• Korean Journal of Soil Science and Fertilizer
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• v.4 no.1
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• pp.21-26
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• 1971

Present work is concerned with the effects of a soil amendment (a mixture of basic slag with trace elements Cu, Mn, Zn and B) on the phosphate uptake by rice plants and in improving yield of rice in low productive paddy soils. The experiment was conducted at Kimpo-myun, Kimpo-kun, Kyunggi province which is characterized as "Akiochi" area and split plot experimental design was adapted. The results are summarized as follows; 1. Combined effect of the soil amendment and phosphate applications on the grain yield is pronounced, which is also characterized by the increased grain weight, maturing rate and seed setting rate. 2. Treatment of soil amendment appears to improve phosphate efficiency; grain weight, maturing rate and seed setting rate are all improved as the rate of phosphate application increased. 3. Phosphate tends to accelerate plant growth at earlier stages of plant development while the soil amendment retards the growth, inhibiting excessive tillering. 4. The soil amendment increases silicate and manganese, but decreases phosphate, copper and Zinc contents in the rice plants.

• Korean Journal of Soil Science and Fertilizer
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• v.41 no.5
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• pp.342-347
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• 2008

Phosphate soubilized by microbes can be easily absorbed by plant as the element diffuses into soil solution. The microbes related to phosphate solubilizing activity are affected by the soil amendments such as rice straw compost, and lime. This study was performed to evaluate the effect of amendments to phosphate solubilizer in rice paddy soils. Available phosphate concentration was increased with the ratio of phosphate-solubilizing bacteria to aerobic bacteria in the rice paddy soils. The ratio was high in the plots applied with lime, silicate, and rice straw compost. Phosphate-solubilizing bacteria isolated from the soil were Aquasipirillum, Arthrobacter, Bacillus, Flavobacterium, Micrococcus and Micromonospora, Pseudomonas species. The highest dominant bacterial species was Pseudomonas, and Bacillus was followed.

• Korean Journal of Soil Science and Fertilizer
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• v.38 no.6
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• pp.334-339
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• 2005

Although phosphogypsum can have profound effects on both the physical and chemical properties of certain soils with supplying the essential elements, no widespread use of by-product phosphogypsum will be made unless such uses pose no threat to the public health and soil contaminations. This study was conducted to evaluate the effects of phosphogypsum on the growth of oriental melon and soil properties in plastic film house. Phosphogypsum was treated at the rate of $70kg\;CaO\;10a^{-1}$ and the effects were compared with the treatment of Ca-Mg carbonate. In the treatment of phosphogypsum, early growth of oriental melon was significantly increased comparing to the growth in the Ca-Mg carbonate treatment. Total fruit yield was not different between the treatments of phosphogypsum and Ca-Mg carbonate, but marketable fruit yield was higher in the phosphogypsum treatment. Although Ca and S contents in oriental melon were increased in the phosphogypsum treatment, contents of toxic heavy metals including As, Cd, Cr, Cu, and Pb were not different between the two treatments. Also, soil pH and contents of extractable toxic metals in the soil were not significantly different between the two treatments after the experiment. These results suggest that phosphogypsum can be a valuable substitute for lime materials in high pH soils of plastic film house.

• Korean Journal of Soil Science and Fertilizer
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• v.15 no.1
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• pp.34-48
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• 1982

1. Production and consumption of chemical fertilizers in Korea could be divided into five different phases of total imports, setting up fertilizer plants, self-sufficiency in production, net export, and diversification in compound fertilizers. Currently the nation has production capacity of 800 thousand M/T of nitrogen, 400 thousand M/T of phosphate ($P_2O_5$) and 200 thousand M/T of potash ($K_2O$). 2. Yearly consumption increased every year, since 1964, 28,000 M/T N, 7,700 M/T $P_2O_5$, and 7,500 M/T $K_2O$ until 1972, when the increase jumped by eight times for $P_2O_5$ and seven times for $K_2O$ for the following 3 years in anticipation of their short supply. Now total consumption has been more or less stabilized at the level of 450 thousand M/T N, 220 thousand M/T $P_2O_5$ and 180 thousand M/T $K_2O$ for the last 7 years. 3. Current operation rate of fertilizer plants is around 80% throughout the whole industry, after going through several different levels depending on demand at times. 4. Fertilizer export started in 1967 and reached a peak of 150 thousand nutrient ton in 1972, about 20% of total production, before temporarily stopping due to over-demand for next three years. The export resumed again in 1976 rise to the all time high of 670 thousand nutrient ton in 1980, almost half of total production, and then started to decline due to higher price of petroleum since then. 5. The decline in fertilizer export appears to be accelerated because several countries, in South-Eastern Asia, traditional export market for Korean fertilizers, started to build their own plants, since 1980, based on their raw materials of especially petroleum. 6. Current consumption in Korea is about 30 nutrient Kg per 10a, equivalent to that in Western European countries, partly due to new high-yielding rice varieties and extensive cultivation of fruit trees and vegetables. Additional fertilizer demand in future can be anticipated in reclaimed land for growing grass and forestry.

