• Animal cells and systems
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• 제8권4호
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• pp.281-288
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• 2004

The change in relationships between methane production and sulfate reduction was investigated in reclaimed rice field soils at different time points after reclamation of tidal flat in Korea. Sulfate concentrations of soils in the ca. 60-year-old and 26-year-old reclaimed rice fields were much lower than that in a natural tidal flat. During 60 d of anaerobic incubation, total methane production and sulfate consumption of the soil slurries were 7.0 ${\mu}$mol $CH_4$/g and 8.2 ${\mu}$mol $SO_4^{2-}$/g in the 60-year-old rice field, 5.6 ${\mu}$mol $CH_4$/g and 12.7 mmol $SO_4^{2-}$/g in the 26-year-old rice field, and ca. 0 mmol $CH_4$/g and 22.4 ${\mu}$mol $SO_4^{2-}$/g in a natural tidal flat. Relative percent electron flow through sulfate reduction in the 60-year-old rice field was much lower (50.8%) compared with the 26-year-old rice field (69.3%) and the tidal flat (99.9%). The addition of an inhibitor of methanogenesis (2-bromoethanesulfonate) had no effect on sulfate reduction in the soil slurries of the reclaimed rice fields. However, instant stimulation of methane production was achieved with addition of an inhibitor of sulfate reduction (molybdate) in the soil slurries from the 26-year-old reclaimed rice field. The specific inhibitor experiments suggest that the relationship of methanogenesis and sulfate reduction might become mutually exclusive or syntrophic depending on sulfate content in the soil after reclamation. Sulfate, thus sulfate reduction activity of sulfate-reducing bacteria, would be an important environmental factor that inhibits methane production and determines the major pathway of electron and carbon flow in anaerobic carbon mineralization of reclaimed rice field soils.

• The Korean Journal of Ecology
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• 제20권5호
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• pp.367-373
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• 1997

The effects of salinity on the growth and production of rice were studied at Seosan reclaimed land from July to October, 1995. The plant height, the number of living aleaves, dead leaves and total leaves, the number of the grains and the dry weight of the grains per individual, and the dry weight of above the ground in $25cm{\times}25cm$ quadrat were investigated on 5 plots whers were different salinity. The plant height, the number of living leaves and total leaves and the number of grains and the dry weight of grains per individual, and the dry weight of above the ground decreased as the salinity of water increase and the number of dead leaves of rice increased as the salinity of water decrease. The effect of salinity on the reproductive production is severer than the vegetative production. Because of the salinity, the growth and the production of the rice at Seosan reclaimed land are worse than the normal rice field.

• 한국작물학회지
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• 제67권4호
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• pp.326-334
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• 2022

This study was carried out to investigate the optimal nitrogen concentration level suitable for forage rice growth by hydroponic cultivation in the salinity concentration of 0.1~0.3% which is similar to that of Muan reclaimed paddy field, and based on this results, to estimate optimal nitrogen fertilization level by field experiment in Muan reclaimed paddy for maximum forage production by cultivation of Yeongwoo rice. As a result of the growth response to the salt and nitrogen concentrations in the hydroponic cultivation experiment, the growth amount increased as the nitrogen concentration increased in the range of 0~24 me/L in the absence of salt stress. However, at a salt concentration of 0.1~0.3%, the growth amount was the highest at a nitrogen concentration of 12 me/L, and at higher nitrogen concentrations of that, the rice growth decreased as the nitrogen concentration increased. Therefore, nitrogen concentration of 12 me/L was judged to be an appropriate concentration for forage rice growth at salt concentration of 0.1~0.3%, and a nitrogen fertilization amount level corresponding to a nitrogen concentration of 12 me/L was actually applied to the Muan reclaimed paddy field for forage rice cultivation during two years. The amount of nitrogen fertilizer was tested with three treatments, which are 18 kg/10a considered appropriate, and 1.5 times and 2 times of the appropriate amount, and the planting density was tested with 2 treatments of 15 hills/m² and 26 hills/m². As a result of the reclaimed paddy field experiment, the yield was the highest when nitrogen fertilizer was applied at 18 kg/10a in the planting density of both treatments. Looking at the yield according to planting density, the high planting density plot yielded higher than the low planting density plot. In other words, when the planting density was 26 hills/m² and the nitrogen fertilization amount was 18 kg/10, the highest dry matter yield of 1,763 kg/10a was obtained. From the results of hydroponics and reclaimed field experiments, we could conclude that the productivity of forage rice decreased more as the nitrogen concentration increased when the nitrogen concentration was higher than the optimal level under salt stress.

