• 한국환경농학회지
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• 제34권4호
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• pp.253-259
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• 2015

BACKGROUND: During the off-season, the cultivation of Chinese cabbage and water dropwort is often used to desalinize plastic film house soils. The objective of this study was to verify the effect of double-cropping systems on the salt removal in oriental melon cultivated plastic film house soils.METHODS AND RESULTS: Electrical conductivity (EC) and soluble salt contents were measured in soils collected from plastic film houses of oriental melon cultivation before and after the off-season crop cultivation. Also the same measurements were performed in the next oriental melon season to estimate the desalinization effect of double-cropping systems. During the cultivation of Chinese cabbage under open-field condition, EC_eof surface soil was reduced from 6.0 to 0.8 dS/m. Double-cropping of water dropwort in flooded soil was also efficient in removing the salts accumulated during oriental melon cultivation. In the house soils where salts were removed during the off-season crop cultivation, soil EC_ewas maintained below 3 dS/m during the next oriental melon cultivation season.CONCLUSION: The off-season cropping under open-field or flooded condition was effective in desalinization of plastic film house soils. Since the salt removal effect is not expected to last for several years, the double-cropping system should be introduced every season to maintain soil EC below the critical level.

• 한국토양비료학회지
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• 제48권4호
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• pp.271-277
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• 2015

Anaerobic decomposition of organic material in flooded rice fields produces methane, which escapes to the atmosphere primarily by transport through the rice plants. The annual amount of $CH_4$ emitted from a given area of rice is a function of the number and duration of crops grown, water regimes before and during cultivation period, and organic and inorganic soil amendments. Soil type, temperature, and rice cultivar also affect $CH_4$ emissions. The field experiment was conducted for three years to develop methane emission factor for water regime before the cultivation period from the rice fields. It was treated with three different water regimes prior to rice cultivation, namely: non-flooded pre-season < 180 days, non-flooded pre-season > 180 days, flooded per-season in which the minimum flooding interval is set to 30 days. Methane emission increased with days after transplanting and soil redox potential (Eh) decreased rapidly after flooding during the rice cultivation. The average methane emission fluxes were $5.47kg\;CH_4\;ha^{-1}day^{-1}$in flooded pre-season > 30 days, 5.04 in non-flooded pre-season < 180 days and 4.62 in non-flooded pre-season > 180. Methane emission flux was highly correlated with soil temperature and soil Eh. Rice yields showed no difference among treatments with water regime before the cultivation period.

• International Journal of Industrial Entomology and Biomaterials
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• 제24권1호
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• pp.17-21
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• 2012

The effect of cultivation season on the cocoon filament quality of authorized silkworm variety, GoldenSilk was examined with cocoon filament character, reeling character, and fiber character during 3 years. In cocoon filament character, filament length of spring and autumn cocoon was 979 and 879 m, respectively. Cocoon filament weight of spring and autumn cocoon was 33.1 and 26.5 cg, which is lower than that of general bivoltine strain, BaeGokJam. Raw silk percentage of spring and autumn cocoon was 15.65 and 13.77%, respectively. In reeling character, reelability showed similar trend regardless of cultivation season and strain. However, the length and weight of non-broken filament of spring season were slightly higher than those of autumn cocoon. Cultivation season did not affect on the fiber characteristics such as clearness and neatness, lousiness, and degumming loss. In cocoon character, filament length, size, and weight, spring cocoon filament showed higher value than autumn cocoon, but lower than authorized general silkworm varieties. In reeling characteristics, non-broken length and weight showed the similar trends with the cocoon filament character. However, the reelability of GoldenSilk cocoon was not affected by cultivation season. The reelability of GoldenSilk cocoon was also similar with that of authorized general one. Fiber character including clearness and neatness, lousiness, and degumming loss was also similar regardless of the rearing season and different strain.

• 한국작물학회지
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• 제48권6호
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• pp.534-539
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• 2003

이앙기 및 수확시기에 따른 쌀 품질을 식미 관점에서 검토하여 고품질 쌀 생산을 위한 기초 자료를 얻고자 2001년 서진벼, 일품벼, 추청벼를 공시하여 인천광역시 서구 경서동에 위치한 농업기반공사 김포간척지에서 실험한 결과는 다음과 같다. 1. 현미수량은 이앙시기간 고도로 유의한 차이가 있어서 3품종 모두 조기, 보통기재배가 만기재배보다 수량이 유의하게 많았다. 2. 백미의 단백질 함량은 이앙기와 수확시기간 고도의 상호작용이 있어서 발의 단백질 함량이 저하되는 수확시기는 이앙기에 따라 달랐다. 3. 이앙기에 따른 식미값은 서진벼와 일품벼는 조기와 만기재배에서 유의하게 높으나 추청벼는 만기재배에서도 떨어지지 않는 경향이었다. 4. 백미의 식미치는 등숙적산기온과 고도로 유의한 부의 상관(-0.43$^{**}$ )이 있어서 적산기온이 높을수록 식미치가 저하하였다. 5. 수량과 품질을 동시에 고려할때 조기 또는 보통기재배를 하되 수확시기는 출수후 40일로 다소 빠르게 하는 것이 유리한 것으로 판단되었다.

