• Korean Journal of Soil Science and Fertilizer
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• v.36 no.5
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• pp.290-303
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• 2003

Modern agriculture has been heavily dependent on chemical fertilizers to meet the food demands of ever increasing population. Progressive depletion of major plant nutrients in soil due to intensive cultivation practices has also necessitated the use of higher dose of chemical fertilizers particularly in soils where the organic matter content is very low. Indiscriminate use of chemical fertilizers and pressure on agriculturists to enhance per area crop yields has led to fast depletion of fossil fuel resources with concomitant increase in the prices of chemical fertilizers and also led to environmental pollution. Hence, the current trend throughout the world is to explore the possibility of using alternate nutrient sources or increasing the efficiency of chemical fertilizers by supplementing them with organic fertilizers and bioinoculants comprising largely microbes like, bacteria, fungi, algae etc to enhance nitrogen and phosphates in the soil thus creating a sustainable agricultural environment. Among the different microbial inoculants or biofertilizers, Azospirillum could be a potential candidate due to its non specific host root colonization. It had the capability to fix $N_2$ in wide pH regimes and even in presence of combined nitrogen. Azospirillum inoculation can increase the crop yield to 10-25% and substitute 25% of recommended doses of nitrogenous fertilizers. Apart from nitrogen fixation, Azospirillum is also involved in the root improvement, the activity which was attributed to an increase in the rate of water and mineral uptake by roots. The ability of Azospirillum to produce phytohormones was reported to enhance the root respiration rate, metabolism and root proliferation. They have also been reported to produce polyhydroxybutyrate, that can be used as a biodegradable thermosplastic. A lot of studies have addressed improvements in enhancing its efficiency to fix nitrogen fixation and hormone production.

• Korean Journal of Organic Agriculture
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• v.7 no.1
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• pp.35-48
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• 1998

The total amount of dry matter for the green manure crops was great wheat> rye> barley> Italian ryegrass in that order. The green manure crope were verified to have the reducing effect of injury of successive croppingin peper, mainly reducing the occurance of the most important pepper disease, Phytophthora capsisi, and enhancing the pepper quality in the fruit length and diameter. The direct seeding using current commercial pepper variety was proved as not economical one. In the first year of compost application, the growth and yield of red pepper were rather somewhat decreasing compared with those of check plot applied with organic fertilizers. compst application increased the content of organic matter in soil, which suggested compost could be applied for the sustainable purposes. In preference analysis about taking the new technique, the smaller farmer's cultivation area the more they wanted to accept the LISA farming, compared with the conventional one, could be possible to save 12% in the inorganic fertilizer expenses but wasted 412% ant 163% in both organic fertilizer and operator labor expenses, respectively. At the same time, the LISA decreased 15% in production cost but increased 225% and 139% in organic fertilizer quantity and operator labor hours. Since there was a great deal of difference in technological and economic factors from two farming methods, LISA multi-goal decision modeling is further required.

• Horticultural Science & Technology
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• v.34 no.3
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• pp.414-423
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• 2016

Growers in plug seedling production think that root media in which rockwool is a component has given rise to several environmental problems. Therefore, the demand for new materials as a substitute for rockwool has been increased. This study examined the possibility of cultivation of tomato plug seedlings using a newly developed growing medium with phenolic foam. Plug seeds of tomato cultivar 'Madison' were sown in four pellet-type growing media: Grodan rockwool (GRW), UR rockwool (URW), phenolic foam LC (LC) or phenolic foam LC-lite (LC-lite). Then, the seedlings were transplanted to the four cube-type growing media 19 days after sowing. Seeds were germinated in a growth chamber ($25{\pm}2^{\circ}C$, 80% relative humidity, and dark) for 4 days and then the seedlings were grown with a nutrient solution supplied by an overhead irrigation system in a greenhouse. Plant height, number of leaves, leaf area, and fresh or dry weight of tomato seedlings were the greatest for the seedlings transplanted to URW cube media after being grown on LC-lite pellets. Root grade was the greatest for the seedlings transplanted on LC or LC-lite cube media after being grown on LC pellets. Chemical properties of all media tested for tomato growth were maintained within a stable range, while physical properties of URW showed high values in container capacity, air space, and total porosity. These results demonstrated that the phenolic foam media were effective for seedling growth and can substitute for rockwool as a root medium.

• Current Research on Agriculture and Life Sciences
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• v.16
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• pp.55-63
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• 1998

This experiment was conducted to know tolerance to cold temperature of the grape shoots collected at different locations and dormant periods in 1996 to 1997. The results from this experiment were as follows; (1) There is a little difference among locations in their electric conductance of Campbell Early cultivar, in Dec. 1996. But the least damage was shown at Kyung Joo while severe at Young Dong district in Jan. 1997. (2) Electric conductance of Sheridan cultivar was showing the same tendency as Campbell Early. (3) Early dormant period(December) affected severe bud browning at Young Dong than that of January. The grape shoot collected at Kyung San and Kyung Joo Showed a little influence on bud browning during December and January. (4) Likewise, bark browning of the grape shoot collected at Young Dong showed the same tendency with bud browning test. (5) The bud of grape shoot was bursted even at $-20^{\circ}C$. But rate of bud bursting was lower at Young Dong than the other districts at $-15^{\circ}C$ and $-20^{\circ}C$. From these results, the authors believe that we must introduce and test for suitable cultivation area and temperature before selection of permanent cultivating location.

