• Korean Journal of Soil Science and Fertilizer
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• v.26 no.2
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• pp.132-137
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• 1993

This study was conducted to establish a safe cultivation technique of rice in the area irrigated with polluted water. The changes of water and grain quality were investigated in the two paddy soils which are located in the adjacent of Geumho river in 1991. The results obtained in this study are as follows : 1. The qualities of irrigation water were shown to be in the range of 6.7~7.4 in pH, 21.3~52.8ppm in COD. 3.2~5.3ppm in $NH_4-N$ and 1.6~6.0ppm in $PO_4$, respectively. Concentration of COD and $NH_4-N$ were over the standard levels. Therefore, the water pollution was mainly caused by organic waste matters. 2. Ranges of the Soil pH of Gyeongsan and Gyuam series were 5.6~6.0, 6.1~6.3 respectively. The contents of avaiable $P_2O_5$ and $SiO_2$ were high in the silicate treatment plots among other plots. 3. Degree of irrigation water pollution of Geumho river showed the highest peak in June. 4. Plant height, number of panicle and yield of rice grain were not decreased by the diminution of nitrogen fertilizer application. 5. The $Mg/(K{\times}N)$ ratio and Gel consistency of milled rice were increased in the nitrogen decreasing plot, but the alkali digestability value and protein content were decreased. Therefore, it was desirable to decrease the amount of nitrogen fertilizer application.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.5
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• pp.808-813
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• 2011

This study was conducted to reduce the dependability of farmers on chemical fertilizers for rice cultivation. Soil chemical and biological properties were monitored before experiment and at the time of harvesting. The results showed that EC, available $SiO_2$, and exchangeable $Ca^{2+}$ were decreased at the time of harvesting while pH, OM, and exchangeable $K^+$ and $Mg^{2+}$ were remain unchanged, compared with soil before experiment. Population of aerobic bacteria, Bacillus sp., and fungi were also increased at the time of harvesting in the paddy field, compared with before fertilization, in the treatment of 50% soil-testing fertilizer+ 50% compost. Concentrations of N, P, and K in rice leaves increased with the fertilizers application, maximum increase was recorded in 50% soil-testing fertilizer+ 50% compost. Non-significant difference was observed in the morphological parameters of rice among the treatments. The chlorophyll contents of rice leaf increased in a similar fashion up to 60 days, thereafter, sharp decrease was observed in all the treatments. Maximum yield (per 10a) was recorded in the field treated with 50% soil-testing fertilizer+ 50% compost followed by standard applied fertilizer, 70% soil-testing fertilizer+ 30% compost, soil-testing fertilizer and unfertilized plot. Amylose content showed non-significant difference within the treatments. Protein content increased with the use of fertilizers and best protein content was recorded in the treatment of 50% soil-testing fertilizer+ 50% compost. It was concluded that the amount of the chemical fertilizer used was directly proportional to the protein content of rice grain. However, the palatability of rice grown in unfertilized field was better than the treatments but minimum yield was obtained. Hence, the treatment of 50% soil-testing fertilizer+ 50% compost, was the best among the fertilizer combinations for rice cultivation as supported by the yield, protein and palatability index.

• Korean Journal of Soil Science and Fertilizer
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• v.41 no.2
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• pp.103-111
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• 2008

This study was carried out to investigate the optimal application rate and time of mixed expeller cake (MEC) for the replacement of chemical fertilizer. Dongjin-1, as cultivated rice was used at Fluvio-marine deposit in Honam plain paddy field. Soil chemical properties were improved by the application of MEC. Contents of total nitrogen and organic matter were higher in 70%, 100% plots of basal dressing than standard fertilizer application (SFA) plot. Cation exchangeable capacity was highly increased in 70% plot of basal dressing. Also, the content of organic matter in soil was increased with MEC application. Cation exchangeable capacity, total nitrogen and available phosphate were decreased according to late application time. The content of inorganic nitrogen in soil showed high tendency at more application rate of MEC, and nitrogen mineralization at harvest season have finished in 50%, 70% plots of basal dressing. The content of inorganic nitrogen in soil was increased according to late application time, however it was decreased in the late period of growth. Leaf color value became darker with increased application rate of MEC. Leaf color was dark green in MEC application plots at panicle formation stage, on the other hand, it was light green in 50%, 70% plots of basal dressing at heading stage. SPAD reading value of leaf-color was high during the whole growth stage in MEC application plots. More application rate of MEC showed higher tendency of fertilizer nitrogen absorption. Nitrogen use efficiency was the highest in 70% plot of basal dressing. Absorbed amount of fertilized nitrogen was increased in 10~15days before transplanting and nitrogen use efficiency was high according to the late application time. The ratio of perfect kernel and the content of protein on hulled rice showed high tendency at the less application rate of MEC. The ratio of head rice on milled rice showed high tendency at the less application rate of MEC. Rice yield increased 4% in 100% and 70% plots of basal dressing compare with SFA ($5.18Mg\;ha^{-1}$) plot respectively. Ear and culm length of rice were long according to the late application time, while the numbers of spikelet and ear were increased and the percentage of ripened grain was decreased. Rice yield was increased 2~5% in all MEC application plots compared to SFA plot and especially, increased 10~15days before transplanting in application plots. The optimal application rate and time of MEC on normal paddy field in plain were concluded that 70% basal dressing and 10~15days before transplanting

