• Korean Journal of Fisheries and Aquatic Sciences
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• v.13 no.4
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• pp.179-183
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• 1980

The efficiency of energy transfer by a population of the farmed pacific oyster, Crassostrea gigas was studied during culture period of 10 months July 1979-April 1980, in Geoje-Hansan Bay near Chungmu City. Energy use by the farmed oyster population was calculated from estimates of half-a-month unit age specific natural mortality rate and data on growth, gonad output, shell organic matter production and respiration. Total mortality during the culture period was estimated approximate $36\%$ from data on survivor individual number per cluster. Growth may be dual consisted of a curved line during the first half culture period (July-November) and a linear line in the later half period (December-April). The first half growth was approximated by the von Bertalanffy growth model; shell height, $SH=6.33\;(1-e^{0.2421(t+0.54)})$, where t is age in half-a-month unit. In the later half growth period shell height was related to t by SH=4.44+0.14t. Dry meat weight (DW) was related to shell height by log $DW=-2.2907+2.589{\cdot}log\;SH,\;(2, and/or log $DW=-5.8153+7.208{\cdot}log\;SH,\;(5. Size specific gonad output (G) as calculated by condition index of before and after the spawning season, was related to shell height by $G=0.0145+(3.95\times10^{-3}{\times}SH^{2.9861})$. Shell organic matter production (SO) was related to shell height by log $SO=-3.1884+2.527{\cdot}1og\;SH$. Size and temperature specific respiration rate (R) as determined in biotron system with controlled temperature, was related to dry meat weight and temperature (T) by log $R=(0.386T-0.5381)+(0.6409-0.0083T){\cdot}log\;DW$. The energy used in metabolism was calculated from size, temperature specific respiration and data on body composition. The calorie contents of oyster meat were estimated by bomb calorimetry based on nitrogen correction. The assimilation efficiency of the oyster estimated directly by a insoluble crude silicate method gave $55.5\%$. From the information presently available by other workers, the assimilation efficiency ranges between $40\%\;and\;70\%$. Twenty seven point four percent of the filtered food material expressed by energy value for oyster population was estimated to have been rejected as pseudofaeces : $17.2\%$ was passed as faeces; $35.04\%$ was respired and lost as heat; $0.38\%$ was bounded up in shell organics; $2.74\%$ was released as gonad output, $2.06\%$ was fell as meat reducing by mortality. The remaining $15.28\%$ was used as meat production. The net efficiency of energy transfer from assimilation to meat production (yield/assimilation) of a farm population of the oyster was estimated to be $28\%$ during culture period July 1979-April 1980. The gross efficiency of energy transfer from ingestion to meat production (yield/food filtered) is probably between $11\%\;and\;20\%$.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.11
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• pp.6958-6965
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• 2014

This study examined the occurring pattern of potential risky species and the related abiotic factors for port-specific environmental management considering the control of ballast water-induced foreign species at Incheon seaport. From a total of 62 species observed during the study, 13 red-tide and 7 toxic phytoplankton, normally occurring species in Korean waters, occurred from the seasonal investigation at the inner and outer sites of the Incheon seaport from 2007 to 2009. The number of potential risky phytoplankton was relatively high at the outer site of the port during summer and winter. Red-tide species, such as Skeletonema spp., Thalassiosira nordenskioldii, and Paralia sulcata, dominated the total standing crops at the inner site (avg. 72.4%) and outer site (avg. 77.6%) in spring and summer, being positively correlated with the concentrations of total suspended solids (TSS) and pH (p<0.05). In summer, the red-tide species (Skeletonema spp.) and toxic species (Alexandrium catenella, A. tamarense, Dinophysis acuminata and Pseudo-nitzschia spp.) co-dominated (avg. 74.2%) at the inner site, while Skeletonema spp. and P. sulcata predominated (avg. 67.2%) at the outer site. During the study periods, the toxic species were significantly and positively correlated with the chemical oxygen demand (COD), dissolved inorganic nitrogen, silicate and phosphate (p < 0.05). The chlorophyll-a (chl-a) concentration of phytoplankton at the outer site ranged from 1.49 to $5.46{\mu}g/L$ on average, which was 3-5 times higher than that at the inner site in spring, summer and autumn, whereas there was no difference in the concentration between inner (avg. $0.94{\mu}g/L$) and outer (avg. $0.95{\mu}g/L$) sites in winter. In summary, diverse red-tide species dominated and a relatively high chl-a concentration existed at the outer site, whereas a relatively high number of toxic species and low chl-a concentration was observed at the inner site in summer. The potential risky species can outbreak in association with the concentration of nutrients, COD and TSS, suggesting that distinctive management of potential risky species is needed considering the environmental characteristics of Incheon seaport.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.10
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• pp.1407-1413
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• 2005