• Journal of agriculture & life science
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• v.43 no.2
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• pp.47-53
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• 2009

This research is intended to study the induction net of chrysanthemum used in its greenhouse and requiring lots of time for manual work and review the structural safety of a bed and existing greenhouses after designing the bed of a net which increases cropping period by sharply reducing the time of work and provides the bed of induction nets for cultivating chrysanthemum with its existing and new greenhouse. The review of sectional and biodynamic properties in 15 kinds of materials has revealed that the pipes of ${\phi}38.1{\times}1.7t$and ${\phi}38.1{\times}2.0t$ didn't exceed stress ratio but did 10mm drooping allowance. For this reason, the pipe of ${\phi}48.1{\times}1.5t$ net both stress ratio and drooping allowance. For the safety, the middle chamber should be designed into Truss type owing to bed load, wind load, and snow load when the bed of an induction net is installed in the middle chamber. When installing the middle chamber with a truss type, the greenhouse of chrysanthemum in Geochang area needs proper reinforcements because the stress in colullllls and wind proof walls exceeds stress allowance regardless of the installation of a bed.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2019.10a
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• pp.83-83
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• 2019

본 연구는 고품질 산양삼 생산을 위한 표준재배기술 개발을 위해 산양삼의 생육특성과 재배지의 입지환경 간의 상관관계를 구명하고자 하였다. 전국 9지역의 산양삼 재배지를 선정하여 13년생 산양삼의 생육특성을 조사하고, 각 재배지의 임상 및 토양 이화학성을 분석하여 입지환경과 산양삼 생육특성과의 상관관계를 확인하였다. 총 9개의 재배지 중에서 산양삼의 생육특성은 거창과 함양 재배지에서 다른 재배지에 비해 유의적으로 높은 것으로 나타났다. 임산과의 상관관계를 확인한 결과, 산양삼의 부피는 재배지 임상의 흉고직경과 유의적인 정의 상관관계를 보였고, 활엽수의 비율과 유의적인 부의 상관관계, 침엽수의 비율과는 유의적인 정의 상관관계를 보였다. 침엽수의 비율이 100%로 확인된 영월 재배지의 산양삼 생육특성이 다른 재배지에 비해 유의적으로 높지 않은 것으로 확인되어, 이러한 결과는 침활혼효림에서 침엽수의 비율과 상관관계가 있는 것으로 판단된다. 토양 특성과의 상관관계 분석에서는 재배지 토양의 pH, K, Ca, Mg과 생육특성 간의 유의적인 부의 상관관계를 확인할 수 있었다. 이와 같이 산양삼의 생육특성과 입지환경 간의 상관관계를 분석한 결과, 산양삼의 생육은 재배지 임상의 흉고직경이 크고, 침활혼효림에서 침엽수의 비율이 높으며, 토양의 pH, K, Ca, Mg 함량이 높지 않은 재배지에서 적합하다는 것을 확인할 수 있었다. 본 연구의 결과를 통해 산양삼 재배에 적합한 재배적지의 입지환경 조건을 확인할 수 있었고, 산양삼은 7~20년 동안 무농약, 무비료의 청정환경에서 생산하는 것이 원칙이기 때문에 본 연구의 결과를 활용하여 향후 산양삼의 예상재배지를 선정하는데 있어 도움을 줄 수 있을 것으로 사료된다.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2019.10a
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• pp.84-84
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• 2019

