• Korean Journal of Soil Science and Fertilizer
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• v.45 no.6
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• pp.998-1003
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• 2012

Pantoea agglomerans DSM3493 was isolated from green house soils collected from Chungchugnam-do province, Gongju-Gun area in South Korea and phosphate solubilization and organic acid production of the strain were assessed using three types of insoluble phosphate sources (Ca phosphate, Fe phosphate and Al phosphate) under three different pH conditions (7, 8 and 9). The highest Ca phosphate solubilization ($651{\mu}g\;mL^{-1}$) was recorded at pH 7 followed by pH 8 and 9 (428 and $424{\mu}g\;mL^{-1}$ respectively). The solubilization rate was found to be 80.4, 98.1 and $88.7{\mu}g\;mL^{-1}$ (for Fe phosphate containing medium) and 9.3, 12.1 and $29.8{\mu}g\;mL^{-1}$ (for the Al phosphate containing medium) respectively at pH 7, 8 and 9. Though increasing pH of the medium caused reduction in the rate of solubilization of Ca phosphate, solubilization of Fe and Al phosphates enhanced with increasing pH. By contrast, the highest amount of organic acid was produced with Ca phosphate while the lowest was recorded with the presence of Al phosphate. Among the organic acids, gluconic acid production was found to be the highest, followed by oxalic acid and citric acid regardless the source of phosphate. Results can thus be concluded that the production of organic acids appears to play a significant role in the inorganic phosphate solubilization.

• Korean Journal of Soil Science and Fertilizer
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• v.38 no.4
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• pp.188-193
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• 2005

Pantoea agglomerans immobilized in alginate solubilized four different rock phosphates efficiently under in vitro conditions. The solubilization pattern differed according to the rock phosphate source, where maximum solubilization of Morocco and Tunisia rock phosphates (215.6 and $186.1mg\;P\;L^{-1}$) on 6 days, Israel rock phosphate ($60.98mg\;P\;L^{-1}$) and tricalcium phosphate ($132.3mg\;P\;L^{-1}$) on 10 days and China rock phosphate ($48.8mg\;P\;L^{-1}$) on 12 days after inoculation was observed. The shelf life of the immobilized bacteria immobilized beads stored in two different temperatures was studied for six months. Beads stored at both room temperature as well as cold storage ($4^{\circ}C$) were found equally good in supporting the bacterial population as well as phosphate solubilizing activity. P. agglomerans immobilized in alginate might be exploited for large scale biosolubilization of rock phosphates intended for fertilizer use.

• Korean Journal of Soil Science and Fertilizer
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• v.46 no.5
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• pp.308-312
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• 2013

The monitoring of chemical dynamic changes in controlled horticultural lands is very important for agricultural sustainability. Field monitoring was performed to evaluate the soil chemical properties of 200 controlled horticultural soil samples in Gyeongnam province every 4 years from 2000 to 2012. Soil chemical properties such as pH, amount of organic matter, available phosphate, nitrate nitrogen, and exchangeable potassium, calcium, magnesium, and sodium were analyzed. The amount of exchangeable calcium and soil pH were significantly higher in 2012 than in 2000. In 2012, the frequency distribution for values of pH, organic matter, available phosphate, and exchangeable potassium, calcium, and magnesium that were within the optimum range was 16.0%, 22.5%, 11.5%, 3.5%, 2.5%, and 5.0%, respectively. Especially, available phosphate and exchangeable calcium were excess level with portions of 76.0% and 96.5%, respectively. These results indicated that a balanced management of soil chemical properties can reduce the amount of fertilizer applied for sustainable agriculture in controlled horticultural lands.

• Korean Journal of Soil Science and Fertilizer
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• v.30 no.2
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• pp.108-113
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• 1997