An experiment was conducted in order to assess the effect of level of RDP:UDP ratio and level of feeding concentrate on milk yield, milk composition and nutrient utilization in lactating crossbred cattle. Twenty four medium producing (-10 kg/d, 45 to 135 days postpartum) lactating crossbred cows were divided into four groups of six animals each in a 2${\times}$2 factorial completely randomized design. The cows in group 1 were fed concentrate mixture I containing 59:41 RDP:UDP ratio (low UDP) at normal plane (LUDP+NP), in group 2 were fed low UDP ration at 115% of NRC (1989) requirements (LUDP+HP), whereas cows in group 3 were fed concentrate mixture II containing 52:48 RDP:UDP ratio (high UDP) at normal plane (HUDP+NP) and in group 4 were fed high UDP ration at 115% of NRC (1989) requirements (HUDP+HP). Green jowar was fed ad libitum as the sole roughage to all the animals. The experimental feeding trial lasted for 105 days. The total dry matter intake (DMI), DMI/100 kg body weight, DMI/kg $W^{0.75}$, digestibilities of DM, OM, CP, CF, EE and NFE and intakes of TDN and DCP did not differ significantly among the different groups and also due to both UDP level and plane of nutrition and also due to their interaction. The total dry matter intake varied from 145 g in group 1 (LUDP +NP) to 152.57 g/kg $W^{0.75}$ in group 2 (LUDP+HP) diet. However, increase in milk yield with increased UDP level and also with increased plane of nutrition was observed consistently throughout the experimental period. The average milk yield was 7.66, 8.15, 8.64 and 9.35 kg in groups 1, 2, 3 and 4, respectively and there was no significant difference in milk yield among different groups of cows. The overall daily average milk yields in cows fed with low and high UDP diets were 7.91 and 8.99 kg, respectively and at normal and higher plane of feeding the milk yields were 8.15 and 8.75 kg/day, respectively. Thus, there was 13.65% increase in milk yield due to high UDP level and 7.36% due to higher plane of feeding. The daily 4% FCM yields were 9.20 kg for low UDP diet and 10.28 kg for high UDP diet, whereas it was 9.11 kg at normal plane of feeding and 10.37 kg at higher plane of feeding. Fat yields for the corresponding treatment groups were 0.37, 0.43, 0.41 and 0.48 kg, respectively. The 4% FCM yield and also fat yield did not differ significantly among different dietary treatments and also due to UDP level and plane of nutrition, however, 4% FCM yield was increased by 11.74% with high UDP level and 13.83% with higher plane of feeding. The values for total solids, fat, lactose, solids-not-fat and gross energy contents in milk differed significantly (p<0.05) among the different groups and were significantly (p<0.05) higher in milk of cows fed LUDP+HP diet followed by HUDP+HP diet. Total solids (14.65 and 13.83%), lactose (5.44 and 4.92%), solids-not-fat (9.44 and 8.83%) and gross energy (887 and 838 kcal/kg) of milk decreased significantly (p<0.05) with increased UDP level while total solids (13.84 and 14.64), fat (4.84 and 5.36%) and gross energy (832 and 894 kcal/kg) increased significantly (p<0.05) with increase in plane of feeding. Gross and net energetic efficiencies and also gross and net efficiencies of nitrogen utilization for milk production were not significantly different among different groups and also were not affected significantly due to either UDP levels or plane of feeding. Results of the present study suggest that, increasing UDP level from 41% to 48% of CP in concentrate mixture and also increasing plane of feeding from normal (100%) to 115% of NRC requirements maintain a consistently higher milk production.

