• Korean Journal of Soil Science and Fertilizer
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• v.36 no.4
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• pp.233-238
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• 2003

The effect of phosphate solubilizing microbes (PSM) on plant P uptake and growth in rock phosphate applied soil was tested under a greenhouse condition. Tobacco plants were grown in nonsterilized soil inoculated with Penicillium oxalicum CBPS-3F-Tsa with or without rock phosphate application as P fertilizer. Phosphorus concentration in tobacco plants was increased by the application of rock phosphate, while inoculation of soil with fungi further significantly increased P concentration in tobacco plants compared with the noninoculated treatments. Phosphorus uptake by tobacco plants was also increased by the application of rock phosphate and PSM inoculation, and the significant comparison has been made with single rock phosphate treatment. Growth of tobacco plant was also significantly increased in the treatments receiving rock phosphate, while the combined application of rock phosphate and PSM further increased plant growth. It was concluded that the positive effect of PSM inoculation on plant growth was closely related in plant P content and uptake. These results suggest that Penicillium oxalicum CBPS-3F-Tsa could solubilize insoluble soil phosphates and rock phosphate which can promote growth and P uptake of tobacco plants.

• Current Research on Agriculture and Life Sciences
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• v.31 no.2
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• pp.88-93
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• 2013

The cultivation methods of Acanthopanax in Korea need to be optimized. Hence, this study investigated the effect of different fertilizer ratios and planting dates on the growth and acanthoside D content of two (2) Acanthopanax species. The current recommended fertilizer rate of 10.5-8.5-8.5 $kg/ha^-$ ($N-P_2O_5-K_2O$, respectively) produced the best plant growth of Acanthopanax. For the first year, the acanthoside D content resulting from the 2P (2x phosphate) rate was higher than that from the other fertilizer ratios, yet there were no significant differences resulting from the various treatments for either Acanthopanax divaricatus or Acanthopanax koreanum. Similarly, for the second year, there were no significant differences in the acanthoside D content resulting from the various fertilizer ratios, although for both species the acanthoside D content resulting from the 2P rate was slightly higher than that from the other treatments. Therefore, the results indicated that doubling the amount of phosphate increased the acanthoside D content. Plus, the optimum planting date with respect to growth and productivity for Acanthopanax divaricatus was identified as April 15.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.5
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• pp.817-821
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• 2012

Soil samples collected from abounded mines of Boryeong area in South Korea were used in isolating bacterial strains and their capacity to solubilize inorganic phosphates and heavy metal tolerance were assessed in vitro. Three different inorganic phosphate sources (Ca phosphate, Fe phosphate, and Al phosphate) and four different heavy metals (Co, Cd, Pb and Zn) each with three concentrations ($100{\mu}g\;mL^{-1}$, $200{\mu}g\;mL^{-1}$, and $400{\mu}g\;mL^{-1}$) were used. The bacterial isolates PSB-1, PSB-2, PSB-3, and PSB-4 solubilized significantly higher amount of Ca phosphate during the first five days of incubation though subsequent drop in soluble phosphorus level in the medium was observed at the later stage (after 5 days) of the incubation. Solubilization of Ca phosphate and Fe phosphate was concomitant with the acidification of the culture medium compared to the control where it remained constant. Isolated strains could solubilize Fe phosphate to certain extent ($25-45{\mu}g\;mL^{-1}$) though solubilization of Al phosphate was found negligible. All the isolates were tolerant to heavy metals (Cd, Pb, and Zn) up to the concentration of $400{\mu}g\;mL^{-1}$ except PSB-1 and PSB-8, which were shown to be vulnerable to Co even at $100{\mu}g\;mL^{-1}$. Heavy metal tolerant strains should be further evaluated for plant growth promoting activities also under field conditions in order to assess their agricultural and environmental significance.

• Korean Journal of Soil Science and Fertilizer
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• v.28 no.3
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• pp.278-286
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• 1995

Phosphate-solubilizing microorganisms were isolated from agricultural area in Korea, and the solubilizing potential of microorganisms was evaluated in vitro. Of the several microorganisms Pseudomonas putida, Penicillium sp., and Aspergillus niger showed solubilization in all phosphatic compounds such as hydroxyapatite, tricalcium phosphate, aluminium phosphate and rock phosphate tested. Inorganic P solubilization was directly related to the pH drop by each microorganisms. Aspergillus niger was found to be more active in solubilizing phosphate than Pseudomonas putida and Penicillium sp.. The maximum concentration of phosphorus released from each of aluminium phosphate, hydroxyapatite and tri-calcium phosphate by Aspergillus niger in liquid culture was 776ppm, 665ppm and 593ppm, respectively when $KNO_3$ was added as nitrogen source. For rock phosphate, it was 411ppm with ammonium sulfate as nitrogen source.

• Korean journal of applied entomology
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• v.9 no.1
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• pp.7-13
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• 1970

1. Kum Nam Poong which is highly susceptible to bacterial leaf blight was used as the host plant throughout this experiment. Xanthomonas oryzae 6526 was inoculated on the top of upper leaves by single needle inoculation method. After 14 days, the enlarged spots were examined in the experimental pots. Each of 3 levels of nitrogen, phosphate and potassium pots were arranged at random with three replications. 2. The amounts of nitrogen fertilizer applied and the lesion development of bacterial leaf blight were positively correlated regardless of application of phosphate and potassium fertilizers. 3. The effect of phosphate fertilizer on the lesion development was not significantly different from standard level. The lesion development was stimulated when the amount of phosphate fertilizer was increased as twice as standard level. 4. The inhibitory effect of potassium fertilizer on leaf blight was maximum by applying standard level. The stimulative effect of potassium fertilizer on the lesion development, however, was noticed. when potassium fertilizer applied was increased as twice as the standard level. 5. The heading date and spike number of rice plant were significantly correlated with the lesion development, and such phenomena were depended on the amount of nitrogen fertilizer applied regardless of the other fertilizers applied in this experiment.

