• Journal of Wetlands Research
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• v.20 no.2
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• pp.116-123
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• 2018

The objective of this study was to examine effects of stand age on soil $CO_2$ efflux in plantation Pinus koraiensis, and to elucidate what extent plant (fine) root and soil microbial biomass contribute to the whole soil $CO_2$ efflux. In three age classes (20-yr-old. 40-yr-old, 70-yr-old) of plantation Pinus koraiensis, in-situ soil respiration, plant fine root biomass and soil microbial biomass were measured from April to November in 2004. Regardless of stand age, soil temperature and soil $CO_2$ efflux increased until July then slowly decreased. Soil respiration was higher in 70-yr-old stand than in 20- and 40-yr stands. Fine root biomass and soil microbial biomass was also higher in 70-yr-old stand. Root exclusion decreased soil respiration in 40-yr stand, but not in 70-yr stand. Soil microbial biomass was higher in 70-yr stand, but there was no monthly variation between July and November. The results suggest that soil respiration may increase as plant stand ages and microbial contribution could play more roles in older stands.

• Journal of Bio-Environment Control
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• v.18 no.4
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• pp.413-419
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• 2009

The appropriate dripper position in perlite bag was investigated for tomato production. Drippers were laid at 5(F5), 15cm (F15) away from the stem base or 5cm at first and then moved to 15cm later (M5-15). Roots were developed more near the stem base in F5, while less in F15. Roots were distributed evenly in M5-15. In vertical distribution of water in perlite bag, water content was higher as it went deeper with the variation by dripper positions. Yield was high in F15 and low in F5. In conclusion the position of dripper is the best at 15cm from the stem base in perlite bag culture in view of root distribution and yield.

• Korean Journal of Environmental Biology
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• v.17 no.2
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• pp.153-158
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• 1999

Uptakes of N and P by Phragmites japonica Steudel. are determined in continuous flow tanks as a function of hydraulic retention time (HRT, days) and nutrient concentration (NC). Results show that the uptake was higher at shorter HRT and higher nutrient concentration, and the regression equations were estimated. Mean above ground biomass of Phragmites japonica in the middle reaches of Sagimak stream was 335.92 g/$m^2$, and estimated uptake by this vegetation were 7.31~20.15 NH$_4$-N, 31.15~95.84 NO$_3$-N, and 4.09~11.48 PO$_4$-P mg/$m^2$/day in Sagimak stream, respectively when HRT was 1~5 days. According to this study, it is concluded that Phragmites japonica Steudel. are suitable for water quality improvement of stream through nutrient uptake at short HRT and high concentration.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 1999.11a
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• pp.187-191
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• 1999

식물의 호흡에 영향하는 환경요인은 총 광합성율에 영향하는 모든 요인을 들 수 있으며 뿌리의 호흡에는 근권환경요인 및 질소 흡수량과 같은 영양요인도 들 수 있다. 환경요인의 변화에 따른 식물의 생장 및 수량을 예측하는 식물생장모형의 개발은 식물의 생장이 광합성과 호흡에 의해 좌우되므로 환경요화의 변이에 따른 생육모형개발이 우선적이라 할 수 있다. (중략)

• Korean Journal of Environment and Ecology
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• v.26 no.5
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• pp.780-786
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• 2012

A trenching method was used to determine the contribution of root respiration to soil respiration in Quercus acutissima forest in the vicinity of Gongju, Chungnam Province, Korea. $CO_2$ efflux in soil respiration plot($R_{control}$, $R_c$) and microblal respiration plot($R_{trenched}$, $R_t$) in Q. acutissima forest were measured from June 2011 to May 2012 by using IRGA soil respiration analyzer. Seasonal $CO_2$ efflux in $R_c$ and $R_t$ were higher in summer season than in winter season. In August, maximun $CO_2$ efflux in $R_c$ and $R_t$ was 1.345 and 0.897 g $CO_2\;m^{-2}\;hr^{-1}$, respectively. $CO_2$ efflux in $R_t$ was lower by 33.31% than that in $R_c$(P<0.05). In January, $CO_2$ efflux in $R_c$ and $R_t$ was 0.097 and 0.032g $CO_2\;m^{-2}\;hr^{-1}$, respectively. $CO_2$ efflux in $R_t$ was lower by 67.01% than that in $R_c$(P<0.01). The amount of annual $CO_2$ efflux from $R_c$ and $R_t$ was 4.320, 2.834kg $CO_2\;m^{-2}\;yr^{-1}$, respectively. There was a significant correlations between soil temperatures and soil respiration. Contribution of root respiration to total soil respiration in this Q. acutissima forest was 34.40%.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2002.10a
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• pp.236-237
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• 2002

