• The Journal of Korean Medicine
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• v.16 no.2 s.30
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• pp.17-35
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• 1995

Clinical observation was made on 161 cases of CVA that were confirmed through brain CT, MRI scan and clinical observation. They were hospitalized in the oriental medical hospital of Kyung-Won University from January to December in 1994. 1. The CVA cases were classified into the following kinds: cerebral infarction, cerebral hemorrhage, subarachnoid hemorrhage(SAH), transient ischemic attack, hypertensive encephalopathy, and the greatest in number among them were the cases of cerebral infarction. 2. The frequency of strokes was much the same between male and female cases and most cases were over 50 of age. 3. In the case of cerebral infarction the place of the most frequent occurrences was in the MCA territory, and as for cerebral hemorrhage, in the basal ganglia area. 4. The most ordinary preceding disease was hypertension. The next was diabetes mellitus. 5. Generally it is thought that CVA occurs frequently in winter. But on the contrary this study of observation confirmed that it occurs mostly in summer. 6. The predisposing factors of cerebral infarction were usually initiated during the time of resting and sleeping and those of cerebral hemorrhage chiefly during the time of exercising. 7. As concerns the course of hospitalization, most patients passed through western medical hospitals or oriental medical hospitals. 8. For the patients the condition of whose consciousness was bad at the time of admission, the prognosis in most cases was bad. 9. The common symptoms were motor disability and verbal disturbance. 10. With regard to cerebral infarction, the average time to start physical theraphy was 11.4 days and with cerebral hemorrhage 22.7 days after stroke. 11. The duration of hospitalization was in most cases more than one month. 12. The main complication was urinary tract infection. The next was pneumonia. 13. At the time of admission to hospital, the blood pressure in most cases was high, but it well controlled at the time of discharge. 14. Most cases were given simultaneous treatment in both ways of western and oriental medicine.

• Korean Journal of Environmental Agriculture
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• v.9 no.2
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• pp.133-141
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• 1990

For the purpose of evaluating nutrient loadings into rivers and lakes from agricultural land, especially from paddy fields and also nutrient degradation in drainage channels, the Total Kjeldahl Nitrogen(TKN) and the Total Phosphorus(TP) were investigated in 29.5 ha. paddy fields in Hwa-Sung, Kyong-Ki, Korea, during the period from May 8, 1989 to Sep. 27, 1989. The results of the study can be su㎜arized as follows : 1. Annual inputs into paddy fields were 180 N-kg/ha 46 P-kg/ha. by fertilization, and 15.0 TKN-kg/ha. 10.0 TP-kg/ha. by irrigation, 8.0 TKN-kg/ha. 0.34 TP-kg/ha. by rainfall respectively. The amount of nutrient involved in surface runoff from paddies was 39.0 TKN-kg/ha. 9.2 TP-kg/ha. and in seepage 7.5 TKN-kg/ha. 2.1 TP-kg/ha. respectively 2. In WS1 stream(reach length equals 950m), nutrients decreased 0.31 TKN-mg/L/km, 0.01 TP-mg/L/km and in WS2 stream (reach length equals 750m) which are more meandering and undulating than WS1, the nutrients decreased 0.84 TKN-mg/L/km, 0.11 TP-mg/L/km. From these results, it was concluded that low stream velocity due to meandering and undulation promotes more degradation of nutrient concentrations. 3. For the purpose of decreasing nutrient loads from paddy fields, the amount of fertilizer used needs to be controlled, irrigation weirs need to be constructed in the drainage channels to delay the transportation of nutrients by decelerating the stream velocity and plants such as plantain-lily need to be cultivated in the channel to consume nutrients and therefore enlarge chances of self-purification.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.25 no.2
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• pp.6-14
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• 1980