• Asian-Australasian Journal of Animal Sciences
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• v.12 no.3
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• pp.400-410
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• 1999

Five experiments were conducted using finishing pigs (PIC L326 sires $\times$ C15 dams) to examine the effects of expander operating conditions on nutrient digestibility in finishing pigs. The effects of different expanding conditions (0, 11.7, 24.4, $32.5kg/cm^2$) for corn-SBM based diets (Exp. 1), wheat meddlings diet (Exp. 2), sorghum-SBM based diets (Exp. 3) and wheat-SBM based diet (Exp. 4). Exp. 5 was conducted as a $2{\times}4$ factorial arrangement and factors examined were 2 soy products (raw soybean and SBM) and 4 expanding conditions (0, 14.1, 28.1, $42.2kg/cm^2$). In experiment 1, total production rates (p>0.10) were similar among treatments. The amount of fines decreased (cubic effect, p<0.001) as cone pressure was increased from 0 to $11.7kg/cm^2$, with smaller differences as cone pressure was further increased to $35.2kg/cm^2$. Nutrient digestibilities increased (p<0.02) as the feed was subjected to higher cone pressures. Digestibilities of DM, N, and GE were maximized at $24.4kg/cm^2$ cone pressure. The DE of the diet expanded at 24.4 and $35.2kg/cm^2$ increased by 172 and 109 kcal/kg, respectively, compared to the diet processed at $0kg/cm^2$ cone pressure. In experiment 2, total production and screened pellets production rates were similar among the processing treatments (p>0.21). The amount of fines decreased (quadratic effect, p<0.03) by 9 kg/h as cone pressure was increased from 0 to $11.7kg/cm^2$. Digestibilities of DM (p<0.02), N (p<0.001), and GE (p<0.002) were increased as cone pressure was increased from 0 to $35.2kg/cm^2$. DM, N, and GE digestibility in the pigs fed the midds-based diet increased by 8, 13, and 10%, respectively, at the highest processing cone pressure compared to the diets without any cone pressure. In experiment 3, the conditioned mash moistures for the treatments were numerically similar around 15% moisture. As the expander cone pressure was increased from 0 to $11.7kg/cm^2$, energy consumption for the pellet mill decreased (quadratic effect, p<0.004) from 14.1 to 12.0 kWh/t. Dry matter and gross energy digestibility increased (cubic effects, p<0.006) as cone pressure was increased from 0 to $35.2kg/cm^2$ with the largest improvement occurring as cone pressure was increased from 0 to $11.7kg/cm^2$. Nitrogen digestibility increased (cubic effect, p<0.001) from 78.3 to 81.0% as the feed was subjected to the higher cone pressures, with N digestibility being maximized at $24.4kg/cm^2$ cone pressure. The DE of the diet increased (cubic effect, p<0.001) by 225 kcal/kg as cone pressure was increased from 0 to $11.7kg/cm^2$. In experiment 4, pellet moisture decreased and moisture loss increased as cone pressure was increased from 0 to $35.2kg/cm^2$. Also, starch gelatinization of the wheat-based diets increased from 16.8 to 49.1% as the diets were processed at 0 and $35.2kg/cm^2$ cone pressure. Nutrient digestibilities were not affected (p>0.18) by any increase in cone pressure. In experiment 5, pellet moisture decreased as cone pressure was increased 0 to $35.2kg/cm^2$. The amount of moisture loss for the diets expanded at $42.2kg/cm^2$ was 3.0 and 3.8% for the SBM and raw soybean (RB) diets, respectively. Starch gelatinization for the SBM diets were 19% greater than the RB diets. The RB diets had lower DM, N and GE digestibilities as compared to the SBM diets. The DE of the RB diets were lower (p<0.02) than the SBM diets. DM (p<0.06), N (p<0.02), and GE (p<0.001) digestibilities of the dietary treatments increased as cone pressure was increased 0 to $42.2kg/cm^2$.

