seomjin river watersheds, and improvement measures were suggested. Overall, the simulated values showed a great difference from the measured values except for T-P according to the statistical analyses (RMSE, root mean square error; RMAE, root mean absolute error; RB, relative bias; EI, efficiency index). Such difference was assumed due to the fact that the models use only hydrologic factors (quantity factor) associated with precipitation and run-off as input parameters, but do not consider other factors which are likely to affect pollutant concentration (quality factor) including days after fertilization. In addition, in terms of accessibility of the models, some parameters in the models such as run-off depth and run-off amount which can not be obtained from the weather database but should be collected by on-site measurements need to be replaced with other variables.

• Environmental Engineering Research
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• v.17 no.2
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• pp.59-63
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• 2012

This paper proposes a modified Ludzack-Ettinger (MLE) type membrane bioreactor (MBR) as a method of treatment for wastewater from food waste disposer. Micro-membrane filtration allows for an extremely low concentration of suspended solids in the effluent. The effluent of the reactor in question is characterized by a relatively high level of non-biodegradable organics, containing a substantial amount of soluble microbial products and biomass. Results obtained in this paper by measurement of membrane fouling are consistent with biomass concentration in the reactor, as opposed to chemical oxygen demand (COD). The MLE process is shown to be effective for the treatment of wastewater with a high COD/N ratio of 20, resulting in are markedly high total nitrogen removal efficiency. Denitrification could be improved at a higher internal recycle ratio. Despite the low concentration of influent phosphorus, the phosphorus concentration of the outflow is seen to be relatively high. This is because outflow phosphorous concentration is related to COD consumption, and the process operates at along solids retention time.

• Journal of The Korean Society of Agricultural Engineers
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• v.54 no.3
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• pp.91-101
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• 2012

This study is to assess the runoff characteristics of nonpoint source pollution loads for Jecheon and Jangpyeong stream watersheds located in the upstream of Chungju lake. The SWAT (Soil and Water Assessment Tool), a physically based distributed hydrological model was calibrated and verified using 5 years (2006 to 2010) streamflow and water quality data. The Nash-Sutcliffe model efficiency for streamflow was 0.60~0.92 and the determination coefficients for sediment, Total Nitrogen (T-N), and Total Phosphorous (T-P) were 0.53~0.71, 0.51~0.91 and 0.38~0.85 respectively. The results showed that the Sediment, T-N, and T-P of Jangpyeong stream were 40.0~60.9 %, 34.8~64.1 % and 76.5~83.9 % higher than Jecheon stream watershed during wet days. The results evaluated high NPS loads at Jangpyeong stream because the percentage of urban and upland crop cultivation area Jangpyeong stream watershed was higher than Jecheon stream watershed.

• Korean Journal of Soil Science and Fertilizer
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• v.42 no.6
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• pp.409-414
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• 2009

In 1970's Black locust(Robinia pseudoacacia) had been widely planted Korea as an important forest greening species for erosion control afforestation. Since 2000, however, the tree's leaf-yellowing symptom has often been observed at a limited region and then spreaded out over the country in 2006. This study was conducted to study soil physiochemical properties of black locust stands with and without the leaf-yellowing symptom in Osan, Gyeonggi province. Most of soils in sampling sites were mostly slightly eroded, dry, and moderately dry. Available soil depth(16cm) and total soil depth(26cm) in leaf-yellowing (LY) site were significantly lower than in non leaf-yellowing (Non-LY) site's soil depths which were 30cm and 56cm, respectively. And solid phase proportion and bulk density in soils were lower in LY site than in non-LY site soils, while soil liquid phase proportion was also low. It could reflect that LY site soils might have a lower air and moisture movement in the rhizosphere of black locust stand compared with non-LY site soils. Soil acidity in both sites was very strong acid, soil pH (4.42) of LY site was slightly lower than non-LY site's (pH 4.54). Content of available phosphorous, exchangeable $Ca^{2+}$ and $Mg^{2+}$ and percent base saturation were less than LY site. These results indicated that soil physiochemical condition in LY site, more deteriorated than non-LY site, should adversely affect the retention and supply capacity of soil nutrients and moisture. Therefore the black locust may be more sensitive to other environmental stresses.