One of the physiological disease, sudden wiliting of Yushin variety suggested that low sunlight, excessive nitrogen application, and highly reduced soil condions either singly or combined, might be possible causes of the disorder. Some visual symptom of sudden wilting are discoloration of leaves, development of nodal roots above the soil surface, total root rot, and lodging. Those observations led to the hypothesis that suffocation of root tissues was a direct cause of the wilting. The oxygen transport characteristics of Yushin, IR262 and Tongil were examined by two methods. First, Soil-cultured plants of the three varieties were subjected to paraffin treatment to decrease the oxygen supply from the air to root tissues through the soil-water system, liquid paraffin was applied to the water surface in the pots at panicle formation stage. In this experiment, sudden wilting was observed of Yushin and IR262 at about a week after the treatment, but Tongil remained green and healthy. Wilting-resistant variety Tongil had higher oxygen release, whereas the susceptible Yushin and IR262 had lower oxygen release. Second, the number and size of the air spaces in each internode were investigated in the 5th internode from the top, all three varieties have a similar number of air spaces, although the air spaces of Thongil were larger. In the 4th internode, Tongil had plenty air spaces, Yushin and one of the Yushin's parents IR262 had scanty or none. The observations indicated that the ability of Yushin and IR262 for oxygen transport is very limited compared with that of Tongil. The limited oxygen supply due to poor development of air space in internode of rice plants may cause suffocation of root tissues, weaken metabolic activity of the tissues, and induce root rot, subsequently inducing sudden wilting and lodging under unfavorable weather, soil and cultural conditions.

• Korean Journal of Soil Science and Fertilizer
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• v.33 no.5
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• pp.318-324
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• 2000

Field experiment was conducted on a sandy clay loam paddy field in the Experimental Farm of the Kangwon National University for four years from 1995 to 1998 to evaluate the effect of different nitrogen fertilizers on soil property and rice yield. The size of each experimental plot was 75 m2. Basal application of fertilizer to the paddy field was on late April, and rice (cv. Odae) was sown with drill seeding on early May. Irrigation was done at 3 leaf stages after rice seeding. Electrical conductivity in soils treated with phosphate- and resin coated slow release fertilizers were relatively greater than those of the other fertilizer application. Available $P_2O_5$ concentration in soils after rice harvest increased significantly compared that in soil before field trial. Rice yield in transplanting culture were $6.516kg\;ha^{-1}$. The rice yield in the direct seeded paddy was 81.9 percents of the yield in the transplanted paddy. The rice yield in phosphate coated slow release fertilizer was the highest among various fertilizer trials in directly seeded dry paddy, while rice yield was the lowest in the organic fertilizer plus urea application. Rice yield between organic fertilizer plus urea and organic fertilizer application were not significantly different. The green manuring effect of rye in the direct seeded rice paddy in Chuncheon was low due to low temperature and short growth period.

• Korean Journal of Weed Science
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• v.5 no.1
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• pp.63-72
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• 1985

To establish the method of integrated weed management in rice nurserybed, phytotoxic factors of herbicide and antidote efficacy were evaluated at the Yeongnam Crop Experiment Station in 1982 and 1984. Seven hundred eighty four research items were carried out as weed control research since 1961. While 65% of these were belonged to rice research, only 6% was attributed to nurserybed among rice research. More herbicidal phytotoxicity exhibited when seedbed was pressed just after seeding than sand covered or uncovered seedbed and also this phytotoxic symptom enhanced by using intact seed compared to pregerminated seed. Rinsing practice of seedbed reduced the phytotoxic effect of butachlor and this effect was more pronounced with the number of rinsing operation increase and at the pressed plot. However, herbicidal efficacy was not significantly decreased by rinsing operation. Growth of rice seedling hardly affected where the herbicide was absorbed through root only compared to absorption from both of root and shoot for pyrazolate, butachlor and thiobencarb. Herbicide antidote `CGA 123'407' completely protected from the phytotoxic effect of pretilachlor without arising any adversal effect in weed control. However, without antidote, pretilachlor showed the most severe phytotoxic symptom among used herbicides.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.6
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• pp.1016-1022
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• 2011

Application of silicate fertilizers is typically practiced with several year's interval to amend soil quality and improve rice productivity at the paddy field in Korea. Most of silicate fertilizers applied in Korea is slag-originated silicate fertilizer. Some water soluble silicate fertilizers are manufactured and commercially available. The objective of this study was to assess changes of soil chemical properties in paddy field by applying slag-originated silicate fertilizer and water soluble silicate fertilizer. Field experiment was conducted on a silt loam paddy soil, where four levels of each silicate fertilizer were applied in soil at the rate of 0, 1, 2, 4 times of the recommended levels. Application of slag-originated silicate fertilizer increased soil pH, while no significant pH increase occurred with the treatment of water soluble silicate fertilizers. Soil pH increased 0.4~0.5 with the 1 time of recommended level of slag-originated silicate fertilizer. Available $SiO_2$ contents also significantly increased with the treatment of slag-originated silicate fertilizer at 15 and 35 days after treatment, while decreased after 60 days after treatment possibly due to rice uptake. Exchangeable Ca, Mg and available phosphate contents in soil increased with application of slag-originated silicate fertilizer, while a little increases for them were shown with the application of soluble silicate fertilizer. $SiO_2$/N ratios in rice straw for 1 time of recommended level of slag-originated silicate fertilizer was 11.5, while that of control was 8.4, which was much lower value. Throughout this study, soil application of slag-originated silicate fertilizer enhanced soil chemical properties, while water soluble silicate fertilizer application in soil needs further study resulting in a little effects on soil property.