• Applied Biological Chemistry
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• v.44 no.2
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• pp.73-80
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• 2001

Factors such as temperature $(20,\;60^{\circ}C)$), pH (4.5, 7.0), gaseous phase $(N_2,\;0_2)$, and light (0 lux, 5,000 lux), antioxidants and packaging conditions were investigated to study the effects of above factors on the chlorophyll components in spinach during storage. Regardless of other factors, as the storage temperature increased from $20^{\circ}C$ to $60^{\circ}C$ and pH decreased from 7.0 to 4.5, the contents of chlorophyll a and chlorophyll b in spinach decreased significantly (P<0.05). The amounts of chlorophyll a and chlorophyll b in spinach stored in nitrogen gas were significantly (P<0.05) lower than those in sample in oxygen phase. As the light intensity increased from 0 lux to 5,000 lux during storage, the contents of chlorophyll a and chlorophyll b in spinach significantly (P<0.05) decreased. The antioxidants reduced the degradation of chlorophyll a in a model system during dark storage by minimization of free radical oxidation. The effectiveness of antioxidants decreased as following orders; ${\alpha}-tocopherol$>ascorbic acid>${\beta}-carotene$>catechin>quercetin>rutin>kaempherol>caffeic acid>chlorogenic acid>p-coumaric acid>ferulic acid. The degradation of chlorophyll a in a model system during light storage was minimized by antioxidants due to the reduction of singlet oxygen oxidation. The antidiscoloring potential of antioxidants decreased as following orders; ${\beta}-carotene$>${\alpha}-tocopherol$>ascorbic acid>catechin>quercetin>rutin>kaem-pherol>caffeic acid>chlorogenic acid>p-coumaric acid>ferulic acid. The amounts of chlorophyll a and chlorophyll b in freeze dried spinach packed with polyethylene bag were significantly (P<0.05) lower than those in non-packed freeze dried spinach. The package of spinach in polyethylene bag with the combination of antioxidants could be used to minimize the degradation of chlorophyll components in spinach during storage.

• Journal of Applied Biological Chemistry
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• v.54 no.2
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• pp.126-134
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• 2011

In this study, the characteristics of alcohol fermentation using ripe Daebong persimmon juice were studied in static fermentation condition by Saccharomycess cerevisiae CS02 in an effort to develop new types of functional wine. Attempts were made to modify the ripe Daebong persimmon juice in order to find suitable conditions for alcohol fermentation. The modified ripe Daebong persimmon juice that was most suitable for alcohol fermentation contained $24^{\circ}brix$ of sugar supplemented with sucrose as a carbon source and 0.5 g/L of $(NH_4)_2HPO_4$ as a nitrogen source. After 9 days of fermentation at $25^{\circ}C$, $12.2{\pm}0.02%$ of alcohol was produced from the modified juice and its pH markedly decreased to $3.97{\pm}0.02$. The wine contained free sugar such as fructose ($0.12{\pm}0.02$ g/L), some organic acids such as malic acid ($35.92{\pm}0.24$ g/L), succinic acid ($8.12{\pm}0.03$ g/L), oxalic acid ($22.14{\pm}0.11$ g/L), and citric acid ($13.63{\pm}0.08$ g/L), as well as some flavanols and phenolic acids such as catechin gallate ($38.99{\pm}0.32$ mg/L), epicatechin gallate ($110.21{\pm}0.16$ mg/L), gallic acid ($163.88{\pm}1.11$ mg/L), epigallocatechin ($15.97{\pm}0.18$ mg/L), and tannic acid ($13.36{\pm}0.02$ mg/L). In addition, the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical (84.25%) and $ABTS^{\cdot+}$ radical (99.65%) scavenging activities were increased significantly with a corresponding increased in the organic acid and phenolic acid contents, but decreased in the flavonoids.