• 한국토양비료학회지
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• 제49권4호
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• pp.335-340
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• 2016

Soil organic carbon plays an important role on soil physico-chemical properties and crop yields in paddy soil. However, there is little information on the soil organic carbon under different forage cultivation during winter season in rice paddy. In this study, we investigated the soil organic carbon and physico-chemical properties in 87 fields of paddy soil cultivated with Barley, rye, and Italian ryegrass (IRG) as animal feedstock during winter season. Organic carbon was 12.9, 14.3, and $16.9g\;C\;kg^{-1}$ in soil with barley, rye, and IRG cultivation, respectively. Among rice-forage cultivation systems, the rice+IRG cropping system was 19.5% higher than in the mono-rice cultivation. Bulk density ranged from 1.17 to $1.28g\;cm^{-3}$ irrespective of cropping systems, and had strongly negative correlation with the soil organic carbon in the rice+IRG cropping system. Carbon storage in rice+IRG cropping systems was average $29.6Mg\;ha^{-1}$ at 15 cm of soil depth, which was 20.4 and 10.3% higher than those of barley and rye cultivation. Increasing carbon storage in paddy soil contributed to the fertility for following rice cultivation. This results indicated that IRG cultivation during winter season could be an alternative and promising way to enhance soil organic carbon content and fertility of paddy soil.

• 한국토양비료학회지
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• 제7권2호
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• pp.99-105
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• 1974

진흥(振興)과 IR667-수원(水原) 214의 작기이동재배(作期移動栽培)에서 출수기(出穗期)와 출수(出穗)4주후(週後)에 절위별(節位別) 엽초(葉鞘) 및 절간(節間)의 당(糖) 및 전분함량(澱粉含量)에 따라 탄수화물대사(炭水化物代謝)에 있어 고당형(高糖形)(당(糖)>전분(澱粉)), 당경향(糖傾向)(당함량증가경향(糖含量增加傾向)), 고전분형(高澱粉形)(전분(澱粉)>당(糖)), 전분경향등(澱粉傾向等) 분류(分類)의 타당성(妥當性)을 재검토(再檢討)한 결과(結果) 다음과 같다. 1) 진흥(振興)보다 IR667이, 엽초(葉鞘)보다 절간(節間)이, 조기(早期)보다 만기(晩期)가 출수기(出穗期)보다 4주후(週後)가 저온(低溫)에서보다 고온(高溫)에서 당경향(糖傾向)이었다. 따라서 출수기(出穗期)에는 조기(早期) 및 만기재배(晩期栽培)의 진흥엽초(振興葉鞘)와 절간(節間)이 고전분형(高澱粉形)이고 조기(早期) IR667의 하위절간(下位節間) 및 만기(晩期) IR667의 엽초(葉鞘)와 절간(節間)은 고당형(高糖形)이었다. 극만기(極晩期)에서는 진흥출수기제(振興出穗期第)1절간(節間)을 제(除)한 두 품종의 모두 절간(節間)이 고전분형(高澱粉形)이었다. 출수(出穗)4주후(週後)에는 진흥(振興)의 제1(第) 및 4위엽초(位葉鞘)를 제외(除外)한 두품종의 모든 엽초(葉鞘)와 절간(節間)이 고당형(高糖形)이었다. 조기(早期) IR667과 만기(晩期) 두품종이 출수(出穗)4주후(週後)에 절간(節間) 보다 엽초(葉鞘)에서 고당형(高糖形)이 강화(强化)되었다. 2) 상위(上位)3절위(節位) 엽초(葉鞘) 및 간(稈)이 탄수화물전류(炭水化物轉流)에서 같은 방향(方向)으로 작용(作用)하는 것 같다. 그들간엔 상위(上位)로 갈수록 출수기(出穗期)에는 당경향(糖傾向)을, 4주후(週後)에는 전분경향(澱粉傾向)을 보이며 이러한 현상은 진흥(振興)에서 뚜렷하였다. 3) 작기(作期)가 늦을수록 탄수화물함량(炭水化物含量)(당(糖)+전분(澱粉))이 높고 이 경향(傾向)은 출수(出穗)4주후(週後)와 IR667에서 뚜렷하여 저온(低溫)에 의(依)한 전류조해(轉流阻害)를 나타내는것 같다. 4) 수(穗)로의 전류속도(轉流速度)(일당입중증가(日當粒重增加))는 단기재배(單期栽培)에서 빠르고 진흥(振興)보다 IR667이 빨리 최고속도(最高速度)에 도달(到達)하였다. 5) 작기(作期)가 늦을수록 수량(收量)에 대(對)한 출수전(出穗前) 탄수화물(炭水化物)의 기여율(奇與率)은 커지며 엽초중심형(葉鞘中心形)인 IR667이 언제나 컸다. 6) 당(糖)/전분비(澱粉比)는 주(主)로 품종(品種)의 대사특성(代謝特性)으로, 이차적(二次的)으로 그러나 상당한 정도로 환경요인(環境要因)에 의하여 결정(決定)되는것 같다.