• Journal of the Korea Organic Resources Recycling Association
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• v.19 no.4
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• pp.97-105
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• 2011

A wide diversity of liquid fertilizers and composts produced from the livestock manure in Korea is commonly applied to agricultural lands as an alternative of chemical fertilizers. However, their effects on the crop production and environmental impacts are still vague. The current study was investigated the property changes of paddy soils in sandy loam and silty loam treated with 1) control (no treatment), 2) chemicals, 3) storage liquid fertilizer and 4) SCB liquid fertilizer located in Gyeong-gi province, Korea. The chemical properties of soils in sandy loam and silty loam before the treatment were similar with the ones in the average paddy fields in Korea. Contrary to this, the amount of available phosphorus in sandy loam was higher than the one in the average paddy fields. The number of living organisms in sandy loam and silty loam treated with storage liquid fertilizer and SCB liquid fertilizer were higher than the ones in sandy loam and silty loam with no-treatment and chemicals. Significant difference (P<0.05) among the treatments and no-treatment was observed in sandy loam rather than in silty loam. The amounts of heavy metals were the highest in both sandy loam and silty loam treated with storage liquid fertilizer and SCB liquid fertilizer. The comparison of heavy metals showed that the ones in silty loam were little bit higher than sandy loam. The leaf lengths and dry weights of rices were increased over time, however, no significant difference was observed among each treament. In addition, the rice yield in sandy loam treated with SCB liquid fertilizer was higher than the ones in sandy loam. The highest rice yield was obtained from sandy loam treated with chemicals, but there was no significant difference between storage liquid fertilizer and SCB liquid fertilizer. While the rate of nutrient absorption by rices was the highest in sandy loam and silty loam treated with chemicals, there was no significant difference in sandy loam and silty loam treated with livestock liquid manure.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.67 no.1
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• pp.17-26
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• 2022

Rice is one of the three major grains globally, and has been used as a staple food in Asian countries for a long time. In recent years, with the increase in the use of processed rice, the development and distribution of rice flour varieties have become a research focus. However, rice flour varieties are susceptible to pre-harvest sprouting (PHS). In this study, the optimal transplanting date for rice flour varieties for maximum yield production with PHS avoidance was examined. Four rice flour varieties with different maturity types (early maturing type, Garumi2 and medium-late maturing type, Seolgaeng, Hangaru, and Singil) were selected. The field experiment was conducted in Chuncheon (Central Plain area) and Cheorwon (Northern Plain area), Gangwon Province, Republic of Korea, from 2017 to 2019. The transplanting dates used were May 10, May 20, May 30, June 10, and June 20 in Chuncheon and April 30, May 10, May 20, May 30, and June 10 in Cheorwon. In Chuncheon, late transplantation decreased PHS in Garumi2. In Cheorwon, PHS in Garumi2 decreased with transplantation dates after May 20. The PHS decreased in Seolgaeng, Hangaru, and Singil with late transplantation in Chuncheon and Cheorwon. The optimal transplanting date for maximum yield production while avoiding PHS for Garumi2 was estimated to be June 10 in Chuncheon and May 25 in Cheorwon; for Seolgaeng, the optimal transplanting dates were May 20 in Chuncheon and May 15 in Cheorwon; for Hangaru, it was estimated to be May 30 in Chuncheon and May 15 in Cheorwon; and for Singil, the optimal dates were May 25 in Chuncheon and May 15 in Cheorwon.