• Journal of the Korea Organic Resources Recycling Association
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• v.23 no.2
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• pp.36-46
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• 2015

Integration of crop-livestock farming has been a problem-solving mode for abatement of environmental pollution and recovery of resources in recent years. The objectives of this study were 1) to suggest the customized integration of crop-livestock farming model reflecting the regional characteristics through in-depth analysis of case study and 2) to analyze the livestock nutrients flow in terms of three primary elements as nitrogen(N), phosphorous(P), and potassium(K). The personal interview and survey were carried out in 2012 for a total of 161 farms from four different regions(NS, NW, JJ, YC) in South Korea. The mass balance analysis was used to suggest and evaluate the models for two sites(JJ and YC). The results showed that NS and NW sites produced relatively more livestock manure than the sites of YC and JJ because of the regional differences in livestock numbers and urbanization. The models were suggested for the site JJ and site YC, and 'two track model(energy and resource recovery)' and 'dispersal type model' were assigned respectively. For the nutrient flows, the releasing P and K with new models had increased up to 7%, while N release had decreased down to 15% in both YC and JJ sites compared to the present treatment system. Estimated value showed that there was oversupply of N (719 ton/yr) and $P_2O_5$ (1,269 ton/yr) in YC and deficiency of N (671 ton/yr) and excessive $P_2O_5$ (32 ton/yr) in JJ respectively. Therefore, P runoff has to be considered an eutrophication occurs in rural small stream when an integration of crop-livestock farm system is applied into both sites.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.3
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• pp.429-436
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• 1998

A bacteriological study of sea water and oyster in Charan Bay was conducted to evaluate sanitary conditions of the bay and compliance of waters with the recommended bacteriological criteria for the designated area of shellfish cultivation, The Samples were collected at 23 sampling stations(Fig. 1 and Fig. 2) estaslished once a month from January 1997 to December 1997, During the study period, temperature ranged from 4.7 to $25.6^{\circ}C$, transparency ranged from 3.3 to 6.2m chemical oxygen demand ranged from 1.67 to 2.18 mg/$\ell$, dissolved oxygen demand ranged from 5.4 to 10.0 mg/$\ell$ dissolved nitrogen ranged from 1.65 to 7.88 $\mu$g-at/$\ell$, phosphate ranged from 0.15 to 1.16 $\mu$g-at/$\ell$, Chlorophylla-a ranged from 0.95 to 12.69mg/$\ell$. The coliform group and fecal coliform MPN's of sea water were ranged from <1.8$\~$l,600 and <1.8$\~$540, respectively. The coliform group and fecal coliform MPN's of oysters were ranged from <18$\~$16,000 and <18$\~$1,400, respectively. The viable cell counts in oyster ranged from $1.5\times10^2$ to $7.5\times10^3$. The bacteriological criteria of sea water in shellfish growing area should be less than 70 per 100 ml of sea water for median value of coliform MPN, and below $10\%$ of the samples which contain over than 230 for coliform MPN or over than 43 for fecal coliform MPN. The sea water from 432 samples were complied water coliform criteria recommended for designated shellfish growing area. The coliform group, fecal coliform, classification of coliform group with IMViC reactions and pathogenic vibrios were analyzed. During the study period, infectious bacteria such as Vibrio cholerae, Salmonella sp, and Shigella sp, were not detected from the samples, but detection ratios of Vibrio parahaemolyticus and Vibrio vulnifirus were $7\~17\%$ in summer months.

