• 한국토양비료학회지
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• 제45권2호
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• pp.169-176
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• 2012

Among the major nutrients, phosphorus is by far the least mobile and available to plants in most soil conditions. A large portion of soluble inorganic phosphate applied to soil in the form of phosphate fertilizers is immobilized rapidly and becomes unavailable to plants. To improve the plant growth and yield and to minimize P loss from soils, the ability of a few soil microorganisms converting insoluble forms into soluble forms for phosphorus is an important trait in several plant growth-promoting microorganisms belonging to the genera Bacillus and Pseudomonas and the fungi belonging to the genera Penicillium and Aspergillus in managing soil phosphorus. The principal mechanism of solubilization of mineral phosphate by phosphate solubilizing bacteria (PSB) is the release of low molecular weight organic acids such as formic, acetic, propionic, lactic, glycolic, fumaric, and succinic acids and acidic phosphatases like phytase synthesized by soil microorganisms in soil. Hydroxyl and carboxyl groups from the organic acids can chelate the cations bound to phosphate, thereby converting it into soluble forms.

• 한국지하수토양환경학회지:지하수토양환경
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• 제16권5호
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• pp.31-41
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• 2011

The objectives of this study were to investigate the efficiencies of the stabilizers such as mono-potassium phosphate (MKP), phosphate fertilizer and red mud in treating the mine tailings contaminated with heavy metals and to characterize the changes in fractionations of the heavy metals during the stabilization. The TCLP results showed that the stabilization efficiencies of Cd, Pb and Zn increased with the increase in the stabilizer dosage and the reaction times. MKP showed the highest efficiencies for the heavy metals stabilization among the stabilizers tested. When the mine tailings were amended with MKP, the TCLP concentrations of Cd, Pb and Zn were reduced by 79~97%, 61~84%, and 89~99%, respectively. When the composite stabilizers, MKP/phosphate fertilizer or MKP/red mud, were used, the stabilization efficiencies were lower than when MKP was used as a single stabilizer. The sequential extraction results showed that carbonates fraction of Cd and Zn increased generally. Especially, when red mud was used, carbonates fraction of Cd and Zn increased 5 and 18 times, respectively. In the case of Pb, the treatment with MKP increased residual fraction by 10 times. The results showed that MKP was the most effective in stabilizing the heavy metals (Cd, Pb and Zn) to improve the efficacy of the composite binders.

• 한국환경농학회지
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• 제31권4호
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• pp.378-380
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• 2012

BACKGROUND: In Korea, green manure has been cultivated for reducing chemical fertilizer application, maintaining soil fertility, and feeding livestock in winter season. We evaluated the phosphate balance under green manure-rice cultivating system with different removal rates of green manure for maintaining soil fertility. METHODS AND RESULTS: The barley and hairy vetch mixture was selected as the green manure in this study. The barley and hairy vetch was sowed at a rate of 135 and 23 kg/ha, respectively, without fertilizer application. Total aboveground biomass was 12000 (barley: 5400 kg/ha, hairy vetch: 6600 kg/ha) kg/ha, and these green manure were incorporated with different input rates before rice planting. The input rates of green manure in this study were 0 (NPK+0%), 25 (NPK+25%), 50 (NPK+50%), 75 (NPK+75%) and 100 % (NPK+100) and the standard fertilization (NPK) without green manure cultivation. All treatments were applied with standard fertilizer (N-P-K: 90-19.6-48.3 kg/ha) before rice planting. The highest rice yield was observed in NPK+50% which was 20% higher compared with NPK. The phosphate balance with different incorporation rates of green manure was-104.0,-76.8,-52.9,-27.4, and 6.0 kg/ha for NPK+0%, NPK+25%, NPK+50%, NPK+75%, and NPK+100%, respectively. CONCLUSION(S): The use of green manure for livestock feeding in green manure-rice cropping systems could remove a huge amount of phosphate. This cropping system strongly requires phosphate application before green manure seeding for maintaining soil fertility.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2022년도 추계학술대회
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• pp.122-122
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• 2022

In order to investigate changes in rice yield and quality according to phosphate and potassium fertilization levels when nitrogen fertilizer was applied at 7 kg·10a^-1, a field experiment was conducted at National Institute of Crop Science of Korea in 2021. Three Korean rice varieties were grown in paddy fields, and phosphate and potassium fertilizer were treated at three levels(N-P-K 7-4.5-5.7 kg·10a^-1, 7-3-3 kg·10a^-1, 7-0-0 kg·10a^-1). When phosphate and potassium fertilizers were not treated, the yield of Ilpum and Chilbo was significantly reduced, and there was no significant difference in Hopyung. The head rice ratio was significantly lower in the untreated plot of Hopyung and Chilbo, but there was no significant difference in the Ilpum. Protein content was significantly decreased in the untreated plot of Chilbo, and there was no significant difference in other varieties. As a result of this study, it was confirmed that yield, head rice ratio, and protein content were lowered when phosphate and potassium fertilizers were not treated, and the degree of decrease was different depending on the variety.