• Korean Journal of Soil Science and Fertilizer
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• v.31 no.3
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• pp.266-270
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• 1998

The identification of soil P level that exceed crop requirement is a prerequisite in implementing sustainable management of fertilizer and manure P to prevent soil and freshwater from contamination. To investigate the relationship between 0.01M $CaCl_2$ soluble P, and available P and P sorption capacity of 40 soils, P content and P sorptivity were analyzed. Single linear relationship revealed the dependence of 0.01M $CaCl_2-P$ on available P($r^2=0.479$), bioavailable P($r^2=0.281$), P sorption($r^2=-0.465$) and P absorption coefficient($r^2=-0.056^{NS}$). Thus available P as $P_2O_5$(AVP) and P sorption (PS) were most important factors in determining the concentration of 0.01M $CaC1_2-P$($CaC1_2-P$). In multinomial equation related $CaC1_2-P$ with AVP and PS, the determination coefficient was improved to 0.745. The logarithm of $CaC1_2-P$ was linearly related to AVP/PS. Consequently, the equation, $0.01M\;CaCl_2-P=0.1284e^{0.3288AVP/PS}$ could be suggested to estimate the concentration of P in 20mL of 0.01M $CaCl_2$ solution containing 2g of soil shaken for 17 hours.

• Korean Journal of Soil Science and Fertilizer
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• v.17 no.2
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• pp.161-166
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• 1984

The Cheju citrus orchards have been chemically fertilized with both phosphates high in Ca and Mg contents and potassium. The amount of chemical fertilizers consumed per unit area of cultivated land and the ratios of $P_2O_5$ and $K_2O$ to N in chemical fertilizers applied were much higher in the Cheju Island than those of the Korean mainland. These trends were particularly prominant in Southern Cheju where 70% of the Cheju citrus orchards are located. As the result of heavy applications of phosphate fertilizers, the available phosphorus of citrus orchard soils increased with increasing number of years under cultivation. The available phosphorus of sub-soil increased slightly with the number of years under cultivation compared to that of surface soil. Base saturation and pH increased with the number of years under cultivation, inasmuch as exchangeable bases such as Ca, Mg and K increased predominantly, but the cation exchange capacity did not vary in the citrus orchard soils.

• Korean Journal of Soil Science and Fertilizer
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• v.24 no.3
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• pp.159-164
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• 1991

A field microplot(D 20cm, L 85cm) experiment filled with Bonryang sandy loam soil (Typic Udifluvents) was conducted to obtain quantitative information on the movement of applied nutrients under diffetent soil moisture regimes and ladino clover cultivation. Chloride moved rapidly with soil water. When soil moisture tension was maintained at loer than 0.2 bar most of the Cl appeared to move outside the microplot 4 month after the microplot installation. Regardless of soil moisture condition, Cl was not detected in the soil due to the fast movement of the Cl beyond the microplot after 5.5 months Although large amount of P and water were applied to the soil of high available P during the field experiment, movement of P was negligible and most of P remained in thc place where applied due to the low solubility of the fused and superphosphate. Phosphate in the soil extracted by Bray No.1 solution and taken up by plant increased with soil moisture. Under the condition of irrigation at 0.2 bar, plant took up 23% of the applied P, and 24% of the P was extracted by Bray NO.1 solution, while plant took up 14% and 13% of the P was turned out to be Bray No.1 P. at thc nonirrigated condition after final harvest.