해초생태계는 해초 잎 및 지하경, 그리고 뿌리등 해초와 직간접적으로 영향을 주고 받을 수 있는 여러 생물들: 조류와 무척추동물, 해초지를 산란장이나 생육장으로 삼고 있는 어류, 그리고, 식물 및 동물 플랑크톤 등으로 구성되어 있다. 이 중 부착조류는 해초생태계 내에서 생산성의 가장 중요한 요소일 뿐만이 아니라, 종 다양성을 증가시키며, 무척추동물의 먹이 공급의 기본적 요소이다 (McRoy and Helfferich, 1977; Coleman and Burkholder, 1995). (중략)

• Korean journal of applied entomology
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• v.43 no.1
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• pp.27-34
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• 2004

This study was conducted to develop optimal control tactics of the northern root-knot nematode, Meloidogyne hapla, using cultural method and biological agents ｛Bacillus thuringiensis (Bt), Paecilomyces lilacinus and plant extract (Huhjunl)｝ in the fields of Codonopsis lanceolata. Germination of C. lanceolata was susceptible to fosthiazate, but not to Bt or a plant extract. In pot assay, the inhibitory effect of two microbial agents, Bt and Paecilomyces lilacinus, on M. hapla were significant, but less than that of fosthiazate. The plant extract also had significantly inhibitory effect on M. hapla. In field assay, treatments of P lilacinus and fosthiazate resulted in maximal yields and qualities of C. lanceolata. The effect of the plant extract on the yields of C. lanceolata was also better than no treatment. The nematode-occurring condition of the fields before transplanting had significant effect on development of C. lanceolata; nematode-occurring field type gave less yields than nematode-free field type. These results suggest that a cultural control technique using paddy field, microbial pesticides using Bt or P lilacinus, and the plant extract are the promising control tactics against M. hapla in C. lanceolata fields. As a field manual to decrease economical damage of C. lanceolata due to M. hapla, this study suggests that C. lanceolata can be cultured directly in paddy field or in upland field after nematode control using microbial agents or the plant extract.

• The Korean Journal of Mycology
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• v.22 no.2
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• pp.160-171
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• 1994

Microscopic observations of arbuscular mycorrhizae (AM) were done with the colonizations of AM and the determinations of chitin in the plant roots of Sorghum bicolor, Cassia mimosoides, Capsicum annuum and Allium fistulosum. The intercellular and intracellular hyphae, arbuscules and vesicles were microscopically observed, according to increases of colonization of AM in the roots of four plants. The growth of AM fungi appeared sigmoid with the cultivation days after inoculation. The growth of AM fungi were inversely influenced by the additions of commercial fertilizers, P

• Journal of Bio-Environment Control
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• v.9 no.3
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• pp.146-150
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• 2000

This study was conducted to investigate the effect of seedling age on quality and yield in bag culture of sweet pepper. Seedlings of 20, 30, 40, 50, and 60 days old were compared. 60 days old seedlings grew faster than 30 or 40 days old seedlings. Mean days to bloom after sowing was fastest as 48 days in 30 days old seedling, followed by 20 days old seedlings. Rot activity was higher in 20 or 30 days old seedlings. Number and length of first lateral roots with thickness of 1.5mm or less, reached to 106.5 and 1.085 cm, respectively in 30 days old seedlings. Root weight, root length, and number of primary lateral roots were the greatest in 30 days old seedling. Greater early yield a obtained in 50 and 60 days old seedling, while late yield was grater in 30 or 40 days old seedlings.

• Journal of Bio-Environment Control
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• v.30 no.4
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• pp.251-256
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• 2021

This study aimed to compare the growth and production of paprika (Capsicum annuum) planted directly on a coir substrate slab according to the bending methods. The existing root direction was bent to 0° (I-type), 90° (L-type), and 180° (U-type), respectively. The weekly average growth such as stem length, diameter, and leaf area tended to be the highest in the I-type bending, but there was no statistical difference. Root weight at 46 weeks after planting was also about 1.3 to 1.7 times heavier in the I-type than the L- and U-type bending. As the yield produced by 330 plants by bending methods, the initial yield was the highest in the U-bending, but then the highest in the I-bending. Accordingly, the total yield was the highest in I-bending. Consequently, when planting on coir substrates directly in paprika cultivation, the I-type bending should be considered most suitable for securing root and plant vigor in the early stages of planting and for enhancing fruiting stability.