• Magazine of the Korean Society of Agricultural Engineers
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• v.15 no.3
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• pp.3059-3088
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• 1973

The Object of research was laid on the dry paddy field which had a low level of underground water, rather than on a paddy field with a high level of underground water. In the treatment of the clay paddy field before transplanting we employed 3 kinds of methods; deep plowing, development of cracks by drying the surface of the field under which pipe drain was built. This study was to find which one, among these three methods, is the most effective to let roots extend to deep zone and increase the yield of rice and at the same time, for trafficability of large scale machinery which will be introduced to the harvest, in the light of the earth bearing capacity in relation with underground drainage. In the treatments of plots, 1) the kyong plot was plowed 39 days before transplanting and dried, 2) the kyun plot was plowed again 2days before transplanting after plowing 39 days before transplanting, leveling field surface in the saturation with water and developing the cracks by drying, 3) the kyunam plot was plowed again 2 days before transplanting after setting the drainage pipe and at the same time plowing 39 days before transplanting, leveling field surface in the saturation with water and developing the cracks by drying. Also each plot above had three different levels of soil depth, respectively; that is 15cm, 25cm, 35cm. The kyong plot with 15cm-depth was he control. The results obtained were as follows; 1. The kyunam plot showed a remarkably lager amount of water consumption by better underground drainage than the kyong and the kyun plot, and the kyong plot indicated a greater amount of water consumption than the kyun plot. Therefore the amount of available rainfall was decreased in the order of kyunam>kyong>kyun. The net duty of water decreased in the order of kyunam>kyong>kyun and its showed about 105cm in depth at the kyunam plot, about 70cm in depth at the kyong plot and about 45cm in depth at kyun plot, regardless of soil depth. 2. According to the tendency that the weight of the total root was effected by the maximum depth of the crack, it seemed that the root development was more affected by the depth of the crack than by only the crack itself. The weight of the total roots tended to increase as the depth of the crack got deeper and deeper, and the weight of the total roots was increased in the order of kyun<kyunam<kyong. 3. In the growing of the plant height, the difference did not appear at the beginning of growing(peak period of tillering) of any plot, But for the mid period of growing(ending period of tillering) to the period of young panicle formation, the deeper the depth of plot is, the more the growing goes down. On the contrary at the late period of growing, growth was more vigorous in the plot with deep depth than in the plot with shallow depth. Since the midperiod of growing, in the light of experimental treatment, the kyun plot was not better in growing than the other two plots and no remarkable defference was shown between the kyunam and the kyong plot, but the kyunam plot had the tendency of superiority in growing plant height. 4. As the depth of plot went deeper, the decreasing tendency was shown in the number of tillers through a whole period of growingi. When the above results were observed concering each plot of experimental treatment, the kyun plot was always smaller in the number of tiilers than the kyunam and the kvong plot, and the kyong plot was slightly larger than the kyunam plot in the number of tillers. 5. When each plot of the different experimental treatments was compared with the control plot(15-kyong), yield(weight of grains) was increased by 17% for the 35-kyong plot, by 10% for the 35-kyunam and yields for the other plots were less or nomore than the control plot. On the whole, as the depth of plot went deeper, yields for plots was increased in the order of kyong>kyunam>kyun. 1% of significance between the levels of depths and 5% of significance between the treatments were shown. 6. The depth of consumptive water which was more effective on the weight of grains is that of the last half period. When the depth of consumptive water was increased at the range of less than 2.7cm/day in the 15cm plot, 3.0cm/day in the 25cm plot and 3.3cm/day in the 35cm plot, the weight of grains was increased, and at the same time the weight of grains was increased as the depth of plot went deeper. The deeper plots was of advantage to the productivity at the same depth of consumptive water. 7. The increase in the weight of grains in propertion to the weighte of root showed a tendency to increase depending on the depth of plot at each plot of the same weight of roots. The weight of roots and grains together increasezd in the order of kyun>kyunam>kyong, considering each treatment of experimental plot. The weight of grains was in relation to the minimum water content ratio during the midperiod of surface drainage and the average earth temperature was mainly affected by the minimum water content ratio because it was relatively increased in proportion to the water content ratio(at less than 40%) 8. The weight ratio of straw to grain showed an increasing tendency at the plot of shallow depth and had a relation of an inversely exponental function to the weight of roots. At the same depth of plot except the 15cm plot, the weight ratio of straw to grain was increased in proportion to the depth of consumptive water. The weight of grains was increased as the depth of consumptive water was increased to some extent, but at the same time the weight of ratio of straw to grain was increased. 9. At a certain texture of soils the increase in the amount of the cracks depends on meteorological conditions, especially increase in amounts of pan evaporation. So if it rains during the progressing of field drying the cracks largely decrease. The amount of cracks of clay soil had relation of inversely exponental function to the water content ratio(at more than 25%). The maximum depth of crack kept generally a constant value at less than 30% of water content ratio. 10. The cone index showed the tendency that it was propertional to the amount of cracks within a certain limit but more or less inversely proportional over a certain limit. The water content ratio at the limit may be about 25%. 11. The increase in the cone index with the progressing of time after final surface drainage showed the tendency that it was proportional to the depth of consumptive water at the last half of growing period. Based on the same depth of if the cone index in the kyunam plot was much larger than in the other two plots and that in the kyong plot was much smaller than in the kyun plott, as long as the depth of plot was deeper, especially in the 35-kyong plot. 12. In the light of a situation where water content ratio of soil decreased and the cone index increased after final surface drainage the porogress of the field dryness was much more rapid in the kyunam plot than in the kyong plot and the kyun plot, especially slowest in the kyong plot. In the plot with deeper zone the progress was much slower. The progress requiring the value of the cone index, $2.5kg/cm^2$, that working machinary can move easily on the field changed with the time of final surface drainage and the amount of rainfall, but without nay rain it required, in the kyunam plot, about 44mm in total amount of pan evaporation and more than 50mm in the other two plots. Therefore the drying in the kyunam plot was generally more rapid in the kyunam plot was generally more rapid over 2days than in the kyun plot, and especially may be more rapid over 5days than in the 35-kyong plot.