본 연구는 전국 임의의 산양삼 재배지를 선정하여 재배지 내의 토양 특성 및 토양세균군집을 분석하고, 토양 특성, 세균군집 및 산양삼 생육특성 간의 상관관계를 구명하기 위하여 수행되었다. 토양 이화학성 분석은 농촌진흥청의 종합분석실 매뉴얼에 따라 분석하였고, 토양세균군집 분석은 pyrosequencing analysis (Illumina platform)를 이용하였다. 토양세균군집과 생육특성 간의 상관관계는 Spearman's rank correlation을 이용하여 분석하였다. 전국 8개 산양삼 재배지로부터 분리한 토양세균군집은 2개의 cluster로 군집화를 이루는 것을 확인하였다. 모든 토양 샘플에서 Proteobacteria와 Alphaproteobacteria가 각각 평균 상대적 빈도수가 35.4%, 24.4%로 우점종으로 나타났다. 나타났다. 두 개의 cluster 간 토양세균군집의 상대적 빈도수를 비교 분석한 결과, 먼저 Proteobacteria (p = 0.03), Actinobacteria (p = 0.02), Ahlpaproteobacteria (p = 0.029), Betaproteobacteria (p = 0.021)는 cluster 1에서 cluster 2에 비해 상대적 빈도수가 유의적으로 높았고, Fimicutes (p = 0.004), Cyanobacteria (p = 0.004), Acidobacteriia (p = 0.041), Ktedonobacteria (p = 0.019), Gammaproteobacteria (p = 0.034), Bacilli (p = 0.009)은 cluster 2에서 유의적으로 상대적 빈도수가 높은 것으로 나타났다. 토양세균군집 cluster 간 산양삼의 생육특성을 비교 분석한 결과, cluster 2 재배지에서 수집한 산양삼 시료의 지하부 생중량은 cluster 1 재배지에서 수집한 산양삼 시료에 비해 cluster 2에서 유의적 (p = 0.04)으로 높았다. 산양삼 생육특성과 토양세균군집 간의 상관관계를 분석한 결과, 산양삼의 생육은 토양 pH가 낮고 Acidobacteria의 상대적 빈도수가 높은 토양에서 증가하였으며, Acidobacteriia와 Koribacteraceae의 상대적 빈도수는 산양삼의 생육과 유의적인 정의 상관관계를 보이는 것으로 나타났다. 본 연구 결과는 토양미생물군집과 산양삼 생육 간의 상관관계를 구명하는 중요한 자료가 될 것으로 생각되고, 나아가 산양삼 재배적지를 선정하는데 있어 보다 명확한 정보를 제공할 수 있을 것으로 사료된다.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.5
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• pp.696-701
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• 2011

This study was conducted to investigate impacts of soil properties on microbial distribution in Jeonbuk orchard fields. Soil samples were collected from 110 sites cultivated with different fruit plants. The population of aerobic bacteria and fungi and the content of soil microbial biomass carbon (C) were found to increase with increasing silt content in the soils. Different activity of dehydrogenase was not observed among the different textures of soil. Microbial distribution, amount of microbial biomass C, and dehydrogenase activity in the soils were not significantly different among the topographic sites. However, in pear and grape fruit plant fields, coliform group of bacteria was found in relatively higher population, $133.0{\times}10^3\;CFU\;g^{-1}$ and $107.4{\times}10^3\;CFU\;g^{-1}$, respectively. Microbial groups were simplified and their density was reduced with increasing the cultivation periods of fruit plants. The soil microbial distribution was proportionally correlated with some of soil properties such as soil pH, soil organic matter (SOM) content, and exchangeable Mg content; in particular, the population of Bacillus sp. was proportionally correlated with soil pH and exchangeable Mg content. The amounts of microbial biomass C and the dehydrogenase activity in the soils were significantly correlated with the contents of SOM and exchangeable Ca ion (p<0.01).

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.6
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• pp.1137-1143
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• 2011

Optimum soil management of chestnut orchards is important to ensure high quality and yields of chestnut. This study was conducted to evaluate soil and green leaf characteristics by establishment periods of chestnut (Castanea crenata Sieb. et. Zucc.) orchards in Sancheong-gun, Gyeongsangnam-do. Total 30 plots with the criteria of similar cultivation practices were chosen and classified into two establishment periods by over 20-year-old orchards (17 plots) and below 19-year-old orchards (13 plots). Soil bulk density was significantly higher (p<0.05) in over 20-year-old ($1.16g\;cm^{-3}$) than in below 19-year-old ($1.03g\;cm^{-3}$) plots. Soils in over 20-year-old plots were severely acidified with pH 4.56 compared to pH 4.73 in below 19-year-old plots. However, soil organic matter, total nitrogen, available phosphorus, and potassium were not significantly different (p>0.05) between both establishment periods. Leaf area, leaf mass, and nutrient (N, P, K, Ca, Mg) concentration of green leaves were also not significantly different (p>0.05) between both establishment periods. The results indicate that soil bulk density in chestnut orchards is dependent on the establishment periods, while soil chemical property and leaf nutrient concentration may be little influenced by the establishment periods.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.6
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• pp.864-871
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• 2010

At the current situation of continuous utilization of heavy metal contaminated upland for agricultural purpose in Korea, minimizing transport of heavy metals from soil to crops is important for securing safety of human health. The present study (in field scale) examined the efficiency of several soil amendments (dolomite, steel slag, lime, zeolite, and compost) on reduction of phytoavailable heavy metals (Cd, Cu, Pb, and Zn) in soil through comparison with no amendment treatment and clean soil cover treatment. For determination of the phytoavailability, 1 M $NH_4NO_3$ extraction and red pepper cultivation were introduced. Among the amendments, in general, dolomite and steel slag were the most effective in reduction of metal (Cd, Pb, and Zn) phytoavailability resulting in less accumulation of these metals in shoot and fruit of red pepper. However, dolomite and steel slag treatment was not as effective as clean soil cover treatment which showed the least metal accumulation in red pepper fruit. Nevertheless, with taking into account the cost, treatment of dolomite or steel slag can be competitive method because the current study showed that dolomite or steel slag treatment reduced accumulated heavy metal concentration effectively in both shoot and fruit of red pepper compared to those from control soil and the concentration in fruit was within the standard value (<0.2 mg $kg^{-1}$ for both Cd and Pb).