• Journal of Ginseng Research
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• 제15권1호
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• pp.36-40
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• 1991

A field experiment was conducted to examine the growth of one and two year old American ginseng (Panax guinguefolium L.) in the arid interior of British Columbia, Canada. For both years of plants, early season growth was characterized by rapid stem and leaf dry matter production. Root growth commenced in early June and continued until early September. One year old roots had a dry weight of 0.1 to 0.2g at the end of the growing season. The two years old roots commenced the growing season at 0.Is and increased in dry matter by a factor of ten-fold. Dry to fresh weight ratios for both years were similar for root, leaf and stem samples at the end of the growing season. Leaf area index for both years showed similarities in progression over the growing season. As a consequence of the effectiveness of the microclimate modification employed to permit American ginseng cultivation (elevated shade cloth and surface mulch), plant growth and development was extremely good. This indicates the potential for the cultivation of American ginseng in dryland environments.

• 한국연초학회지
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• 제5권1호
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• pp.73-78
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• 1983

In order to investigate the relation between weather factors, soil water, and tobacco yield grown by nonnulching and mulehing cultivations, a regression analysis was conducted for data collected from 8 years (1971 to 1978) for a flue-cured variety of Hicks. The soil water was calculated by Smith's method. 1 . Tobacco yield was largely correlated to soil water deficit during draught time for nonmulclung cultivation; $Y=6.146+8.6185\times-0.0925$\times2(R=0.935)^{***})$ 2. Tobacco yield was more largely correlated to soil water in flexible draght time interval than in fixed time interval during maximum growing phase.3. This field test was supposed that the optimal soil water condition was 65%field caps city. In this condition tobacco yield was 197. 1-216.5kg/10a for non-mulching cultivation. But the soil water deficit in draught season was little matter for mulching cultivation. The relation between xield and evaporation during May to June was Y: -1199.55+9.4 353$\times$:O. 0155$\times$2 (R=0.904") Maximum tobacco yield was expected to 223.6-251.4kg/10a for mulching cultivation. 5 . Tobacco required high temperature and light even in drying season (maximum growing phase) for mulching cultivation.tion.

• 한국버섯학회지
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• 제17권3호
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• pp.93-98
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• 2019

We investigated the correlation between density of air and the infection rate of airborne microorganisms in mushroom cultivation facilities and found that the correlation was low in places where the infection rate during cultivation was less than 1%. The farms with an infection rate of 2~5% showed a high infection rate in the inoculation room in spring and summer seasons, and in the incubation room in autumn, and the farms with an infection rate of more than 6% showed infection in all the rooms regardless of the season. The farms where the Trichoderma sp. was investigated at the time of the mushroom cultivation showed the highest infection rates of 3.17%, 2.74%, and 2.64% in summer, spring, and autumn, respectively. The farms infected with Neurospora tetrasperma showed a lesser rate of infection than the ones infected with Trichoderma sp., and the highest infection rate of 0.56% was observed in summer. Based on these results, the type of infection could be classified into five groups, where type I was farms where the infection rate is less than 1% in all seasons. Three farms belonged to this type, and the infection rate in this type was lower than that in the other types.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.319-319
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• 2017

Methane is the main greenhouse gas released from rice paddy field. Methane from paddy fields accounts for 11 % of the global total methane emission. The global warming potential (GWP) of methane is 25 times more than that of carbon dioxide on a mass basis. It is well known that most effective practice to mitigate methane in paddy is related to the water management during rice growing season and the use of organic matters. This study was conducted to investigate the effects of tillage and cultivation method on methane emission in paddy. Tillage (tillage and no-tillage) and cultivation methods (transplanting and direct seeding) were combined tillage-transplanting (T-T), tillage-wet hill seeding (T-W), tillage-dry seeding (T-D) and no-till dry seeding (NT-D) to evaluate methane mitigation efficiency. Daily methane emission was decreased on seeding treatments (T-W, T-D, NT-D) than transplanting treatment (T-T). Amount of methane emission during rice growing season is highest in T-T ($411.7CH_4\;kg\;ha^{-1}y^{-1}$) and lowest in NT-D treatment (89.7). In T-W and T-D treatments, methane emissions were significantly decreased by 36 and 51 % respectively compared with T-T. Methane emissions were highly correlated with the dry weight of whole rice plant ($R^2=0.62{\sim}0.93$). T-T treatment showed highest $R^2$ (0.93) among the four treatments. Rice grain yields did not significantly differ with the tillage and cultivation methods used. These results suggest that direct seeding practice in rice production could mitigate the methane emissions without loss in grain yield.