• Korean Journal of Plant Resources
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• v.21 no.3
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• pp.230-235
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• 2008

The aquatic fern Azolla spp. is of value as a bio-fertilizer for wetland paddy. It is popular and cultivated widely in other countries like China, Vietnam, and the Philippines, but has yet to be taken up in Korea, in a big way. It fixes nitrogen as high as 3-5kg N per day, because it contains nitrogen fixing blue-green algae, Anabaena azollae. Azolla's ability to create a light-proof mat that suppresses other weeds has been used for centuries in rice production. Azolla spp. has also the capacity to take up the heavy metals such as Mercury and Chromium (75${\sim}$100%) and may be used as a bioaccumulator in the phytoremediation. Azolla meal also can be used as an unconventional feed resource has a potential as a feedstuff for livestock.

• Korean Journal of Medicinal Crop Science
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• v.15 no.3
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• pp.148-151
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• 2007

This experiment was carried out to investigate the effect of several organic fertilizers on the growth and root yield of Liriope platyphylla was planted 30 cm ${\time}$ 10 cm in field from 1998 to 1999. Six treatments of organic fertilizers applied : N.P.K, NPKC (N,P,K+Compost), NPKCO (N.P.K+Compost+Oilcake),NPKCOF (N.P.K+Compost+Oilcake+Fowldropping), NPKCOFP (N.P.K+Compost+ Oilcake+Fowldropping+plant ash), CO (Compost+Oilcake), COF (Compost+Oilcake+fowldropping). Organic matter, available phosphate, and MgO are NaO of soil increased in all of plots with the addition of organic fertilizers. The leaf length, number of leaves and of tillers were increased by the use of organic fertilizers compared to N.P.K fertilizers compared with N.P.K fertilization. The number of tubers were increased by using the organic fertilization N.P.K fertilization and showed higher in the soil depth of 0${\sim}$20 cm. The dry root yield was showed higher in organic fertilizers than in N.P.K fertilizer and highest dry root yield resulted from NPKOF 39% and NPKCOFP 49%.

• Journal of agriculture & life science
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• v.51 no.4
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• pp.139-147
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• 2017

This study was carried out in order to reduce the amount of sawdust for recycling the generated manure from livestock farms, and to investigate the effects on the reducing usage of sawdust and quality of produced compost. To do this, a cylindrical horizontal composting device were used in the experiments and compost was analyzed for judging produce compost quality. The experiment was carried out separately under different cases of operational control conditions. The first case was produced by using sawdust and pig manure mixture(Test-1); the second case was produced by using sawdust, pig manure and the previously produced compost(Test-2). In the second case, Except for some heavy metal content, The water content and C/N ratio were found to be suitable for fertilizer process specification of the RDA(Rural Development Administration) and it was found to reduce the sawdust 1.25tons usage.

• Korean Journal of Soil Science and Fertilizer
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• v.39 no.4
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• pp.185-194
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• 2006

A fungal strain of Trichoderma having strong chitinolytic activity was isolated from field soil enriched with crabshell for several years. Based on 5.8S rRNA, partial 18S, 28S rRNA genes, ITS1, ITS2 sequence analysis and morphological characteristics, the fungus was identified as Trichoderma asperellum and named as Trichoderma asperellum T-5 (TaT-5). The fungus released lytic enzymes such as chitinase and ${\beta}$-1, 3-glucanse, and produced six antifungal substances in chitin broth medium. To demonstrate the protective effect of TaT-5 against damping-off in cucumber plant caused by Rhizoctonia solani, TaT-5 culture broth (TA), chitin medium (CM) and distilled water (DW) were applied to each pot at 10 days after sowing, respectively. Then, the homogenized hyphae of R. solani were infected to each pot at 1 week after TaT-5 inoculation. During experimental period, fresh weight of shoot and root in cucumber plant more increased at TA treatment compared to other treatments. PR-proteins (${\beta}$-1, 3-glucanase and chitinase) activities in cucumber leaves markedly increased at CM and DW treatments, but the activity slightly increased and then decreased at TA treatment at 3 days after infection of R. solani. The activity of PR-proteins activities in cucumber roots at all treatments decreased with time where the degree of decrement was more alleviated at TA treatment than CM and DW. These results suggest that the lytic enzymes (chitinase and ${\beta}$-1, 3-glucanse) and antifungal substances produced by TaT-5 can reduce the pathogenic attack by R. solani in cucumber plants.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.2
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• pp.271-277
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• 2011

