• Korean Journal of Soil Science and Fertilizer
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• v.19 no.1
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• pp.9-13
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• 1986

An experiment on strawberry (Fragaria Grandflora EHRH) was conducted in order to compare the effect of two compound fertilizers made for this crop, by Kyonggi Chemical Crop. LTD. with that of muriate of potash, sulfate of potash and ammonium nitrate in a farmer's vinylhouse during the winter period of 1984 to 1985. Results obtained are as follows; 1. The effect of compound fertilizers on the growth, number of inflorescences and yield of strawberry showed no significant difference from the effect of muriate of potash, sulfate of potash and ammonium nitrate. But the former increased the content of reduced, and total sugars soluble in diluted acid in the juice of strawberry. 2. As a whole, sulfate of potash increased sugar content in strawberry juice more than muriate of potash, which became the reason to increase the sugar content in the strawberry juice harvested from the compound fertilizer plots.

• Korean Journal of Soil Science and Fertilizer
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• v.3 no.1
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• pp.11-16
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• 1970

In application of manganese and silica to Akiochi soil, growth of rice plant with potassium was remarkably increased, but the growth without potassium was stunted and the number of the tiller was relatively reduced in comparison with that receiving potassium. The minus potassium plant developed tiny brown spots on the leaves and color of the leaves was dark green. They had smaller leaves and shorter stem while heading advanced. Roots with potassium were long and thick, and new ones developed, while roots without K were very poor, the branch and hair roots very thin, and severe root rot was observed. With minus potassium treatment, the root rot of Jin Heung(commercial variety) was more severe than Nonglim 6(Akiochi resistant). Growth of plant without potassium was very poor, and potassium content of the plant was very low, while nitrogen, phosphorus, silica, iron and manganese contents were higher than potassium supplied plant. Application of $Mn+SiO_2$ to Akiochi soil lowered iron content of plant, and iron content of the plant were also reduced by application of potassium. From the results obtained it can be concluded that root damage of minus potassium plant grown in Akiochi soil supplied $Mn+SiO_2$ was caused by potassium deficiency. Potassium, and $Mn+SiO_2$ applications lowered iron content in the plant grown on Akiochi soil.

• Korean Journal of Soil Science and Fertilizer
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• v.4 no.2
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• pp.161-166
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• 1971

1. Increment of applied $SiO_2$, N and K effected Significantly the rice yield in Akiochi soil. Nitrogen fertilizer, however, should be split in several times. 2. The applied silica accelerated the nitrogen efficiency in particular when the increased nitrogen fertilizer was applied. 3. The number of hill per plant was increased by increasing nitrogen application, while percent of maturity was decreased. But application of increased Potassium gave remarkerbly high percentage of maturity. 4. Application of silica to the Akiochi soil increased both the number of spikelets and percentage of maturity of rice. 5. The increased application of nitrogen raised nitrogen content in plant but decreased the content of silica and potassium. The ratio of $SiO_2/N$ and $K_2O/N$, therefore, decreased. 6. From the results it can be concluded that application of increased nitrogen to the Akiochi soil should be accompanied by application of increased $SiO_2$ and K.

• Resources Recycling
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• v.26 no.6
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• pp.38-44
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• 2017

As by-pass dust (BPD) made from cement manufactured process is designated waste, it is required to bury as high cost. The main component of BPD is potassium chloride (KCl), and used for the fertilizer. For using KCl to the fertilizer, the pH value of KCl is required as neutral or weak acid. However, it is not suitable to apply BPD into the fertilizer directly without any other treatment because BPD's pH value is shown 12.0~12.5; a high base. In this study, the carbon dioxide ($CO_2$) was used for removing calcium oxide (CaO) and reducing pH value during manufacturing process of KCl. We fixed inner condition of the carbon test chamber as $25^{\circ}C$-50RH%, and retained 0~7 hours under the 20 vol% of $CO_2$ atmosphere. After experiment, we analyzed the content of CaO and pH value from each samples. The more time exposed to $CO_2$, the content of CaO and pH value are shown. Furthermore, pH value exposed in 6 hours nearly reached 7.

• Korean Journal of Soil Science and Fertilizer
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• v.42 no.spc
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• pp.1-3
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• 2009

Silver nanoparticles have been used in agricultural practice because of their biocide effect. However, limited information is available for the effect of silver nanoparticles on soil quality. Therefore, the main purpose of this study was to evaluate effect of silver nanoparticle application on soil especially when fertilizer is applied. To simulate potassium fertilizer, potassium chloride was mixed with silver nanoparticles in soil. Concentration of silver and chloride was measured and result showed that concentration of both compounds was decreased at the range of $3.4mg\;kg^{-1}$ and 78-84% respectively after treatment. In addition, analysis of microbial population after treatment showed that microbial population was increased when silver nanoparticles and KCl were mixed. Those results indicated that application of fertilizer has impact on biocide effect of silver nanoparticles in soil.