• 한국농공학회지
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• 제44권7호
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• pp.14-24
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• 2002

The effect of reclaimed water irrigation on paddy rice culture was evaluated by pilot study at the experimental field of Konkuk University in Seoul, Korea. The sewage was treated by constructed wetland system, and its effluent was used as irrigation water for four treatments and one control plots with three replications. Irrigation of reclaimed water onto paddy rice cultures did not adversely affect the growth and yield of rice. Instead, experimental rice plots of reclaimed water irrigation displayed about 10 to 50% more yield on average than controls. This implies that reclaimed water irrigation might be beneficial rather than harmful to rice culture as long as the sewage is treated adequately and used properly. The amount of irrigation water had little effect on experimental rice cultures, but its strength was important. The strength of treated sewage was not a limiting factor in this study, and no lodging was observed even with a relatively high nitrogen concentration (up to 160mg/L). In general the paddy soil was not affected by reclaimed water irrigation. However, there was an indication that continuous irrigation with high strength of reclaimed water might cause salt accumulation in the soil. Supplemental use of reclaimed water with existing sources of irrigation water is recommended rather than irrigation with a single source of reclaimed water. Overall, the results demonstrated that reclaimed water could be reused as a supplemental source of irrigation water for paddy rice culture without causing adverse effects as long as it is properly managed. For full-scale application, further investigation should be done on environmental risks, tolerable water quality, and fraction of supplemental irrigation.

• 한국농공학회지
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• 제42권3호
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• pp.66-75
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• 2000

Effect of reclaimed sewage on the paddy rice culture was examined by field experiment for two consecutive years. The domestic sewage was treated by the constructed wetland and the effluent of the treatment wetland was used for irrigation water. The reclaimed sewage was diluted before irrigation in the first year and it was used without dilution in the second year experiment. Growth components and yields were compared against the control plot where conventional method was applied. And also soil characteristics of the plots before and after reclaimed sewage irrigation were analyzed Generally addition of the reclaimed sewage irrigation didn't affect paddy rice culture adversely and even enhancement was observed. Fertilization was thought to be important factor for rice culture rather than irrigation water quality. Conventional fertilization and reclaimed sewage irrigation which contained high nutrient concentration resulted in better growth and more yield. Unlike widespread concern lodging did not happen even in the case of irrigation with average 90mg/L of T-N and conventional fertilization. Soil characteristics changed after irrigation and significant EC increasing was observed for the reclaimed sewage irrigation plots. From soil analyses salt accumulation could be a more potential problem than nutrients like nitrogen and phosphorus in the use of reclaimed sewage irrigation. Overall reclaimed sewage irrigation was thought to be one of practical alternatives for the ultimate disposal of sewage in rural area.

• 한국토양비료학회지
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• 제48권3호
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• pp.205-212
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• 2015

Farmers with forage barley (Hordeum vulgare L.)-rice (Oryza sativa L.) cropping system at reclaimed tidal lands burn crop residues to facilitate seedbed preparation or remove them for feed stock. This study was conducted to investigate the effect of rice straw amendment and N fertilization on soil properties and N uptake of rice under forage barely-rice cropping system at reclaimed tidal paddy field. Rice straw was applied at the rates of 0, 2.5 and $5.0ton\;ha^{-1}$ and N was fertilized at 0, 100, 200 and $400kg\;ha^{-1}$. Although there was no significant difference in the growth and yield of rice, fresh and dry weight of forage barely increased with increasing the amount of rice straw. The amount of N uptake of rice at harvesting stage was $65.8-69.2kg\;ha^{-1}$ by the amount of rice straw amendment, but there were no significant differences among rice straw amendment levels. After harvesting the rice, the soil salinity decreased with rice straw amendment compared to the control. After forage barely and rice cultivation, soil organic matter contents increased to $2.6-2.8g\;kg^{-1}$ and $3.2-3.5g\;kg^{-1}$, respectively. The amount of N uptake of rice at harvesting stage increased up to $82kg\;ha^{-1}$ in $400kg\;ha^{-1}$ N applied plots which were $37.8kg\;ha^{-1}$ higher than the control. Nitrogen fertilization decreased N recovery efficiency. The highest yield of rice was observed at $244kg\;ha^{-1}$ N fertilization level, but the optimum N level was estimated at $168kg\;ha^{-1}$ in order to keep the protein content of rice under 6.5%. Further researches on N uptake and application of organic matter according to soil salinity will be necessary to increase N use efficiency at reclaimed tidal paddy field.

• 한국작물학회지
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• 제59권4호
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• pp.526-531
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• 2014