A field experiment was conducted to evaluate effect of phosphate coated slow release fertilizer on the directly seeded rice. Odae byeo was seeded by drill under dry condition. The soil was a sandy clay loam soil located in the Experimental Farm of the Kangweon National University, Chuncheon, Kangweon-Do. The yield of rice from the urea applicated directly seeded field was 84.9% of the yield from the transplanted field, and showed no difference between split application treatments. The yield from the phosphate coated slow release fertilizer was the highest showing 110.7% of the yield from the urea application. The yield from the polymer coated slow release fertilizer was 90.4%. The yield from the organic fertilizer 400kg/10a treatment was 81.8% and was 94.8% from the organic fertilizer 600kg/10a treatment. In 1996 experiment, the yield from the phosphate coated slow release fertilizer was higher than the yield from the transplanted field. The $NO_3-N$ and $NH_4-N$ concentrations in soil solution at the depth of 15cm revealed that nitrogen leaching was the highest from the urea N40-0-30-30 treatment, and the lowest from the phosphate coated slow release fertilizer. The phosphorus concentration showed similar pattern. Therefore, use of phosphate coated slow release fertilizer increased rice yield and decreased loss of nitrogen and phosphorus loss.

• Korean Journal of Soil Science and Fertilizer
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• v.9 no.4
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• pp.251-256
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• 1976

Langmuir adsorption maximum was used as a basis for the estimation of phosphate requirement as related to the application method to a newly reclaimed hilly land. The application rates of phosphate fertilizer were 4 levels corresponding to 5, 10, 20, and 30 percent of the Langmuir adsorption maximum which was determined by the laboratory experiment. The phosphate fertilizer was applied in two different methods of broadcast and band application. Yield of soybean on a newly reclaimed hilly land was greatly affected by the amount of phosphate fertilizer and application method. With the same amount of phosphate fertilizer, the soybean yield in the broadcast was always lower than that in the band application even though the yield in the broadcast increased with the application rate up to the highest level of this experiment. However, the yield in the band application showed steep increase up to 20 percent level and then the yield decreased at the highest level. The yield at the rate of 5 percent with the band application was equal to the yield at the rate of 20 percent with broadcast, and the yield at the rate of 10 percent with band application was higher by 17 percent than that in the highest broadcast rate. When manure was applied at the rate of 1000 kg/10a to the plot of the 10 percent band application, the yield was 14.6 percent higher than the yield of the plot of the 10 percent band application without the manure and was equivalent to the yield of the plot of the 20 percent band application.

• Korean Journal of Soil Science and Fertilizer
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• v.38 no.1
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• pp.15-24
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• 2005

Enterobacter intermedium oxidizes glucose to gluconic acid and sequentially converts gluconic acid to 2-ketogluconic acid (2-KGA) under aerobic condition. Shaking incubation of E. intermedium in a broth medium containing 22.5 g glucose, 8.2 g gluconic acid and 40 g rock phosphate per liter resulted in $1028mg\;L^{-1}$ soluble phosphate. The culture broth was used as phosphate bio-fertilizer (PBF) in this experiment. To evaluate PBF produced by E. intermedium on lettuce growth, five treatments (PBF1/3, PBF2/3, PBF3/3, BP, and MF) were used. In MF and BP treatments, $P_2O_5$ 5.9 kg of mineral fertilizer per 10a was added, while in PBF1/3, PBF2/3, and PBF3/3 treatments, culture broth containing one third, two third, and same amount of soluble $P_2O_5$ 5.9 kg per 10a was applied, respectively. At 20, 35, and 50 days after transplanting of lettuce, plant growth components, biomass, enzyme activities and soil chemical properties were analyzed. Dehydrogenase activity and available phosphate concentration of rhizosphere in phosphate bio fertilizer treatments (PBF1/3, PBF2/3, PBF3/3) were generally higher compared to MF and BP treatments. Soil biomass in PBF3/3 treatment was significantly higher than MF and BP treatments at early growth stage. However, there was no significant difference among all treatments with time. Plant fresh weights in PBF1/3, PBF2/3, and MF treatments were better than those in BP and PBF3/3 treatments. However, in PBF2/3 treatment the highest fresh weight was discovered where alkaline phosphatase activity was generally higher than other treatments at 35 and 50 days. Enhancement of lettuce growth at 35 and 50 days in PBF2/3 treatment was associated with greater phosphate uptake in lettuce tissue. As regarding all results, PBF showed better lettuce growth compared to mineral phosphate fertilizer where PBF2/3 treatment resulted in increase of lettuce fresh weight by 23% and phosphate uptake by 50%.

