• Korean Journal of Soil Science and Fertilizer
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• v.34 no.1
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• pp.8-16
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• 2001

This experiment was conducted to investigate the effects on plant growth, soil chemical properties and microbial flora with microbial fertilizer to chinese cabbage cultivation. The plant growth was promoted and the yield increased by application of Tian Li Bao(TLB) microbial fertilizer as compared with the control. However, yield a littler decreased in case of the reduced amount of urea application as a top dressing and half of compost chicken manure as a basial fertilizer even if treated with TLB microbial fertilizer. Organic matter and total nitrogen contents decreased as compared to those in the control, and total nitrogen ranged in 0.76~1.44% in the treatments at harvesting time, and decreased with application of TLB microbial fertilizer compared to that of the control. The available phosphorus content in the field before experiment was 559ppm, but it was 755ppm and 653 in the control and treatments at harvesting time, respectively. Therefore, it was shown that phosphorus content in the treatment was lower than that of the control. On the other hand, total nitrogen, phosphorous and K ranged from 2.62 to 2.94%, from 1.48 to 1.55% and from 3.60 to 4.38% in plants after harvest, respectively. There were no significant differences among the treatments. For the soil microbial flora, the population of bacteria in the treatments decreased with application of microbial fertilizer as compared with the control over all cultivation periods. It was shown that the population of pseudomonas spp. was over 3 times higher than that of the control after harvesting. The population of actinomycetes didn't show difference among the treatments, but high density of fungi after harvesting were observed in the treatments.

• Korean Journal of Soil Science and Fertilizer
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• v.21 no.4
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• pp.443-449
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• 1988

The effects of rice-straw annual application on nitrogen fixing microbial flora in the soil of paddy fields and their biological activities were investigated. Experiments were performed in both NPK fertilizer applied soil and rice-straw applied soil of Agricultural Station in Aomori-ken, Japan. The following results were obtained. 1. The ARA by phototrophs was significantly increased in both soil plots. From the soil plot in which 300ppm-nitrogen was applied, the increase of ARA began to be seen from three weeks later. On the other hand, 33ppm-nitrogen applied soil plot and non-nitrogen applied soil plot showed the ARA increase from the beginning. The amount of ARA by non-phototrophs was only one-tenth of that by phototrophs. 2. For the first three weeks, the phototrophic bacteria (mainly Rhodopseudomonas) were predominant in both soil plots. Since then, as the ARA rapidly increased, the proliferation of blue-green algae forming heterocysts was remarkably promoted. Such effects were more distinct in the rice-straw annually applied soil plot than in the NPK fertilizer annually applied soil plot. 3. The degree of proliferation of blue-green algae depended on the amount of applied nitrogen. While Anabaena, Nostoc and Cylindrospermum were largely proliferated in the non-nitrogen applied soil plot, Cylindrospermum and Calothrix were in the 33ppm-nitrogen applied soil plot, but Calothrix tended to predominated in the 100ppm-nitrogen applied soil plot.

• Korean Journal of Agricultural Science
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• v.27 no.1
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• pp.1-4
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• 2000

To know the effect of soil treatment with some microbial materials on growth and yield in Korean ginseng, the investigation was undertaken. Significant increases on growth and yield of Korean ginseng plants were achieved by treating soil with microbial materials. Soil treatment with microbial materials resulted in up to 32-68% increment in fresh weight of roots in a 5 month period. The mechanism by which these microbial materials enhance plant growth and root yield may be associated with changes in the composition of rhizosphere microbial flora.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 2000.04a
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• pp.128-134
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• 2000

In the course of flora analysis of soil Archaea, we found very strange 16S rDNA clones, which could possibly constitute a sister clade from known two archael, Crenarchaeota and Euryarchaeota, lineages. Overall signature sequences showed that the clones were closely related to domains Archaea and Eucarya. However, at least nine nucleotides distinguished the novel clones from domains Archaea and Eucarya. Phylogenetic trees drawn by maximum parsimony, neighbor joining and maximum likelihood methods also showed unique phylogenetic position of the clones. A very specific primer set was synthesized to detect the presence of the novel group of organisms in terrestrial environments. A specific DNA fragment was amplified from all of paddy soil DNAs, and this fact suggests that the novel organisms inhabit paddy soils.

• Korean Journal of Soil Science and Fertilizer
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• v.47 no.6
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• pp.451-456
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• 2014

Organic amendment practices can influence diversity and activities of soil microorganisms. There is a need to investigate this impact compared with other types of materials. This study was carried out to evaluate the long term effects of chemical and organic fertilizer on soil microbial community in upland field. During the last 11 years green manure, rice straw compost, rapeseed cake, pig mature compost, NPK, and NPK + pig mature compost were treated in upland soil. Organic fertilizer treatment found with high bacterial colony forming units (CFUs) as compared to chemical and without fertilizer treatment. There was no significant difference in the actinomycetes and fungal population. The average well color development (AWCD) value was the highest in green manure and, the lowest in without fertilizer treatment. Analyses based on the denaturing gradient gel electrophoresis (DGGE) profile showed that rice straw compost and pig mature compost had a similar banding pattern while rapeseed cake, NPK, NPK + pig mature compost and without fertilizer treatment were clustered in another cluster and clearly distinguished from green manure treatment. Bacterial diversity can be highly increased by the application of organic fertilizer while chemical fertilizer had less impact. It can be concluded that green manure had a beneficial impact on soil microbial flora, while, the use of chemical fertilizer could affect the soil bacterial communities adversely.