• The Korean Journal of Pesticide Science
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• v.13 no.1
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• pp.1-12
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• 2009

To assess the effect of butachlor on freshwater aquatic organisms, acute toxicity studies for algae, invertebrate and fishes were conducted. The algae grow inhibition studies were carried out to determine the growth inhibition effects of butachlor (Tech. 93.4%) in Pseudokirchneriella subcapitata (formerly knows as Selenastrum capriconutum), Desmodesmus subspicatus (formerly known as Scendusmus subspicatus), and Chlorella vulgaris during the exposure period of 72 hours. The toxicological responses of P. subcapitata, D. subspicatus, and C. vulgaris to butachlor, expressed in individual $ErC_{50}$ values were 0.002, 0.019, and $10.4mgL^{-1}$, respectively and NOEC values were 0.0008, 0.0016, and $5.34mg\;L^{-1}$, respectively. P. subcapitata was more sensitive than any other algae species. Butachlor has very high toxicity to the algae, such as P. subcapitata and D. subspicatu. In the acute immobilisation test for Daphnia magna, the 24 and $48h-EC_{50}$ values were 2.55 and $1.50mg\;L^{-1}$, respectively. As the results of the acute toxicity test on Cyprinus carpio, Oryzias latipes and Misgurnus anguillicaudatus, the $96h-LC_{50}s$ were 0.62, 0.41 and $0.24mg\;L^{-1}$, respectively. The following ecological risk assessment of butachlor was performed on the basis of the toxicological data of algae, invertebrate and fish and exposure concentrations in rice paddy, drain and river. When a butachlor formulation is applied in rice paddy field according to label recommendation, the measured concentration of butachlor in paddy water was $0.41mg\;L^{-1}$ and the predicted environmental concentration (PEC) of butachlor in drain water was $0.03 mg\;L^{-1}$. Residues of butachlor detected in major rivers between 1997 and 1998 were ranged from $0.0004mg\;L^{-1}$ to $0.0029mg\;L^{-1}$. Toxicity exposure ratios (TERs) of algae in rice paddy, drain and river were 0.004, 0.05 and 0.36, respectively and indicated that butachlor has a risk to algae in rice paddy, drain and river. On the other hand, TERs of invertebrate in rice paddy, drain and river were 3.6, 50 and 357, respectively, well above 2, indicating no risk to invertebrate. TERs of fish in rice paddy, drain and river were 0.58, 8 and 57, respectively. The TERs for fish indicated that butachlor poses a risk to fish in rice paddy but has no risk to fish in agricultural drain and river. In conclusion, butachlor has a minimal risk to algae in agricultural drain and river exposed from rice drainage but has no risk to invertebrate and fish.