To improve the quality of water from water supply source and to establish the management plan of dead plants in flood control reservoir around Juam Lake, the effect of water quality by dead plant in column with passing time was investigated. In column test, the amounts of release by Carex dimorpholepis were $7,893-7,917mg\;m^{-2}\;month^{-1}$ COD, $2,711-2,816mg\;m^{-2}\;month^{-1}$ T-N and $342-547mg\;m^{-2}\;month^{-1}$ T-P. The amounts of release by Miscanthus sacchariflorus were $6,487-6,507mg\;m^{-2}$ COD, $1,813-1,868mg\;m^{-2}$ T-N and $226-405mg\;m^{-2}\;month^{-1}$ T-P in column. Therefore, the release of COD, T-N and T-P by Carex dimorpholepis were more than those by Miscanthus sacchariflorus Benth in column.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.5
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• pp.929-936
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• 2011

To treat non-point source pollution in Dongbok lake, removal efficiencies of pollutants were investigated in Dongbokcheon constructed wetlands (CWs) at different treatment time and wastewater loading. The wetlands consisted of forebay, wetlands ($1^{st}$, $2^{nd}$, $3^{rd}$, $4^{th}$, $5^{th}$, $6^{th}$, $7^{th}$, and $8^{th}$ wetlands) and sedimentation pond. The concentrations of BOD, SS, T-N, and T-P in inflow ranged $0.85{\sim}3.14mg\;L^{-1}$, $3.33{\sim}9.70mg\;L^{-1}$, $0.64{\sim}5.33mg\;L^{-1}$, and $0.03{\sim}0.10mg\;L^{-1}$ from April to October in 2008, respectively. The removal rates of BOD, SS, T-N, and T-P in Dongbokcheon CWs were 34%, 5%, 31%, and 13%, respectively. The removal rates of BOD and T-N were higher than those for SS and T-P. The amounts of pollutant removal in Dongbokcheon CWs were higher in the order of forebay > wetlands > sedimentation pond for BOD, sedimentation pond > wetlands > forebay for SS, sedimentation pond > forebay > wetlands for T-N. The amount of T-P removal in wetlands was higher than forebay and sedimentation pond.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.5
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• pp.709-716
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• 2011

In order to collect basic data of soil environment in the Vicinity of King Sejong Station, King George Island, Antarctica, the physico-chemical characteristics of soils were investigated. Soil samples were collected in Barton Peninsula from 13 sites according to direction from the Sejong Cape. Soils from 13 sites were divided into three groups. The sand percentage of soils were much higher as above 90% than silt and clay percentages of soils at the all sites. Soil texture was classified sandy (10 sites) and loamy sand (3 sites). In distribution characteristics at different soil particles according to direction, large particles ($>500{\mu}m$) were higher in the order of Group 1 (Marian cove coast regions) > Group 2 (Inland regions) > Group 3 (Maxwell bay coast regions). On the other hand, small particles ($<355{\mu}m$) were higher in the order of Group 3 > Group 2 > Group 1. Chemical characteristic of soils showed significant differences at different areas. pH ranged 4.5-6.7, showing it was slightly acid and EC ranged $0.06-0.16dS\;m^{-1}$. T-N, OM and T-C contents were high at #6, #8, #12 and #13 sites. T-P and P2O5 contents were high at #9 and #12 sites. The results of this study will be helpful to understand soil environment in the Antarctic Peninsula and surrounding islands.