• Korean Journal of Soil Science and Fertilizer
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• v.40 no.5
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• pp.405-411
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• 2007

This study was carried out to measure insoluble phosphorus fractions content fixed in different soil type and isolate a superior phosphate solublizing bacteria(PSB) producing free phosphate in citrus orchard soil. Distribution of insoluble phosphate fraction ordered Al-P>Ca-P>Fe-P in the investigated citrus orchards. Insoluble phosphate fraction such as Al-P, Ca-P, Fe-P were higher in volcanic ash than in non-volcanic ash soil. A PSB with high holo zone in PDA-P medium isolated from citrus orchard soil. This strain identificated by MIDI system as Bacillus sphaericus. The optimum growth of pH and temperature were at 4~5, $30^{\circ}C$, respectively. When Bacillus sphaericus cultured at $25^{\circ}C$, 150 rpm condition in LB broth medium included different phosphate. Bacillus sphaericus produced free phosphate in the culture broth medium from tricalcium-phosphate(207.0 ppm), aluminium phosphate(324.5 ppm) and hydroxyapatite(334.8 ppm) and Phosphatase activity of Bacillus sphaericus was higher at $35^{\circ}C$ culture condition than that of $25^{\circ}C$. Two type preparation inoculated Bacillus sphaericus made with carrier materials such as Bentonite, $CaCO_3$, Sodium alginate. Density of PSB in this preparation conserved at $10^5c.f.u.\;g^{-1}$ level during storage in different temperature condition for 7 month. It also showed that free phosphate produced at PDA-P medium.

• Korean Journal of Soil Science and Fertilizer
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• v.36 no.4
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• pp.233-238
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• 2003

The effect of phosphate solubilizing microbes (PSM) on plant P uptake and growth in rock phosphate applied soil was tested under a greenhouse condition. Tobacco plants were grown in nonsterilized soil inoculated with Penicillium oxalicum CBPS-3F-Tsa with or without rock phosphate application as P fertilizer. Phosphorus concentration in tobacco plants was increased by the application of rock phosphate, while inoculation of soil with fungi further significantly increased P concentration in tobacco plants compared with the noninoculated treatments. Phosphorus uptake by tobacco plants was also increased by the application of rock phosphate and PSM inoculation, and the significant comparison has been made with single rock phosphate treatment. Growth of tobacco plant was also significantly increased in the treatments receiving rock phosphate, while the combined application of rock phosphate and PSM further increased plant growth. It was concluded that the positive effect of PSM inoculation on plant growth was closely related in plant P content and uptake. These results suggest that Penicillium oxalicum CBPS-3F-Tsa could solubilize insoluble soil phosphates and rock phosphate which can promote growth and P uptake of tobacco plants.

• Korean Journal of Soil Science and Fertilizer
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• v.32 no.2
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• pp.155-163
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• 1999

Nutrient balance during rice cultivation in the paddy of a local area under the environmental protection for drinking water supply was investigated. To compare nutrient balance in the paddy soil applied with different types of fertilization, 7 treatments were selected as followings : Recommended level of chemical fertilizers(R), Conventional fertilization(CF), Fresh cow manure(FCM), Cow manure compost(CMC), Straw compost+reduced chemical fertilizer(SCF), Fresh straw+recommended level of fertilizers(FSC), and no fertilization as control(C). Here, FCM, CMC and SCF were applied at the same level of total nitrogen as recommended in R. Rice yield was the highest in the recommendation(R) and fresh cow manure (FCM) treatments with $6,730kg\;ha^{-1}$(index 100), and followed by SCF (index 98), FSC (index 98), CMC(index 94), and CF(index 94). But statistically significant difference was not recognized among treatments except the control. Nitrogen infiltration loss was high in the simple chemical fertilizer treatments with $63kg\;ha^{-1}$ in CF and $58kg\;ha^{-1}$ in R during rice cultivation, respectively. Nitrogen infiltration loss was decreased below half level of chemical fertilizer treatments with cow manure treatments ($23kg\;ha^{-1}$ in FCM and $27kg\;ha^{-1}$ in CMC) and with reducing chemical fertilizer treatment by adding straw compost ($25kg\;ha^{-1}$). Phosphate was not leached during rice cultivation in paddy soil of a fluvial deposit type, in which oxidation horizon was developed broadly under around 15 cm depth of surface soil. Phosphate balance (A-B) was closed to 0 in all treatments except cow manure treatment (CMC), in which it was $+30kg\;ha^{-1}$ and show the possibility of over accumulation of phosphate by continuously replicated application of cow manure compost. Potassium balance was negative value in all but straw recycling treatment (FSC). It means that potassium was continuously supplied from soil minerals, uptaken by plants or eluted out of soil. In conclusion, by substituting inorganic fertilizer for organic fertilizer or reducing application rate of chemical fertilizer through mixing organic fertilizer, it would be possible to achieve the same rice yield as in the recommendation treatment and to decrease nutrient leaching below half level in rice paddy soil.