• Korean Journal of Soil Science and Fertilizer
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• v.16 no.1
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• pp.56-63
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• 1983

On a newly reclaimed soil, an experiment was carried out for the elucidation of proper rate of phosphorus fertilizer and application method to increase soybean yield in Honam area. 1. The yield was high in whole layer placement of phosphorus fertilizer and low in deep placement. 2. Broadcasting with 15% of phosphate fixation coefficent and whole layer and deep placement of fertilizer with 10% of phosphate fixation coefficent showed maximum yield. 3. Large application of phosphate increased stem diameter and number of blanches and podes. 4. Application of phosphorus fertilizer increased phosphate content in soil from 9 ppm to 48-223 ppm and contents of bases 5. Significant positive correlation was obtained between soybean yield and phosphorus uptake amount.

• Korean Journal of Soil Science and Fertilizer
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• v.42 no.6
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• pp.423-429
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• 2009

Rhodiola rosea L., a traditional medicinal plant in Eastern Asia, is widely used by astronauts, divers and mountaineers to improve their stress resistance. This experiment was conducted to investigate the optimum application rates of phosphate and potassium under the forcing cultivation for high-quality Rhodiola rosea L. production. The application rate of $8kg\; 10a^{-1}$ of phosphate and $30kg\;10a^{-1}$ of potassium showed the highest yield of Rhodiola rosea L. root. There was no significant difference between the application rates of phosphate or potassium fertilizer and the content of salidroside.

• Korean Journal of Soil Science and Fertilizer
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• v.37 no.1
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• pp.36-40
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• 2004

It is now widely accepted that immobilized microbial cells can overcome some of the problems associated with microbial survival stability, efficacy, storage, transportation and ease of application in agricultural environments. Pantoea agglomerans, a phosphate solubilizing bacterium, was immobilized in alginate, agar and gelatin carriers. All the three immobilfized carriers with bacterial cells of P. agglomerans were compared for solubilization of tricalcium phosphate in pure liquid cultures. While alginate beads were tested for phosphate solubilization on alternate days up to five days, agar beads and gelatin cubes were subjected for one time phosphate solubilization analysis after seven days. Both alginate and agar immobilized cells of P. agglomerans exhibited higher efficiency in increasing the solubilizaliun of tricalcium phosphate than gelatin immobilized cells. The culture filtrate of alginate bead inoculation treatment registered a rapid increase in soluble phosphate concentration upon incubation. A corresponding decrease in the pH of the medium was also observed in all the treatments.

• Journal of Radiation Protection and Research
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• v.42 no.1
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• pp.33-41
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• 2017

Background: Phosphate rock and its by-product are widely used in various industries to produce phosphoric acid, gypsum, gypsum board, and fertilizer. Owing to its high level of natural radioactive nuclides (e.g., $^{238}U$ and $^{226}Ra$), the radiological safety of workers who work with phosphate rock should be systematically managed. In this study, $^{238}U$, $^{232}Th$, $^{226}Ra$, and $^{40}K$ levels were measured to analyze the transport characteristics of these radionuclides in the production cycle of phosphate rock. Materials and Methods: Energy dispersive X-ray fluorescence and gamma spectrometry were used to determine the activity of $^{238}U$, $^{232}Th$, $^{226}Ra$, and $^{40}K$. To evaluate the extent of secular disequilibrium, the analytical results were compared using statistical methods. Finally, the distribution of radioactivity across different stages of the phosphate rock production cycle was evaluated. Results and Discussion: The concentration ratios of $^{226}Ra$ and $^{238}U$ in phosphate rock were close to 1.0, while those found in gypsum and fertilizer were extremely different, reflecting disequilibrium after the chemical reaction process. The nuclide with the highest activity level in the production cycle of phosphate rock was $^{40}K$, and the median $^{40}K$ activity was $8.972Bq{\cdot}g^{-1}$ and $1.496Bq{\cdot}g^{-1}$, respectively. For the $^{238}U$ series, the activity of $^{238}U$ and $^{226}Ra$ was greatest in phosphate rock, and the distribution of activity values clearly showed the transport characteristics of the radionuclides, both for the byproducts of the decay sequences and for their final products. Conclusion: Although the activity of $^{40}K$ in k-related fertilizer was relatively high, it made a relatively low contribution to the total radiological effect. However, the activity levels of $^{226}Ra$ and $^{238}U$ in phosphate rock were found to be relatively high, near the upper end of the acceptable limits. Therefore, it is necessary to systematically manage the radiological safety of workers engaged in phosphate rock processing.

• Journal of Animal Environmental Science
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• v.3 no.1
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• pp.35-42
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• 1997

The purpose of this study is to investigate the effect of the biologically treated animal wastewater as a liquid fertilizer in the paddy rice. The treated water has content of the ammonia nitrogen 24mg/I and nitrate 40 mg/I on an average in the first year. A trace of nitrite has been shown. The phosphate content was 92 mg/I on an average. The amount of yielded rice was 365kg/10a for test 1 (no fertilizer), 388dg/10a for test 2(chemical fertilizer), 526kg/10a for test 3 (treated water) respectively. The treated water showed 35% more in production than the chemical fertilizer. The treated water has content of the ammonia nitrogen 40mg/I and nitrate 67mg/I on an average in the second year. A trace of nitrite has been shown. The phosphate content was 57mg/I on an average. The amount of yielded rice was 402kg/10a for test 1, 505kg/10a for test 2, 607kg/10a for test 3 respectively. Yield of unhulled rice was 20% more in the plot of treated water than that of chemical fertilizer.