• Weed & Turfgrass Science
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• v.4 no.2
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• pp.144-150
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• 2015

Silicate fertilizers known to be effective in improving the growth and density of zoysiagrass. Most silicate fertilizers being used in Korea are slag-originated silicate fertilizer, but some water soluble silicate fertilizers are commercially available recently. This study was conducted to know the effect of water soluble silicate fertilizer, on the growth of zoysiagrass and the change of soil chemical properties in Wagner pot and field experiment. Root length, fresh and dry weight of shoots and stolons, the number of shoots and stolons, total of stolons length and the $SiO_2$ content of internal plant were significantly increased by the $SiO_2$ content but chemical properties of the soil were not significantly changed by the $SiO_2$ content. The $SiO_2$ contents of 18 and $36{\mu}lml^{-1}$ did not show significance difference, and therefore a reasonable application the content of $SiO_2$ was thought to be $18{\mu}lml^{-1}$. Foliar spray of water soluble silicate fertilizer is believed to enhance the growth and density of zoysiagrass than soil application.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.6
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• pp.1016-1022
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• 2011

Application of silicate fertilizers is typically practiced with several year's interval to amend soil quality and improve rice productivity at the paddy field in Korea. Most of silicate fertilizers applied in Korea is slag-originated silicate fertilizer. Some water soluble silicate fertilizers are manufactured and commercially available. The objective of this study was to assess changes of soil chemical properties in paddy field by applying slag-originated silicate fertilizer and water soluble silicate fertilizer. Field experiment was conducted on a silt loam paddy soil, where four levels of each silicate fertilizer were applied in soil at the rate of 0, 1, 2, 4 times of the recommended levels. Application of slag-originated silicate fertilizer increased soil pH, while no significant pH increase occurred with the treatment of water soluble silicate fertilizers. Soil pH increased 0.4~0.5 with the 1 time of recommended level of slag-originated silicate fertilizer. Available $SiO_2$ contents also significantly increased with the treatment of slag-originated silicate fertilizer at 15 and 35 days after treatment, while decreased after 60 days after treatment possibly due to rice uptake. Exchangeable Ca, Mg and available phosphate contents in soil increased with application of slag-originated silicate fertilizer, while a little increases for them were shown with the application of soluble silicate fertilizer. $SiO_2$/N ratios in rice straw for 1 time of recommended level of slag-originated silicate fertilizer was 11.5, while that of control was 8.4, which was much lower value. Throughout this study, soil application of slag-originated silicate fertilizer enhanced soil chemical properties, while water soluble silicate fertilizer application in soil needs further study resulting in a little effects on soil property.

• Korean Journal of Poultry Science
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• v.44 no.4
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• pp.267-274
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• 2017

This study was conducted to investigate the effect of feeding with dietary silicate based complex mineral (SCM) on the performance of laying hens. SCM at five levels (0%, 0.2%, 0.4%, 0.6% and 0.8%) was added to commercial diets, and fed to four hundred fifty Hy-Line Brown from fifty four to sixty five weeks of age. Egg production increased as the addition of dietary SCM to basal diets increased up to 0.6% (P<0.05). Furthermore, Feed intake increased in a manner similar to that of egg production (P<0.05). However, there was no difference in feed efficiency among the treatments. Eggshell thickness and breaking strength were significantly higher for the chickens fed with SCM than control from sixty weeks old to the end of experiment (P<0.05). Similarly, albumen height and Haugh unit were significantly higher for the chickens fed with SCM compared to those of control group (P<0.05). AST of birds fed SCM showed significantly higher than control (P<0.05). However, blood neutral fat level tended to increase in SCM treatments. Moreover, bone mineral density increased with SCM addition up to 0.4% (P<0.05). IL-2 (Interleukin-2) and IL-6 (Interleukin-6) levels appeared to be improved in the chickens fed with SCM addition diets, although not statistically different from all treatments. The results of this study indicated that the optimum SCM for improving the performance, egg quality and immunological competence of laying hens from 54 to 65 weeks of age was 0.6%.