• Journal of the Korean Society of Tobacco Science
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• v.5 no.2
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• pp.3-7
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• 1983

Three levels of nitrogen, phosphate and potassium were applied to tobacco for the establishment of the optimum rate of the fertilizers for yield and quality. 1 . The rate increment of nitrogen and potassium increased tobacco growth, but phosphate were non - significant between rate. 2. The contents of total-nitrogen and total-alkaloid in the leaf were increased, with the increase of nitrogen rate while the effect of phosphate and potassium were negligible. 3. The yield and quality of the tobacco were increased with the increasing rate of nitrogen and potassium fertilizer but phosphate should little difference.

• Korean Journal of Environmental Agriculture
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• v.36 no.1
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• pp.1-6
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• 2017

BACKGROUND: Bone meal is commonly used as a phosphorus (P) fertilizer in organic farming. Effectiveness of bone meal was compared with mineral P fertilizer to elucidate the optimum application rates of bone meal in crop production. METHODS AND RESULTS: The effects of bone meal and fused phosphate on plant growth and P uptake were determined in a pot experiment with maize (Zea mays L.) in a clay loam soil. Bone meal and fused phosphate were applied at 150 and 300 mg $P_2O_5/kg$ soil, and maize was grown for 3 consecutive growth periods of 4 to 5 weeks each. As compared with fused phosphate, total shoot growth of maize per pot was 3-6% lower in bone meal fertilization, and the difference was not significant in the application of 300 mg $P_2O_5/kg$. At the same P application rate, uptake of P by maize plants was 7-9% lower in bone meal treatment. The P use efficiency in bone meal treatments ranged from 11.9-13.6%, equivalent to 73-84% of the efficiency for fused phosphate treatments. CONCLUSION: The equivalence of immediate effectiveness of bone meal as a P fertilizer was at least 90% compared with fused phosphate in the pot experiment with maize. The results indicate that bone meal could be a reasonable alternative to chemical P fertilizers.

• Korean Journal of Soil Science and Fertilizer
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• v.29 no.1
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• pp.8-14
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• 1996

Use of phosphate coated urea to decrease ammonia volatilization from directly seeded paddy under dryland condition at early stage was tested. Effect on urea hydrolysis was investigated through laboratory study comparing with use of thiourea, a urease inhibitor, under different water content. A field measurement of volitilized ammonia with phosphate-glycerol ammonia absorber was conducted for surface treated urea, phosphate coated urea, phosphate coated slow-release fertilizer and organic fertilizer. Through laboratory study, hydrolysis rate of phosphate coated urea at three days after treatment was lower than that of urea, however, the rate after one week was same. Thiourea addition retarted urea hydrolysis. By field measurement, ammonia volatilization was effectively reduced by use of phosphate coated urea.

• Korean Journal of Soil Science and Fertilizer
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• v.48 no.6
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• pp.588-592
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• 2015

Soil testing is one of the major strategies for establishing sustainable agricultural practice as it analyzes nutrient contents of soil and determines the amount of nutrients required for crop growth. Soil testing for the field cultivating regional major crops in Korea has been conducting by National Academy of Agricultural Science (NAAS), provincial agricultural research & extension services and agriculture technology centers since 2000. 1,006,227 soil samples were analyzed and uploaded on Korean soil information system (http://soil.rda.go.kr) from 2003 to 2013. Soil pH has changed from 6.1 to 6.2. Organic matter (OM), available (Avail.) phosphate and exchangeable (Exch.) K have decreased from 24 to $23gkg^{-1}$, 541 to $399mgkg^{-1}$ and 0.90 to $0.72cmol_ckg^{-1}$ between 2003 and 2013, respectively. Especially, Exch. Ca contents decreased to $5.7cmol_ckg^{-1}$ in 2009 and increased to $6.2cmol_ckg^{-1}$ in 2013. Ratios of optimal ranges for cropping were 48% for pH, 22% for OM, 26% for Avail. phosphate, and 23, 16, 22% for Exch. K, Ca and Mg in 2013. Ratios of optimal ranges for pH increased and low ranges for OM, Avail. phosphate and Exch. K increased. Frequency distribution was 64% for pH 5.5~7.0, 65% for OM $10{\sim}30gkg^{-1}$, 48% for Avail. phosphate under $300mgkg^{-1}$ and 23, 29, 22% for Exch. K 0.2~0.6, Ca 4.0~6.0 and Mg $1.0{\sim}1.5cmol_ckg^{-1}$.