• Korean Journal of Agricultural Science
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• v.42 no.4
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• pp.319-324
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• 2015

An estimation of the requirement of minerals based on growth stage and cropping pattern is very important for greenhouse zucchini. This study was performed at farmer's field which was applied with a fertigation system and a semi-forcing cultivation from Feb. to July in 2014, and nitrogen levels were set up with x0.5, x0.75, x1.0 and x1.5 of the NO3-N-based soil-testing recommendation for zucchini cultivation. Top dressing of nitrogen (basal : top = 4 : 6) and potassium (basal : top = 3 : 7) was applied with an interval of every two weeks from two and six weeks after transplanting, respectively, and phosphorus was totally supplied with basal dressing. The nitrogen uptake was the order of x1.0, x0.75, x1.5 and x0.5, phosphorus, x1.0, x0.75, x0.5 and x1.5, and potassium, x0.75, x1.0, x1.5 and x0.5. From these results, it was suggested that highest mineral uptake could be reached between x0.75 and x1.0 of the NO3-N-based soil-testing recommendation. In conclusion, nutrient management based on the growth stage was proven to be better method for favorable growth and yield of zucchini.

• Journal of The Korean Society of Grassland and Forage Science
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• v.25 no.4
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• pp.245-250
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• 2005

This experiment was conducted to compare the frech and dry matter yields and feed values of Sorghum$\times$Sudangrsss Hybrid in accordance with different nitrogen and potassium fertilizer sources at the Dae-Ho reclaimed tidal land, Korea from 2003 to 2004. Soil salt contents of ammonium sulfate plots(T3, T4, T5) were higher than that of the urea plot(T2), but that of potassium sulfate plot(T6) was the lowest. The fresh yields of ammonium sulfate plots(T3, T4, T5) and potassium sulfate plot(T6) were higher than that of the urea plot(T2) as $173\%,\;173\%,\;144\%\;and\;90\%$. respectively. The dry matter and total digestible nutrient(TBN) yields were similar tendency like the results of the fresh matter yields. The crude protein(CP), neutral detergent fiber(NDF) and acid detergent fiber(ADF) contents of ammonium sulfate plots(T3, T4, T5) were higher than those of urea plot(T2), but those of potassium sulfate plot(T6) were the lowest. On the other hand, TDN content in potassium sulfate plot(T6) was the highest. It was desirable to use ammonium sulfate$(20\~30kg\;N/10a)$ and potassium sulfate fertilizer$(15kg\;K_2O/10a)$ than those of urea and potassium chloride fertilizer on reclaimed tidal land in view of forage production and its feed value.

• Korean Journal of Soil Science and Fertilizer
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• v.7 no.1
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• pp.55-64
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• 1974

Effect of tow or three week potassium depression on nutrient contents in two rice varieties, Jinheung (a leading local) and IR 667-Suwon 214 (high yielding tropical line), was investigated at various growth stages in water culture system for the nutritional elucidation of potassium top dressing. According to potassium content, potassium ratio beween leaf blade and leaf sheath plus culm, relative potassium content ($-k/+k{\times}100$) and balance between potassium and other nutrients (K/N or K/Ca+Mg) it could be concluded as follows: 1) Rice plants have three sensitive growth stages to potassium stress in the orther of ear formation stage (20 to 30 days before heading) early tillering (15 to 25 days after transplanting) and at heading. 2) IR 667 is more sensitive to potassium stress than Jinheung, especially in early stage due to lower uptake of potassium. 3) Leaf sheath of IR 667 appears to have a role as potassium reservoir to greater extent than that of Jinheung.

• Korean Journal of Soil Science and Fertilizer
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• v.26 no.4
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• pp.230-235
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• 1993

This study was carried out to investigate the supplying capacity of various forms(Water soluble, exchangeable, and available) of potassium in soils of different site quality by using surface soils from the Japanese cedar(Cryptomeria japonica) forests in Cheju island. Major results can be summerized as follows. Using continuous leaching methods with 0.01N-HCl, accumulated amounts of available potassium from surface soils of site upper and site low were about 0.6me/100g and 0.4me/100g, respectively. The release ratio of available potassium in the first $1{\ell}$ leaching of 0.01N-HCl to the total available potassium leached with $6{\ell}$ of 0.01N-HCl was over 80% for both sites, and this suggester that surface soil of both sites had the weak potassium adsorptivity as the typical volcanic ash soil. The ratio of the exchangeable potassium to the water soluble potassium was 1 : 1 for both sites. The ratio of the exchangeable potassium to the available potassium was 1 : 1 for the site low but the smaller ratio value for the site upper, indicating that the potassium supplying power of the site upper was greater than that of the site low. Available potassium was highly correlated with exchangeable Ca($0.83^{**}$) and Mg($0.84^{**}$).

• Korean Journal of Soil Science and Fertilizer
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• v.14 no.1
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• pp.17-23
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• 1981

The effects of potassium chloride and potassium sulphate on the volatilization of ammonia from acidic clayloam and tidal sandy clay loam soils applied with urea under flooded conditions were studied in a laboratory experiment. Results obtained were as follows; 1. The application of potassium to the acidic soil promoted the volatilization of ammonia through increasing soil pH. 2. The application of potassium to urea treated on the tidal soil which lead pH over 8.0 under flooded reduced conditions decreased the wet soil pH and reduced the volatilization of ammonia from the soil. These effects of potassium were more pronounced in the potassium sulphate treatment than in the potassium chloride. 3. More ammonia was volatilized from the acidic soil applied with potassium sulphate, however, the effects of potassium fertilizers applied to the high pH tidal soil seemed to be masked by high salt content of the soil. 4. Urea brought up soil pH significantly. Potassium sulphate was more effective than potassium chloride in raising pH of the acidic soil, though the reverse could be true in the tidal soil with high pH. The reduction of sulphate might be a major cause for the pH change.