• Applied Biological Chemistry
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• v.49 no.3
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• pp.175-179
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• 2006

This study was carried out to investigate the change of rhizosphere microflora in paddy soils of long-term application of same fertilizer by single cropping. Treatments consisted of no fertilizer, NPK, PK, NK, NP and NPK + compost and the same fertilizer has been applied to the soil of each treatment for thirty five years. Any remarkable difference of the microbial population structure was not detected from the rhizosphere of Hwayeongbyeo and that of Hwasambyeo. However, slight difference of dominant microbial species in the rhizosphere was recognized between different fertilization practice. The bacterial population in the rhizosphere was steadily reduced over time after rice plant setting out, while actinomycetal population was increased over time. The increase of actinomycetal population was the highest in the NPK + compost treatment, suggesting the effect of organic matters in the change of actinomycetal population. As for the aerobic culturable bacterial diversity, Bacillus megaterium, B. mycoides, B. licheniformis and B. subtilis were dominants in genus Bacillus, and Streptomyces spororaveus, S. canus, S. tauricus and S. galbus in genus Streptomyces and genus Micromonospora was another dominant in actinomycetes.

• Korean Journal of Soil Science and Fertilizer
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• v.29 no.3
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• pp.297-302
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• 1996

The effect of application rate of pig or chicken manure on the seasonal change of tomato(Minicarol) rhizosphere microflora was investigated by field experiment were surface soil(16cm) mixed with manures 1 weeks before transplanting. 1. Rhizobacteria population of control plot decreased 5 weeks after transplanting(WAT) than 1 WAT and 1.5~2 times higher colony counting was found in DNB(Diluted nutrient broth medium) than NB(Nutrient broth medium) at 15 WAT. 2. Rhizobacteria population at 1 WAT inereased in NB medium with the application rate of both manures but decreased in DNB with chicken manure. Colony counting in NB of 60 and 120 mg/ha treatment was 100 times higher than that of the control. However, rhizobacteria in DNB at 15 WAT(harvest stage) was much higher than that of NB. 3. Application rate did not affect fungi population 1 WAT in pig manure but decresed in chicken manure. At 15 WAT fungi population was 2 times higher than 1 WAT with chieken manure and highest in 30 mg/ha but with pig manure decreased with rate than the control. 4. Actinomycetes population at 1WAT was not different among pig manure rates and decreased with chicken manure than control. At 15 WAT population increased in all manure rates. especially in 10 mg/ha pig manure and 30 mg/ha chicken manure 4 times that 1 WAT.

• Journal of Ginseng Research
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• v.1 no.1
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• pp.51-58
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• 1976

The phenomenon of sail sickness in the continuous cropping of ginseng is n serious problem for the cultivation practices and is an unelucidated subject scientifically. Present study is concerned mainly with ecochemical search on the cause of soil sickness in the continuous cropping of ginseng and the obtained results are summarized as follows: The humic substances isolated from both cultivated and uneulvidated soils with ginseng were compared with respect to its IR spectra but any difference which may be causative of sail sickness between them was not detected. In contrast, same saponin-like substances extracted from the ginseng cultivate soil in root tone were detected but not from the uncultivated soil. Presumably. the saponin like substances in the soils are originate) from the ginseng radices and are accumulaetd in root zone year by year, while the interrelation between the root exudate of ginseng and soil sickness is still obscure. According to a survey on the distributive Pattern of microflora in rhizosphere of ginseng radices the number of fungi is relatively diminished with the cul tivation years, while the number of actinomycetes is increased. It is supposed that the soil sickness in the continuous cropping of ginseng has any correlation between the activities of microflora in rhizosphere and the reef exudates.

• International Journal of Industrial Entomology and Biomaterials
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• v.5 no.2
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• pp.217-220
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• 2002

Mulberry being a foliage crop is grown extensively for feeding of silkworms and are also used for cattle feeding. These loaves are highly nutritious, which contain various mineral elements and bio-molecules such as carbohydrates, proteins, lipids and other essential amino acids, etc. In the present study, deproteinized mulberry leaf juice was used for preparation of the medium for cultivation of various types of microbes. Results revealed that deproteinized mulberry leaf juice medium is best for isolation of fungi, bacteria and actinomycetes and this medium can be substituted with synthetic media, which are haying the costly ingredients for isolation and identification of bacteria, fungi and actinomycetes. Further, this deproteinized mulberry juice medium can also be used in mass multiplication of useful/beneficial microbes to enhance soil microflora to improve soil fertility and to avoid root diseases. Perspective enterprises can take up the mass multiplication/large-scale production of useful microbes such as Trichoderma, Rhizobium, Pseudomonas and Bacillus to use in mulberry and in other agricultural crops using deproteinized mulberry leaf juice.