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.5
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• pp.643-648
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• 2005

Near infrared reflectance spectroscopy (NIRS) has become increasingly used as a rapid, accurate method of evaluating some chemical constituents in cereal grains and forages. If samples could be analyzed without drying and grinding, then sample preparation time and costs may be reduced. This study was conducted to develop robust NIRS equations to predict fermentation quality of corn (Zea mays) silage and to select acceptable sample preparation methods for prediction of fermentation products in corn silage by NIRS. Prior to analysis, samples (n = 112) were either oven-dried and ground (OD), frozen in liquid nitrogen and ground (LN) and intact fresh (IF). Samples were scanned from 400 to 2,500 nm with an NIRS 6,500 monochromator. The samples were divided into calibration and validation sets. The spectral data were regressed on a range of dry matter (DM), pH and short chain organic acids using modified multivariate partial least squares (MPLS) analysis that used first and second order derivatives. All chemical analyses were conducted with fresh samples. From these treatments, calibration equations were developed successfully for concentrations of all constituents except butyric acid. Prediction accuracy, represented by standard error of prediction (SEP) and $R^2_{v}$ (variance accounted for in validation set), was slightly better with the LN treatment ($R^2$ 0.75-0.90) than for OD ($R^2$ 0.43-0.81) or IF ($R^2$ 0.62-0.79) treatments. Fermentation characteristics could be successfully predicted by NIRS analysis either with dry or fresh silage. Although statistical results for the OD and IF treatments were the lower than those of LN treatment, intact fresh (IF) treatment may be acceptable when processing is costly or when possible component alterations are expected.

• The Korean Journal of Pesticide Science
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• v.19 no.3
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• pp.218-229
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• 2015

The proficiency testing for the residue laboratories of pesticide registration was conducted in order to improve the reliability and the ability for pesticide residue analysis. On November 2012 the testing was carried out using the soil collected and kept as the moistened state for five years, which was expected to very low residue levels of pesticides. The soil was fortified with azoxystrobin, imidacloprid and methabenzthiazuron in a manner similar to prepare soil samples for indoor soil degradation test, and then sub-samples were prepared for the distribution to participants. Some of them were randomly selected for confirm of homogeneity and to ensure the stability of samples at room temperature. Samples were consisted of two soils treated as different levels, one of which was used to the assessment and another used to confirm. In addition, provided three standard solutions, respectively concentration of 10 mg/L, and untreated soil. Forty eight institutions submitted results. The medians of results were used as the assigned values for pesticide residues. Fitness for purpose standard deviation of proficiency test was calculated by applying 20% RSD as the coefficient of variation allowed in the soil residue test. Z-score was applied for evaluation of individual pesticides, and the average of the absolute value of the Z-score for the overall assessment of pesticides. Laboratories evaluated the absolute value of the Z-score less than 2 to fit the case of azoxystrobin were 48, imidacloprid and methabenzthiazuron 46.

• Journal of Korea Water Resources Association
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• v.50 no.6
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• pp.373-386
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• 2017

This study simulated water quality item and flow rate of subbasin for Saemangeum watershed using Soil and Water Assessment Tool (SWAT) model and Environmental Fluid Dynamics Code (EFDC) model which simulate hydraulic and water quality in three-dimensions. The simulated values corresponded to observed value well. The result of simulation for floodgate operations at the M3 and M5 points, it exceeds water quality standard and at the M3 and D3 points, change of range for concentration is too wide, and upstream of Saemangeum reservoir is sensitive to inflow flow rate. Compared to the annual average concentration for observed station according to the discharge conditions, improvement of water quality for upstream was apparently compared to the downstream. Range of influence for change of water quality presented that maximum discharge condition, the influence range is 22 km in the direction of the Saemangeum downstream from the Mankyung bridge, and 15 km in the downstream direction of saemangeum in the Dongjin bridge. This study result demonstrated that floodgate operating at upstream has significant influence on water quality management of Saemangeum reservoir and it needs to be considered in plans of water quality management for Floodgate operation on Saemangeum reservoir.