• Journal of Bio-Environment Control
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• v.19 no.2
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• pp.97-108
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• 2010

The present study was conducted to investigate photosynthetic responses (Pn), chlorophyll fluorescence (Pe), chlorophyll contents of Allium victorialis var. platyphyllum, Ligularia fischeri, and Ligularia stenocephala growing at four different fertilizing schemes (non-fertilizing and 2.5 $g{\cdot}l^{-1}$, 5 $g{\cdot}l^{-1}$, 10 $g{\cdot}l^{-1}$ fertilizing). Three wild vegetables showed outstanding Pn and Pe at 5 $g{\cdot}l^{-1}$ fertilizing treatment. 10 $g{\cdot}l^{-1}$ of fertilizer, however, proved to be too much eventually leading to declined growth. A. victorialis var. platyphyllum showed good Pn and Pe under shade treatment whereas Pn and Pe of L. fischeri, and L. stenocephala showed the opposite tendency. The chlorophyll contents of the three wild vegetables showed the highest measurement ranging between 11.70~24.36 $mg{\cdot}g^{-1}$ when treated with 5 $g{\cdot}l^{-1}$ of fertilizer. Also it was showed that there were more chlorophyll contents under shade treatment as opposed to full sun. These results showed that 5 $g{\cdot}l^{-1}$ fertilizing treatment is optimal fertilizing of three wild vegetables and fertilizing and light intensity controlling is very important for productivity of vegetables.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.5
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• pp.764-771
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• 2012

In order to develop constructed wetlands for treating hydroponic wastewater in greenhouse, actual constructed wetlands were used the obtained optimum condition in previous study, and the removal rate of pollutant in the water according to 4 kinds connection method of piping such as system A (UP-UP stream), system B (UP-DOWN system), system C (DOWN-UP stream) and system D (DOWN-DOWN stream) were investigated. Removal rate of biochemical oxygen demand (BOD), chemical oxygen demand (COD), suspended solids (SS), total nitrogen (T-N) and total phosphorus (T-P) by system A (UP-UP stream) connection method in actual constructed wetlands were slightly higher than other systems. At the system A, the removal rate of BOD, COD, SS, T-N and T-P were 88, 77, 94, 54 and 94%, respectively. Under different hydroponic wastewater loading, the removal rates of pollutants were higher in the order of $75L\;m^{-2}day^{-1}{\fallingdotseq}150L\;m^{-2}day^{-1}$ $$\geq_-$$ $300L\;m^{-2}day^{-1}$. Therefore, optimum connection method was system A for treating hydroponic wastewater in greenhouse.

• Journal of Bio-Environment Control
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• v.16 no.4
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• pp.358-364
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• 2007

This study was carried out to investigate the effect of phosphorus concentrations in fertilizer solution on growth and development of nutrient deficiency in leaf perilla (Perilla frutesens). The nutrient concentrations in above ground plant tissue, petiole sap and soil solution of root media were also determined. Phosphorus deficiency resulted in a slow growth, lustreless leaves, suffused purple tining in older leaves and falling prematurely. Elevation of P concentrations in fertilizer solution increased the crop growth at 75 days after transplanting. The fresh weight in 0, 0.5 and 4.0 mM treatments were 0.48 g, 9.28 g, and 25.5 g, respectively, and dry weights were 0.06 g, 1.46 g and 4.13 g, respectively. The P concentrations in above ground plant tissue and petiole sap in 4.0 mM treatment were 1.78% and $2.040mg{\cdot}kg^{-1}$, respectively, at 75 days after transplanting. The soil P concentration in 4.0 mM treatment was $1.26mg{\cdot}kg^{-1}$ when it was determined by the 1:2 (sample:water) method. These results indicated that P concentrations higher than 0.3% in above ground plant tissue, $900mg{\cdot}kg^{-1}$ in petiole sap, and $0.57mg{\cdot}kg^{-1}$ in soil solution should be maintained to ensure proper growth of leaf perilla (Perilla frutesens).