• 한국작물학회지
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• 제31권1호
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• pp.24-29
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• 1986

참깨의 N, P, K 시비수준별 생육과 함유량, 지방산조성분포를 검토하여 얻은 결과를 요약하면, 1. 질소배비(16k/10a)시용시 초장과, 주당삭수, 착삭부위장, 분지수등은 증가되나, 삭당입수와 종실중은 표준비(8k/10a)에서 가장 많았다. 2. 가리의 배비(18k/10a)시용시에는 지상부 생육과 등숙비율이 모두 높았으며, 인산 및 가리, 배비구(N 8, P$_2$O$_{5}$ 8, $K_2$O 18k/10a)에서는 표준비(N 8, P$_2$O$_{5}$ 4, $K_2$O 9k/10a)의 종실중 91kg보다 11% 증가되었다. 3. 엽의 무기성분중 N과 $K_2$O는 파종후 20일에 가장 높았으며 이후 점차 감소되는 경향으로 N과 $K_2$O 배비시 엽의 N, $K_2$O 배비시 엽의 N, $K_2$O 함량은 증대되었다. 4. 시비수준별 함유량은 질소의 배비시용구(16k/10a)와의 P$_2$O$_{5}$ 표준시용구(4k /10a)에서 가장 많았으나, 가리에서는 차이가 없었다. 5. 지방산조성은 양질의 Oleic acid는 질소, 인산,가리의 배비구에서 가장 많았으며, Linoleic acid는 인산배비구에서 가장 높았다.

• 한국물환경학회지
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• 제34권3호
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• pp.316-327
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• 2018

Liquid fertilizers made from livestock manure contain high concentrations of nitrogen and phosphorus and thus are used as a fertilizer. However, excessive use of liquid fertilizer causes eutrophication of agricultural land and nonpoint source pollution. In this study, as a means of lowering the nutrient concentrations, struvite ($MgNH_4PO_4{\cdot}6H_2O$) production from the liquid fertilizer was investigated. When liquid fertilizers produced in Gyeonggido were analyzed, its characteristics differed by region and season, but the phosphorus concentration was commonly lower than that of nitrogen. When $K_2HPO_4$ and $MgCl_2$ were added to the liquid fertilizers, the optimal pH for struvite formation was pH 9.5. For environmentally friendly sources of magnesium and phosphate, ferronickel slag (FNS) and sewage sludge ash (SSA) were suspended in deionized water and extracted by sulfuric acid with various mass ratios. The optimum conditions for extracting FNS and SSA were 4.0 M sulfuric acid and 0.35 mass ratio of sulfuric acid to sewage sludge ash, respectively. For forming struvite, 0.233 L of SSA leachate (SSAL) was added into 0.3 L of liquid fertilizer containing 2,586 mg/L of ammonia and 110 mg/L of phosphate, pH was then adjusted to pH 9.5 using 10 M of NaOH. Afterwards 0.333 L of FNS leachate (FNSL) was added to this mixed solution. After a reaction for 1 hr at room temperature, the remaining concentrations of magnesium, ammonium, and phosphate were less than 50 mg/L, 500 mg/L and 150 mg/L, respectively, and 30 g of precipitates were obtained, most of which were struvite.

• 한국초지조사료학회지
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• 제20권2호
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• pp.85-90
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• 2000

Forage sorghum (Sorghum bicolor x S. bicolor) was cultivated for knowing the effect of alum sludge application on its root growth in a mountainous site, Kumsan. And the results obtained are as follows: The available P205 content in the soil seemed to decrease with the advance of level of alum sludge application. And plant P content decreased with the advance of sludge application without phosphate fertilizer. With phosphate fertilizer, root number of the forage was greater than that without the fertilizer. The root growth of forage sorghum was the highest with NPK and the least in control and alum application, and it is not recommended to apply NPK and alum together for the growth of the forage root. (Key words : Root, Sorghum, Mineral, Sludge, Kumsan)

