• Journal of Environmental Health Sciences
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• v.31 no.4 s.85
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• pp.280-286
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• 2005

The purpose of this investigation was to evaluate removal efficiency of $NH_4-N$ using the soil column. Soil, oyster shell and natural zeolite were used as a supporting media of soil column. Removal efficiencies of $NH_4-N$ were $35.9\%,\;41\%\;and\;93.4\%$ for the soil column packed with soil, natural $zeolite(20\%)$ and oyster $shell(20\%)$ at HRT of 72 hours, respectively. The addition of $20\%$ oyster shell to the soil accelerated nitrification in soil column. The influent ammonia nitrogen was mostly converted to nitrate nitrogen in the soil column and little ammonia nitrogen was found in the effluent. When the influent $NH_4-N$ concentration was 200 mg/l, the NIL-N removal was decreased at HRT of 48 hours, while nitrification was significantly increased after mechanical aeration. It was suggested that nitrification from higher $NH_4-N$ concentration was more affected by aeration in soil column process. The number of nitrifiers was approximately in a level of about $10^6\;MPN/g{\cdot}soil$ in the soil column mixed with oyster shell ($20\%$).

• Korean Journal of Soil Science and Fertilizer
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• v.29 no.4
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• pp.353-359
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• 1996

Micro plot study was conducted to elucidate the behavior of nitrogen derived from animal manure in soil and to obtain the fundamental information on animal waste management. Soils used in this experiment were sandy loam and loam. Soil water samplers (1m length ceramic cup tube) were installed at 90cm depth of soil to collect the percolate. Fresh and fermented pig manure were applied at the rate of 0, 50, 100 ton per ha. Maize was grown to evaluate the effect of crop on nitrogen behavior through soil profile. Concentration of nitrate nitrogen in percolate increased by application of pig manure. This trend was more obvious at the loam with fermented pig manure than sandy loam with fresh pig manure treatment. The concentration of nitrate nitrogen was lower under the maize cultivation than bare soil condition by 64.6-68.9%. Concentration of Ca, Mg and Na of soil and percolate increased as nitrate nitrogen concentration increased. The equivalent ratio of cation to nitrate nitrogen of percolate was increased by application of pig manure. This result showed that canon leaching was accompanied by nitrate nitrogen. Concentration of nitrate nitrogen of subsurface soil was increased by pig manure application.

• Korean Journal of Organic Agriculture
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• v.22 no.4
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• pp.719-730
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• 2014

This study was conducted to select proper soil amendments in order to reduce the occurrence of potato scab and maintaining soil health by applications of dolomitic lime, sulfur, potassium sulfate, shell meal fertilizer, silicate fertilizer, lime nitrogen and ammonium sulfate fertilizer in different pH levels of volcanic ash soil with continuous cultivation of potato. In potassium sulfate-applied plot with a low soil pH, the incidence rate and disease severity of scab were lowest at 84.4% and 28.4%, respectively. Those were lowest among the treatments. Value of potato scab control was 12.3% and marketable yield of potato was highest at 93.2%. In lime nitrogen-applied plot (60 kg/10a), the incidence rate was low at 38.3%, and control value was 23.8% and marketable yield of potato was high at 66.3%. In relatively higher pH soils, the incidence rate of scab was lowest at 38.3% in the lime nitrogen-applied plot (60 kg/10a). Value of potato scab control was 23.8%, which was four times higher than that in sulfur-applied plot. Marketable yield of potato was highest at 66.3% in the lime nitrogen-applied plot. In the lime nitrogen plot infected with potato scab pathogen such as S. acidiscabies and S. scabiei were remarkably lower than other soil amendments at 2.5, 5, and 10 g/L concentrations of lime nitrogen using Glucose Yeast Malt (GYM) medium. In conclusion, this study suggests that potassium sulfate application in low pH soil (less than pH 5) and lime nitrogen application in relatively higher pH soil (more than pH 6) before potato seeding might be helpful to reduce the occurrence of potato scab.

• Korean Journal of Environmental Agriculture
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• v.41 no.4
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• pp.230-235
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• 2022

BACKGROUND: Ammonia gas emitted from nitrogen fertilizers applied in agricultural land is an environmental pollutant that catalyzes the formation of fine particulate matter (PM2.5). A significant portion (12-18%) of nitrogen fertilizer input for crop cultivation is emitted to the atmosphere as ammonia gas, a loss form of nitrogen fertilizer in agricultural land. The widely practiced method for fertilizer use in agricultural fields involves spraying the fertilizers on the surface of farmlands and mixing those with the soils through such means as rotary work. To test the potential reduction of ammonia emission by nitrogen fertilizers from the soil surface, we have added N, P, and K at 2 g each to the glass greenhouse soil, and the ammonia emission was analyzed. METHODS AND RESULTS: The treatment consisted of non-fertilization, surface spray (conventional fertilization), and soil depth spray at 10, 15, 20, 25, and 30 cm. Ammonia was collected using a self-manufactured vertical wind tunnel chamber, and it was quantified by the indophenol-blue method. As a result of analyzing ammonia emission after fertilizer treatments by soil depth, ammonia was emitted by the surface spray treatment immediately after spraying the fertilizer in the paddy soil, with no ammonia emission occurring at a soil depth of 10 cm to 30 cm. In the upland soil, ammonia was emitted by the surface spray treatment after 2 days of treatment, and there was no ammonia emission at a soil depth of 15 cm to 30 cm. Lettuce and Chinese cabbage treated with fertilizer at depths of 20 cm and 30 cm showed increases of fresh weight and nutrient and potassium contents. CONCLUSION(S): In conclusion, rather than the current fertilization method of spraying and mixing the fertilizers on the soil surface, deep placement of the nitrogen fertilizer in the soil at 10 cm or more in paddy fields and 15 cm or more in upland fields was considered as a better fertilization method to reduce ammonia emission.