• Korean Journal of Soil Science and Fertilizer
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• v.18 no.3
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• pp.282-288
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• 1985

This experiment was conducted to investigate the changing patterns of the available elements by the control of lime addition amount and temperature in Acid Sulfate Soils under the submerged condition. The results obtained were summarized as follows: 1. pH and contents of available phosphate, soluble silicate, $NH_4-N$, and exchangeable iron in soils were decreased but exchangeable aluminium and manganese, and water soluble sulfur in soils increased after submergence. 2. Lime treatment increased pH, available phosphate, soluble silicate, $NH_4-N$, and water soluble sulfur, but that decreased exchangeable aluminium, iron, and manganese in soils. 3. Treatment with 12me/100gr of Ca as $CaCO_3$, showed the marked effect in increasing the exchangeable aluminium and iron, and increasing pH value to about 6.5 as well as available phosphate and $NH_4-N$. 4. Increases in available phosphate, $NH_4-N$, and exchangeable iron with aging of the soil flooded and lime treated were higher at $35^{\circ}C$ than those at $25^{\circ}C$. 5. Throughout submerged period a significant positive correlation was observed between pH and soluble silicate while the pH has negative correlation with exchangeable elements such as aluminium, iron, and manganese etc.

• Journal of the Korean Society for Advanced Composite Structures
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• v.6 no.4
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• pp.8-15
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• 2015

The demand for environmental consideration is on the increase in civil engineering. This study focuses on the development of technology to reduce the use of carbonate cement and improve its performance by using a silicate mineral and hardening agents, and presents the test results for the demonstrative evaluation of the properties of the raw material. Highly active feldspar was used as a binder to augment the bonding of the carbonate cement, and their change in strength was observed after test piece construction with the addition of soluble hardening agent. The uniaxial compression strength of the test piece of the general Portland cement with the addition of 0.5% soluble hardening agent, showed an increase by 33% and that of the test piece of cement with the addition of 70% substituted with feldspar increased by 28%. The strength of viscous soil; classified as soft ground, showed an increase of a maximum of 1.7 times when it was mixed with cement and solidifier depending on the curing period. These tests confirmed that a soluble solidifier is effective for improving the strength of a cement binder and that the highly active feldspar can be used as a binder.

• Korean Journal of Soil Science and Fertilizer
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• v.17 no.3
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• pp.218-223
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• 1984

In order to analyze the effects of percolation rate on the growth and yield of rice plants in paddy soils, pot (1a/2000) experiments were carried out. The soil used was highly concentrated with various salts in the horticulture area under vinyl house cultivation, and Samgang variety of Japanica rice was planted. With the increasing rates of percolation, $SiO_2$ and $Ca^{2+}$ were more leached out from soils than supplied by irrigation while $K^+$ and $NH_4{^+}$ were more supplied to soils than leached out. The root activity in the late growth stage was higher in the percolation pots than in the non-percolation pots. Amounts of nutrient uptake of T-N, $P_2O_5$, $K_2O$ and MgO were increased gradually with the increase of percolation rate, but that of $SiO_2$ was maximum at 10mm per day. The percolation rate of 5~10mm per day was considered to be the optimum condition for obtaining more than 95% of relative yield in rice cultivation.

• Journal of the Mineralogical Society of Korea
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• v.20 no.1 s.51
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• pp.47-60
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• 2007

While sedimentological researches on Western coastal tidal flats of Korea have been much pelformed previously, mineralogical and biogeochemical studies are beginning to be studied. The objectives of this study were to investigate mineralogical characteritics of the inter-tidal flat sediments and to explore phase transformation of iron(oxyhydr)oxides and biomineralization by metal-reducing bacteria enriched from the inter-tidal flat sediments from Muan, Jeollanam-do, Korea. Inter-tidal flat sediment samples were collected in Chungkye-myun and Haeje-myun, Muan-gun, Jeollanam-do. Particle size analyses were performed using the pipette method and sedimentation method. The separates including sand, silt and clay fractions were examined by scanning electron microscopy (SEM) with energy dispersive X-ray (EDX) analysis, transmission electron microscopy (TEM), and X-ray diffiaction (XRD). After enriching the metal-.educing bacteria from the into,-tidal flat sediments, the bacteria were used to study phase transformation of the synthesized iron (oxyhydr)oxides and iron biomineralization using lactate or glucose as the electron donors and Fe(III)-containing iron oxides as the electron accepters. Mineralogical studies showed that the sediments of tidal flats in Chung]rye-myun and Haeje-myun consist of quartz, plagioclase, microcline, biotite, kaolinite and illite. Biogeochemical researches showed that the metal-reducing bacteria enriched from the inter-tidal flat sediments reduced reddish brown akaganeite and mineralized nanometer-sized black magnetite. The bacteria also reduced the reddish brown ferrihydrite into black amorphous phases and reduced the yellowish goethite into greenish with formation of nm-sized phases. These results indicate that microbial Fe(III) reduction may play one of important roles in iron and carbon biogeochemistry as well as iron biomineralization in subsurface environments.