• Journal of Soil and Groundwater Environment
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• v.12 no.3
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• pp.75-80
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• 2007

This study evaluated groundwater quality around an uncontrolled landfill in W sity, Korea, which was monitored for about two years (2005-2006). Parameters of concern include redox-sensitive indicators such as pH, DO, EC, ORP, DOC (dissolved organic carbon), NH3, NO3 and SO4. About 10 years have elapsed after closing dumping of municipal wastes in the landfill. Leachates showed widely varying concentrations in COD(136${\sim}$263 mg/L), T-N(121${\sim}$186 mg/L), and NH3-N(14${\sim}$369 mg/L). Groundwater at the immediate downgradient of the landfill showed weakly acidic pH condition but very high levels of EC (3,000-4,000 ${\mu}S/cm$), which indicated that the groundwater was largely affected by the landfill leachate. Cl, a conservative ion, showed over 200 mg/L at the landfill border, but a gradually decreasing level with distance from the landfill, representing dispersion and dilution (natural attenuation) due to mixing with surrounding groundwater and replenished rainwater. Redox potential showed negative value at the landfill border but it increased up to 350 mV at downgradient wells, which indicated conversion of redox condition from reducing oxic ones. Ammonia, was largely enriched at most of the monitoring wells and its level greatly exceeded drinking water standard. In summary, all the parameters evidenced occurrence of natural attenuation with distance and with time but further monitoring is still required.

• Korean Journal of Ecology and Environment
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• v.35 no.1 s.97
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• pp.45-51
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• 2002

This study was investigated to tile influences of clearcutting of timber harvesting on stream water quality at a natural deciduous forest catchment within the Seoul National University Research Forests in Mt. Baegun, Chunnam province during the periods of 1993 to 2001. Soil chemical ingredients and stream water qualities were monitored at 13 ha clearcutting site, non-treatment site and included in these catchment nearby. After the harvesting first and End years, the levels of total- N,　and exchangeable ions ($K^+,\;Na^+,\;Ca^{2+},\;Mg^{2+}$) were decreased the values of before　harvesting, and after the harvesting 111th years and eighth years, respectively. But the chemical characteristics of soil were not changed at all. pH of water in the harvesting area was 6.5 in stream water. Among the nutrient, Cd, Pb, Cu, and phosphate were not found, and the level of BOD reached at the level of the domestic use for drinking. Turbidity, odor, taste, $NH_4\;^+-N,\;NO_3\;^--N$, standard plate count, and coliform were also low enough to be used as the domestic use for drinking in the near villagers. Total amount of cation, total amount of anion and total amount of ion in clearcutting site, non- treatment site and included in these catchment nearby were higher than clearcutting site and non- treatment site. But, there was no great difference.

• Journal of Practical Agriculture & Fisheries Research
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• v.5 no.1
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• pp.28-35
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• 2003

This study was conducted to investigate the nutrition status, growth and fruit quality of 'Campbell Early' grapes in Hwaseong area. Organic matter content of 3 vineyard soils was significantly lower than standard value. P₂O₅ and K contents of Y vineyard and P₂O₅ of C vineyard were very high. But there were no significant differences in contents of Ca, Mg and CEC. Compared to the standard value. T-N, Ca and Mg contents of petiole were adequate. P₂O₅ contents of Y and C vineyard and K contents of Y vineyard were significantly higher than standard value. Berry firmness, color and bloom occurrence on fruit skin showed no differences among 3 vineyard. Soluble solids content poorly, yield per tree and goods fruit of C vineyard decreased significantly compared to the fruit in Y and H vineyards. Russetted fruit of Y vineyard, colored fruit of H vineyard, and unfertilized fruit, cracked fruit, and bitter rot were observed frequently.

• Journal of Soil and Groundwater Environment
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• v.17 no.6
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• pp.102-111
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• 2012

Fine suspended solids generated effluence from treatment process of mine drainage could destroy environment as the aesthetic landscapes, and depreciate water quality. Therefore, the purpose of this research is focused on process development applied the actual field for controlling fine suspended solids and heavy metals, and so lab-scale test was performed for inducement of basic data. The mine drainage used in this research was sampled in H mine located Jeongseon-gun, Gangwon-do. Concentration of suspended solid, arsenic, iron and manganese was exceeded the standard of contaminant limitation for the clean water, and particle size of suspended solid was less than 10 m as fine particle. Although hydraulic retention time of mine drainage for effective settling was required more than 6 hours, hydraulic retention time would be increased in winter season when the settling efficiency could be reduced because of viscosity decreasing. Moreover, installed inclination plate helped to increase settling efficiency of suspended solid about 48 %. Filtering media that was the most effective removal of suspended solids and heavy metal was decided granular activated carbon of 1~2 mm was the optimal size.