• Korean Journal of Soil Science and Fertilizer
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• v.30 no.1
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• pp.84-88
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• 1997

To establish N fertilizer recommendation method based on nitrate content of the soil for the Chinese cabbage grown in the plastic film house. Chinese cabbage was grown in the pots containing the plastic film house soils with various levels of $NO_3{^-}-N$ and different levels of fertilizer N. The nitrate nitrogen showed the positive correlation with nitrogen uptake amount by plant and the negative correlation with fertilizer nitrogen use efficiency of plant. The content of nitrate nitrogen in soil for maximum yield of Chinese cabbage was 310 mg/kg. An equation for the recommendation of fertilizer N for Chinese cabbage based on $NO_3{^-}-N$ in the soil was suggested.

• Journal of Environmental Science International
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• v.5 no.4
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• pp.525-533
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• 1996

Chemical characteristics of the industrial wastewater sludge, degradation of the sludge in soil and CO2 generation and changes of nitrogen in soil treated with the sludge were investigated. The results obtained were summarized as follows: 1. Degradation rate of the sludge in soil was 26% at natural temperature, and 33% at incubation temperature at 12 weeks after treatment. 2. T-C, T-N and the C/N ratio of sludge in soil was 16.0%, 0.63% and 26, respectively, at natural temperature, and 15.0%, 0, 65% and 23, respectively, at incubation temperature at 12 weeks after treatment. 3, Camulative CO2 generation in soil treated with l%, 3% and 5% of sludge was 284, 440 and 512 mg/100 g, respectively, at natural temperature, and 440, 558 g and 654 mg/100g, respectively, at incubation temperature at 12 weeks after treatment. 4, Changes of :norganic nitrogen in soil treated with l%, 3% and 5% of sludge were 7.8, 12.8 and 16.3 mg/100g, respectively, at incubation temperature at 12 weeks after treatment. Mineralization ratio of organic nitrogen in soil treated with 1%, 3% and 5% of sludge was 10.7%, 13.6% and 15.2%, respectively, at incubation temperature at 12 weeks after treatment. 5. Chanties of pH in soil treated with 1%, 3% and 5% of Industrial wastewater sludge were in the range of 6.7~7, 5 at natural temperature, and 6.1~7.9 at incubation temperature at 12 weeks after treatment.

• 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.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.44 no.2
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• pp.102-105
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• 1999

Mineralization of organic N is an important factor in determining the appropriate rate of organic matter application to paddy fields. A kinetic analysis was conducted for nitrogen mineralization of rice, barley, Chinese milk Ovetch (Astragalus sinicus L.; MV) and narrow leaf vetch straw in paddy soil. Nitrogen immobilization occurred rapidly and its rate increased in straw with high C/N ratio. The amount of nitrogen mineralization was rapid in the first year of rice-vetch cropping system. The rate constant (K) depended on the C/N ratio of organic matter. Mineralization of straw increased at high temperature. The amount of available N increment resulted in fast mineralization of straw, especially in rice and barley straw. Chinese milk vetch had the greatest mineralization rate at all temperatures and fertilization levels followed by narrow-leaf vetch. However, rice and barley straws with high C/N ratio immobilized the soil N at the initial incubation duration. Chinese milk vetch or narrow leaf vetch was not effectively mineralized in mixed treatments with rice or barley straw. The mineralization rate of organic matter was mostly affected by the C/N ratio of straw and temperature of incubation. Organic matter with low C/N ratio should be recommended to avoid the immobilization of soil N and the increasing mineralization rate of straw.

• Korean Journal of Soil Science and Fertilizer
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• v.16 no.2
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• pp.131-155
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• 1983

Though it has been widely known the nitrogen effects are influenced by soils, varieties, and mineral nutrients in the rice culture, few analyses in relation to the factors increasing nitrogen effect have been studied in Korea. The effects of potassium and silica on the factors increasing nitrogen effects in paddy soils were investigated in accordance with soil improvement practices and nitrogen application methods for the cultivated varieties. The results obtained are as follows. 1. For 413 paddy fields, the yield from soils without nitrogen application ranged from 200 to 850kg/10a and that from nitrogen application did 350 to 1,051kg/10a. The yield increament by nitrogen application varied 50 to 650kg/10a depending on soils. 2. Soil chemical characteristics for high yield were different between with nitrogen and without nitrogen application. In the without nitrogen application, however, contents of organic matter, phosphorous, potassium and calcium of high yield soils were lower than those of low yield, while the available silica content was higher in the former. 3. The yield increased with nitrogen application up to 22.4kg/10a and thereafter it decreased. These phenomena were supposed to be not be decrease of nitrogen uptake but by lowered silica uptake. 4. Clay soil incorporation, deep plough, and inorganic constituents control such as Ca, Mg, and $Sio_2$ were effective as soil improvement praitices. It was appeared that increases of silica content and Ca/Mg ratio were important to increase nitrogen effects. 5. For the correlation between yield and yield components, it was high between yield and panicle in low nitrogen level and so was it between grain yield and ripening rate in high nitrogen. 6. In the urea and super granule urea application plot, recovery rate of nitrogen by plant and soil was high and yield was remarkable high. 7. Regardless of fertilizer types such as ammonium sulfate and urea, the residual nitrogen was about 4kg/10a in both plots of 5.8 and 11.6kg/10a. N applied. 8. The potassium application to soil enhanced the nitrogen efficiency. It was more effective in low potassium soil. 9. Optimum pH value for gel formation in the 4% sodium silicate solution was approximately 6.6. 10. It was suggested that silica could affect to rice plant growth as the inorganic and organic chemical components.

• 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.