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2002년도 총회 및 춘계학술발표회
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• pp.334-337
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• 2002

The drinking water industry faces a growing number of difficultiesin the treatment of groundwater for drinking water production. Groundwater sources are frequently contaminated with nitrates and phosphates due to usage of chemical fertilizer In this study, feasibility of micellar enhanced ultrafiltation (MEUF) was investigated to remediate groundwater contaminated with nitrate and phosphate. Ultrafiltration membrane was cellulose acetate with molecular weight cut off (MWCO) 10,000 and celtyl pyridinium chloride (CPC) was used to form pollutant-micelle complex with nitrate and phosphate. The results show that nitrate and phosphate rejections are satisfactory. The removal efficiency of nitrate and phosphate show 80% and 84% in single pollutant system, respectively with 3 molar ratio of CPC to pollutants. In the multi-pollutant systems, the removalefficiency increased to 90 % and 89 % for nitrate and phosphate, respectively, The presence of nitrate in the solutions did not affect the removal of phosphate and that of phosphate did not affect the removal of nitrate. The concentration of CPC in the permeate and removal efficiency of CPC was a function of the concentration of CPC in the feed solutions.

• 한국토양비료학회지
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• 제45권3호
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• pp.428-434
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• 2012

A fungal strain, capable of solubilizing insoluble phosphate under diverse temperature, pH and salt conditions was isolated from Waste Mushroom bed of Agaricus bisporus in South Korea. Based on 18S rRNA analysis, the strain was identified as Aspergillus awamori bxq33110. The strain showed maximum phosphate solubilization in AYG medium (525 ${\mu}g\;mL^{-1}$) followed by NBRIP medium (515 ${\mu}g\;mL^{-1}$). The strain solubilized $Ca_3(PO_4)_2$ to a greater extent and rock phosphate and $FePO_4$ to a certain extent. However $AlPO_4$ solubilizing ability of the strain was found to be very low. Glucose at the rate of 2% ($561{\mu}g\;mL^{-1}$) was found be the best carbon source for Aspergillus awamori bxq33110 to solubilize maximum amount of phosphate. However, no significant difference ($P{\leq}0.05$) in phosphorus solubilization was found between 1% and 2% glucose concentrations. $(NH_4)_2SO_4$ was the best nitrogen source for Aspergillus awamori bxq33110 followed by $NH_4Cl$ and $NH_4NO_3$. At pH 7, temperature $30^{\circ}C$ and 5% salt concentration (674 ${\mu}g\;mL^{-1}$) were found to be the optimal conditions for insoluble phosphate solubilization. However, strain Aspergillus awamori bxq33110 was shown to have the ability to solublize phosphate under different stress conditions at $30-40^{\circ}C$ temperature, pH 7-10 and 0-10% salt concentrations indicating it's potential to be used as bio-inoculants in different environmental conditions.

• 한국토양비료학회지
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• 제45권4호
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• pp.602-609
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• 2012

Burkholderia anthina R-4183, Burkholderia diffusa R-15930 and Burkholderia stabilis LMG 14294 isolated from green house soils (Gongju-Gun area, South Korea) were characterized and their phosphate solubilizing ability was assessed. Under in vitro culture conditions, all three species were proved to be effective in solubilizing phosphates in varying degrees. Strain Burkholderia anthina exhibited the highest phosphate solubilization in NBRIP medium ($665{\mu}g\;ml^{-1}$) followed by Burkholderia diffusa ($630{\mu}g\;ml^{-1}$) and Burkholderia stabilis ($578{\mu}g\;ml^{-1}$). However, solubilization of $FePO_4$ and $AlPO_4$ was found to be poor in all the strains. Acidification by means of gluconic and oxalic acids accumulation in the culture medium could be the possible mechanism responsible for phosphate solubilization. Glucose at the rate of 3% was found be the best carbon source for Burkholderia anthina while other two Burkholderia species showed maximum phosphate solubilization at 2% of glucose. In the case of nitrogen sources, ammonium and nitrate were equally effective in solubilizing phosphates by Burkholderia species. Despite a slight decrease in phosphate solubilization observed at increasing temperature, all three Burkholderia species could withstand a temperature of $30-35^{\circ}C$, pH at the range of 7-9 and the presence of NaCl (up to 2.5%) without much compromising the phosphate solubilization. As shown with potted mung bean seedlings, all the three isolates could enhance soil fertility and plant growth indicating their great potential to be used as bio-inoculants.