• Journal of Korean Society of Environmental Engineers
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• v.38 no.8
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• pp.420-427
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• 2016

This study was conducted on the sediment remediation using micro-bubble to remove fine particles. For this study, characteristics of contamination and release in sediment were analyzed. And then, the characteristics of bubbles on removal efficiency was investigated at various operation conditions. In particle size distribution of the sediment used for the study, the proportion of clay and silt (<0.075 mm) was about 7.7%, sand (0.075~4.75 mm) was about 67.8%, and gravel (${\geq}4.75$) was 24.5%. Total nitrogen (TN) and total phosphorus (TP) of the sediment were 2,790~3,260, 261~311 mg/kg respectively. Ignition loss and water content were 4.1~9.6, 32.9~53.2% respectively. In analysis of removal efficiency according to operation conditions of micro-bubble, it was the highest when operation condition is pressure 6 atm, pressurized water ratio 30%, and coagulant dosage 15 ppm. At the time, the sediment's removal efficiency was 19.9%. Accordingly removal efficiency of TN and TP were 21.4, 22.6% respectively. Finally a research was found that fine particles in sediment were almost removed by micro-bubble, which led to decrease nutrients' release at about 20.1~64.3% in comparison to sediment including lots of fine particles.

• Korean Journal of Weed Science
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• v.12 no.3
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• pp.200-222
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• 1992

The results of recent researches for improvement of seedling stand in direct seeded rice on the dry paddy in Korea were summarized as the following ; a variety to be cultivated should be chosen the characteristics of high percentage germination under low temperature, shorter period of shoot emergence, and better growth of the mesocotyl and shoots. Meanwhile, there was 40% increase in seedling stand at the treatment of removal of the seed awn under using the drill seeder. After seeding the rice seed covered with soil of 3cm depth was better seedling emergence and also there was the hightest seedling emergence at the 70% of moisture content of the soil. In addition, the application of the Release containing GA 10% enabled to increase the seedling stand and furthermore it was effective under deep seeding depth. The optimum seeding date should be seeded around May 10 when mean air temperature is above 12-13$^{\circ}C$ so that may establish more less 70% in seedling stand. Based on an appropriate seedling stand of 150/$m^2$, the optimum seeding rate was 5kg/10a. It was the best in seeding method using drill seeder and the most desirable recommended seeding method was the drill seeder in terms of seedling stand. In order to improve seedling stand water management was more effective in canal irrigation and in drainage at 6hr after irrigation following by the seeding process. On the other hand, for the increase of seedling stand under flooded condition a variety might have characters being better germination at low concentration of dissolved oxygen and vertically deeper growing of the crown root. Also, seedling stand was able to increase with the seed coating of $CaO_2$in the flooded soil. It was possible to be seeded on the early part of May being mean air temperature of avove 10$^{\circ}C$ and the optimum seeding rate was 5kg/10a. For an effective water management water would be flooded up to 3cm depth for 2-3 weeks after seeding. The rice plant grown under the direct seeded cultivation might be not so much strong in lodging resistance compared to that grown under the transplanting and moreover direct seeded rice cultivation under flooded condition would be more weak growth of the rice plant than that on dry paddy. Meanwhile, the lodging would be affected by the seeding rate, the soil depth after seeding. and seeding method even in the same variety. In particular, roots in the lodging pattern of direct seeded rice cultivation under flooded condition were largely distributed on the soil surface so that resulted easily in the lodging. In general, the lodging resistance would be greater as seeding rate and amount of N fertilizer application are lower and soil depth after seeding is higher. Among the introduction of different seeding method the high ridged drill seeding method on dry paddy soil resulted in the lowest in the lodging index and also it was lower in the drill seeding method than in the scattering seeding method under flooded condition. In case of more than 150 seedlings per $m^2$ there was a severe lodging due to high lodging index at the 3rd and 4th internodes. The effective lodging prevention was able to at the treatment of the Inabenfide at 45 days before heading and the Uniconazol at 15 days before heading which caused the shortage by 10-15cm in culm length. Also, fertilizer management using split application of nitrogen would be contributed the reduction of lodging at the rate of 20-30-20-20-10%(basal-5th leaf stage-7th leaf stage-panicle initiation stage-heading stage) on the dry paddy soil.