• Korean Journal of Organic Agriculture
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• v.13 no.4
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• pp.389-400
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• 2005

This study was conducted to investigate into the ecological environments and the soil microflora of purple-bracted plantain lily (Hosta longipes Matsumura) for wild vgetables. Native soil textures of purple-bracted plantain lily were in the order of sandy loam (SL) > loam (L) > clay loam (CL). pH in soil was relatively acid by 4.8, electric conductivity was 0.08mS/cm, and organic matter content was 0.08g/kg. CEC was measured by $100.8cmol^{(+)}kg^{-1}$ and available phosphate was 103.4mg/kg. Contents of exchangeable cations in terms of potassium, calcium, and magnesium were measured by $0.33cmol^{(+)}kg^{-1},\;2.26cmol^{(+)}kg^{-1},\;and\;0.87cmol^{(+)}kg^{-1}$, etc. Diurnal changes in the air temperature of the natives were 15 to $20^{\circ}C$, that temperature differential was relatively little compared with that in open field by 15 to $30^{\circ}C$. Relative humidity in the natives were much more humid by 60 to 80% compared with that in open feld by 35 to 85%. Light intensity in the natives and the open field at ten o'clock were $2,300{\mu}mol/m^2/sec.\;and\;1,750{\mu}mol/m^2/sec.$ Total number of soil microorganisms were $8.4{\times}10^7\;c.f.u./g$. Mycorrhizal spore densities over $500{\mu}m,\;355{\sim}500{\mu}m,\;251{\sim}354{\mu}m,\;107{\sim}250{\mu}m\;and\;45{\sim}106{\mu}m$ were 0.8, 1.3, 2.1, 38.1, and 110.0 respectively. Mycorrhizal root infections by vesicle and hyphae were 17% and 6%. However, arbuscules in the roots were not shown.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.4
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• pp.622-627
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• 2012

The processes to determine the composition, dynamics, and activity of infection mechanisms by the rhizosphere microflora have attracted the interest of scientists from multiple disciplines although considerable progress of the infection pathways and plant-pathogen interactions by soil borne fungal pathogens have been made. Soilborne pathogens are confined within a three-dimensional matrix of mineral soil particles, pores, organic matter in various stages of decomposition and a biological component. Among the physical and chemical properties of soils soil texture and matric water potential may be the two most important factors that determine spread exudates by soil borne fungal pathogens, based on the size of the soil pores. Pathogenic invasion of plant roots involves complex molecular mechanisms which occur in the diffuse interface between the root and the soil created by root exudates. The initial infection by soilborne pathogens can be caused by enzymes which breakdown cell wall layers to penetrate the plant cell wall for the fungus. However, the fate and mobility of the exudates are less well understood. Therefore, it needs to develop methods to control disease caused by enzymes produced by the soilborne pathogens by verifying many other possible pathways and mechanisms of infection processes occurring in soils.

• Korean Journal of Soil Science and Fertilizer
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• v.31 no.2
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• pp.204-210
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• 1998

The experiment was conducted to obtain the basic data required to characterize and improve rhizosphere environment of salt-accumulated greenhouse(SAG) soils by comparing the soil properties and the microbial flora of such soils to those of unprotected arable upland(UAU) soils. Soils were sampled from greenhouses and unprotected upland fields around the country. Microbial propulation, biomass C content and soil chemical properties were of interest. Population density of fluorescent Pseudomonas was high in UAU soils, while those of pathogenic Fusarium sp. and fluorescent Pseudomonas were low in SAG soils. With increasing soil organic matter(OM) content, the population densities of Bacillus sp., fluorescent Pseudomonas sp., Enterobacteriaceae, and microbial biomass C content increased. As soil electrical conductivity(EC) increased higher than $5.1dS\;m^{-1}$, the ratios of bacteria to fungi(B/F) and actinomycetes to fungi(A/F) and the population density of fluorescent Pseudomonas decreased remarkably. The soil pH was positively related to the population density of aerobic bacteria, while it was negatively related to that of fungi. The soil OM content was significantly correlated to the population densities of actinomycetes($r=0.226^*$). Bacillus sp.($r=0.334^{**}$), Enterobacteriaceae($r=0.276^*$), and the microbial biomass C content($R=0.439^{**}$). The population density of actinomycetes was also significantly correlated with soil exchangeable Ca($r=0.334^{**}$) and Mg($r=0.352^{**}$).