• Journal of Plant Biotechnology
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• v.34 no.1
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• pp.75-80
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• 2007

The release of genetically modified organisms ($GMO_{s}$) into the environment has the potential risks regarding the possibility of gene transfer from $GMO_{s}$ to natural organisms and this needs to be evaluated. This study was conducted to monitor the possible horizontal gene transfer from herbicide-resistant zoysiagrass (Zoysia japonica Steud.) to indigenous microorganisms. We have first examined the effect of field-released GM zoysiagrass on the microbial flora in the gut of locust (Locusts mlgratoria). The microbial flora was analyzed through determining the 165 rDHA sequences of microorganisms. The comparison of the microbial flora in the gut of locusts that were captured at the field of GM zoysiagrass and of wild-type revealed that there is no noticeable difference between these two groups. This result indicates that the GM zoysiagrass does not have negative impact on microbial flora in the gut of locust. We then investigated whether the horizontal gene transfer occurred from GM zoysiagrass to microbes in soil, rhizosphere and faecal pellets from locusts by utilizing molecular tools such as Southern hybridization and polymerase chain reaction (PCR). When the total DNAs isolated from microbes in GM zoysiagrass and in wild-type zoysiagrass fields were hybridized with probes for bar or hpt gene, no hybridization signal was detected from both field isolates, while the probes were hybridized with DNA from the positive control. Absence of these genes in the FNAs of soil microorganisms as well as microbes in the gut of locust was further confirmed by PCR. Taken together, our data showed that horizontal gene transfer did not occur in this system. These results further indicate that frequencies of transfer of engineered plant DNA to bacteria are likely to be negligible.

• 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($r=0.352^{**}$).

• Korean Journal of Soil Science and Fertilizer
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• v.32 no.1
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• pp.76-83
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• 1999

Studies were conducted during 2 months from May of 1997 to evaluate the effects of pig manure compost(PMC) on soil microbial flora. To do so, a field experiment of Chinese cabbage(Brassica campestris L.) was conducted in a randomized block design on a sandy loam soil and microbial floral characteristics in soils were analyzed. Treatments to control included the application of PMC at (A) $8Mg\;ha^{-1}$CM-8), (B) $29Mg\;ha^{-1}$(CM-2,9), and (C) $57Mg\;ha^{-1}$(CM-57), and of chemical fertilizer(D) at $320N-80P_2O_5-200K_2O\;kg\;ha^{-1}$(NPK). In each treatment, the rhizosphere and non-rhizosphere soils were tested for the analysis of microbial populations. The populations of bacteria, actinomycetes, and fungi increased in soils with the applications of PMC and chemical fertilizer, but that of Bacillus sp. decreased. However, the population of fluorescent Pseudomonas sp. was reduced in NPK plots only. With increasing application rates of PMC, the number of colony forming units(cfu) of bacteria (Pseudomonas sp. and actinomycetes) and fungi increased. in all PMC-treated plots, the population density peaked at early growth stage for bacteria(including Bacillus sp.), at late growth for fluorscent Pseudomonas sp., and at harvest for fungi and actinomycetes. The rhizosphere effect was greatest for fluorscent Pseudomonas sp. As the application rates of PMC increased, Total N, organic matter, available phosphate, and exchangeable -K, -Ca, and -Mg increased compared to control, but soil pH was lowered. In NPK plots, EC was 3.4-fold and exchangeable K was 5-fold higher than control.

• Korean Journal of Organic Agriculture
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• v.32 no.1
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• pp.75-90
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• 2024

Biochar is a solid substance with a high carbon content, as it is made out of biomass pyrolyzed under the condition of limited oxygen. This product has attracted attention as an environment-friendly soil amendment because it contributes to carbon neutrally and has improvement effects on the soil environment. This study conducted an experiment to evaluate soil physiochemical properties and microbial community changes in a melon greenhouse according to the applied amount of biochar to investigate the growth characteristics and yields of melons accordingly. In soil physical properties, an increase in the applied amount of biochar resulted in a decrease in bulk density and an increase in porosity of the soil, improving air permeability. In soil chemical properties, an increase in the applied amount of biochar led to a increasing of pH, organic matter and available phosphate content. In the growth characteristics of melons, there was a growing tendency of plant height, leaf length and leaf width according to the increasing application of biochar until 10,000 kg/ha. Moreover, melon yields also increased as the amount of biochar, 13~16% higher in 10,000 kg/ha biochar application than no treatment. Compared differences among microbial communities in the soil according to the application of biochar and found that plant beneficial bacteria dominated in biochar treatments. This study demonstrated the potential of biochar as an effective soil amendment in melon greenhouse by showing improvements in soil physicochemical properties and microbial communities.

• Journal of the Korea Organic Resources Recycling Association
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• v.24 no.4
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• pp.77-83
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• 2016

The objectives of this study was to investigate the difference between organic-farming and conventional-farming soils relatives to soil chemical properties and microbial flora. Fifteen soil sampling sites were chosen from the certified organic upland farm, considered with its location, crop and application of organic compost types. Soil chemical properties were analyzed by standard methods established by National Institute of Agricultural Sciences, Rural Development Administration. For the soil chemical properties, the values of pH were ranged from 4.5 to 7.3. The values of electrical conductivity (EC) in the sampling sites were below 2 dS/m of convention cultivation soil. For analyzing the microbial flora, the bacillus(16S rDNA) and cladothricosis(18S rDNA) were analyzed by using PCR-DGGE (Denaturing Gradient Gel Electrophoresis) in the soil of 15 sampling sites. Cluster analysis of biodiversity index was performed by using pattern of DGGE. DGGE patterns and clustering analysis of bacterial DNA from soil extracts revealed that the bacterial community was differentiated between less than 5 years and more than 5 years depending on the cultivation history. But there was no consistent tendency between cultivation history and regional trend in the case of molds. Therefore, it would be very effective to analyze bacterial clusters of organically cultivated soils in long - term cultivated soil for more than 5 years.