본 연구는 간척지에서 사료용벼를 재배하여 조사료를 생산함으로써 간척지 이용률 증진과 조사료생산의 두가지 가능성을 검토해보고자 일반답과 간척답에서 사료용벼를 재배하여 생육특성, 총체수량 및 사료가치 등을 조사하였다. 1. 출수기는 일반답에서 8월15일에서 8월30일, 간척답에서 8월14일에서 8월 29일이었으며, 간척답이 일반답보다 1~2일 빨랐으며, 목우는 일반답에서 8월 26일, 간척답에서 8월 27일로 수원 544호를 제외하고는 가장 늦었다. 2. 초장은 일반답에서 105~135 cm범위이었고, 간척답에서 97~126 cm범위였으며 일반답에서는 목양이 간척답에서는 수원544호가 가장 컸다. 주당경수는 일반답과 간척답 모두 녹양이 16개로 가장 많았고 총체수량은 일반답은 $15.26{\sim}23.24MT\;ha^{-1}$, 간척답은 $11.94{\sim}18.89MT\;ha^{-1}$범위이었으며 목우벼가 두지역에서 가장 많이 생산되었다. 각품종별 수량은 일반답에 비하여 78~84% 수준이었다. 3. 단백질 함량은 일반답에서는 녹양벼가 높았으나 간척답에서는 6.7~8.7%로서 상대적으로 낮은 수치를 보였고 목양벼가 8.7%로 가장 높았다. 각 품종별 NDF는 31.2~55.5% 수준을 나타냈으며 ADF는 일반답에 비하여 큰 차이를 보이지 않았으며 가소화 양분총량을 계산해본 결과 일반답에서 목우벼가 71.2%로 가장 높았고 전체적으로 60%이상의 함량을 보여 간척지에서 재배하여도 사료로서의 가치는 충분할 것으로 생각되었다. 4. TDN수량을 비교해본 결과 일반답에서 TDN수량은 목우벼가 $16.54MT\;ha^{-1}$로 가장 높았으며 간척답에서도 $12.69MT\;ha^{-1}$로 가장 높은 수량을 보였다. 5. 이상의 결과로 간척지에서 사료용벼를 재배할 경우 일반답에 비하여 80%정도의 수량을 보여 간척지에서 재배가능성을 확인하였으며 목우를 재배할 경우 수량 및 사료가치면에서 가장 좋을 것으로 생각된다.

• 한국토양비료학회지
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• 제18권2호
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• pp.215-220
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• 1985

숙전(熟田)과 신야산개간지(新野山開懇地) 토양(土壤)에서 유기물(有機物) 종류별(種類別) 시용(施用)이 땅콩의 생육(生育)과 수량(收量) 그리고 토양화학성(土壤化學性)에 미치는 효과(效果)를 검토(檢討)한 결과(結果)는 다음과 같다. 1. 숙전(熟田)에서는 신선(新鮮)한 유기물(有機物)인 볏짚, 왕겨 시용이 수량(收量)을 증가(增加)시켰으나 야산개간지(野山開墾地)에서는 퇴비(堆肥) 시용(施用)이 수량(收量)을 증가(增加)시켰다. 2. 야산개간전(野山開墾田)에서 C/N율(率)이 높은 볏짚, 왕겨 시용구(施用區)가 근류(根瘤) 착생량(着生量)이 많았다. 3. 유기물(有機物) 함량(含量)이 많을수록 야산개간전(野山開墾田)에서 수량(收量)이 증가(增加)되었으나 숙전(熟田)은 경향이 없었다. 4. 시험후(試驗後) 토양중(土壤中) 유기물(有機物) 함량(含量)은 숙전(熟田)에서는 변화(變化)가 없었으나 야산개간전(野山開墾田)은 약간 증가(增加)되는 경향(傾向)이었다.

• 한국작물학회지
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• 제47권3호
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• pp.259-262
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• 2002

간척지 논에서 고품질 쌀 생산을 위한 기초 자료를 얻고자 2001년 농업기반공사 김포간척지에서 9개 벼 품종의 수량과 단백질 함량 및 식미치의 관계를 검토한 결과는 다음과 같다. 1. 쌀 수량은 식미계에 의한 식미치와 고도로 유의한 부상관(r=-0.49$^{**}$ )을 나타내었다. 수량이 낮은 수라벼의 식미치가 가장 높았고 수량이 높은 대안벼와 진품벼는 식미치가 가장 낮았다. 2. 간척지 재배 백미의 단백질 함량은 모든 품종이 7.5% 이상으로 상당히 높은 편이었는데 이는 시비와 관개용수에서 많은 질소질비료가 공급된 결과로 보여졌다. 3. 김포간척지에 적합한 벼 품종은 수량성 면에서는 대안벼, 진품벼, 신동진벼이나 품질을 고려한다면 단백질 함량이 낮고 식미치가 높은 광안벼, 수라벼, 남평벼가 적합하다고 사료되었다.

• 농업과학연구
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• 제46권4호
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• pp.791-798
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• 2019

This experiment was conducted to find out the difference between roughage productivity and feed value by using two domestic forage rice cultivars in a mid-west reclaimed rice field in Korea. During the growing period, Na⁺ content in soil showed no significant difference between the two cultivars; however, the K⁺ content in the soil was significantly lower than that in which the Mogwo was grown. The tiller number was 45.5 to 58.8, which was higher than that of Mogyeong, and the leaf number was higher than that of Mogyeong. The dry matter yield per 10 a was 1,338 kg for Moggyang and 1,532 kg for Mogwoo. At the harvest time, the crude protein yield per 10 a produced 108 kg of Mogyang and 170 kg of Mogwoo, and the total digestion nutrient (TDN) yield per 10 a also produced about 617 kg of Mogyang and 880 kg of Mogwoo. To sum up the above results, Mogwo, which has many tiller numbers and leaf numbers, has a high dry matter production, a relatively low neutral detergent fiber (NDF) and acidic detergent fiber (ADF), and a high crude protein yield and TDN yield, and it was better when cultivating the forage rice cultivars in reclaimed land.