• Korean Journal of Soil Science and Fertilizer
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• v.2 no.1
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• pp.69-73
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• 1969

In order to improve nearly unarable soils, poor in humus and poorly drained coarse textured, derived from fluvio marine deposit; a factorial experiment have been conducted to find out the influence of compost, increased potassium application and split application of potassium on the yield and germination of soybean variety Haman. The result obtained arid discussed may be summarized as follows. (1) The soybean yield increase was significant by the application of compost, increased amount of potassium and split application of potassium. (2) The application of compost significantly increased the numbers of germination. (3) The increased amount of potash and split application of potash fertilizer showed an apparent effect on the increase of germination and grain numbers per plant. (4) There was a positive relation between the number of grains per plant and the number of pods per plant, however, the increased numbers of pods per plant has not a direct effect for the increase of soybean yield per unit area. (5) Above results suggests that the improvement of nearly unarable Woolsuk Island soils derived from fluvio marine coarse material may be possible by the application of compost, increased amount and split application of potash fertilizer.

• Korean Journal of Soil Science and Fertilizer
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• v.19 no.4
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• pp.297-300
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• 1986

A trial paste fertilizer for rice was manufactured by a developed process using major raw materials of waste liquid from glutamic acid fermentation, urea, phosphoric acid, diammomium phosphate and potassium chloride with potassium hydroxide for pH adjust and both glycerin and $HB_4O$ for enhancing and maintaining dispersion of paste. The ratios of N, $P_2O_5$ and $K_2O$ for trial products of paste fertilizer were 10:15:13 for Japonica var., and 12.5:15:13 for Indica var., and it was 6.0 in pH and 1.45g/cc in specific gravity.

• Korean Journal of Soil Science and Fertilizer
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• v.6 no.1
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• pp.29-31
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• 1973

Upon the assumption that the available components in the soil evaluated by present analytical procedures, are as effective as the components applied to the soil as fertilizer, some formulas for the calculation of fertilizer requirements (F. R) for crops are suggested. Basically, the formulas are derived by combining the country average values of soil test data(${\overline{ST}}$) and of the optimum rate of fertilizers (ORF) for crops obtained from N.P.K. trials in farmer's field, as following. $$F.R(kg/10a)={\overline{ST}}(kg/10a)+ORFkg/10a-ST(kg/10a)$$ where, ST denotes the available components tested in the soil under question. Although this formula can be used both for P and K fertilizers, considering the significance of the potassium saturation rate of the soil for the availability of K, for the calculation of K fertilizer requirement, following formula is suggested. $$F.R(kg/10a)=(C.E.C.{\times}B.S.R.K.-KST(me/100g){\times}CF$$ where, B. S. R. K. is the basic potassium saturation rate of the soil and CF is conversion factor for the conversion of K me/100g into $K_2O$ kg/10a. The B. S. R. K. for different crops are obtained from the country average values of soil exchangeable K (${\overline{KST}}$), cation exchange capacity (CEC) and the optimum rates of K fertilizers for crops (ORF $K_2O$). $$B.S.R.K.=\frac{{\overline{KST}}{\times}CF+ORF(K_2O)}{CEC{\times}CF}$$ Using these formulas, equations for P and K fertilizer requirements for rice, barley, wheat, corn, italian millet, soy bean, sweet potato, potato and rape are derived.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.5
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• pp.773-778
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• 2011

Long-term continuous application of livestock by-products to agricultural land may adversely affect the soil characteristics and the crop yield. Five year term study from 2007 was carried out to assess the effects of repeated application of low-concentration swine slurry on soil chemical properties including phosphate and heavy metal contents and yield of tomato (Lycopersicon esculentum) and cucumber (Cucumis sativus L.) in a greenhouse. Treatments were conventional chemical fertilizers and three application rates of low-concentration swine slurry (Slurry composting and biofiltration, SCB): 50%, 100%, and 200% of recommended nitrogen fertilization. For swine slurry treatment of 50% nitrogen, deficient nitrogen was supplemented with urea fertilizer. The soil phosphorus and heavy metal contents after five year continuous application of swine slurry were not significantly higher than those of chemical fertilizer use. Repeated application of the swine slurry alone for five years resulted in relatively high soil exchangeable potassium and sodium compared with chemical fertilizer treatment. Contents of heavy metals in leaves of tomato and cucumber did not show significant difference among treatments. Yields of the crops for the swine slurry were not significantly different from that of chemical fertilizer. The results imply that continuous application of the swine slurry may not influence levels of soil phosphate and trace elements in greenhouse soils but could accumulate potassium and sodium in the soil.

• Korean Journal of Soil Science and Fertilizer
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• v.40 no.5
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• pp.377-382
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• 2007

Porous mineral coating have been fabricated and applied for basic research on their slow release action to a fertilizer. Feldspar was selected as raw mineral for the coating and two different particle sizes of powder were prepared. Slow-release action was estimated by using a potassium sulfate fertilizer. Spherical pellets were prepared with a pan-type pelletizer and then screened into sizes ranging 1.4 to 2.35mm. While the fertilizer pellets were rotated in the pelletizer again, the feldspar powder and 0.5% polyvinyl alcohol solution were simultaneously sprayed on the pellets. The fertilizer pellets coated with feldspar powder were fabricated. The pellets were heated to increase their strength and screened to sort by coating thickness. Potassium releasing tests were conducted for 40 days and the performance for slow-release action was estimated as functions of the heating temperature, coating thickness and raw mineral powder size. The Burst effect caused high initial releasing rate. Releasing kinetics was proportional to concentration of potassium in pellets. The pellet that was fabricated with $27.4{\mu}m$-sized feldspar and heated at $1050^{\circ}C$ showed a releasing rate of 43% on the 40th day.

• Korean Journal of Soil Science and Fertilizer
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• v.23 no.3
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• pp.204-207
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• 1990

This study was conducted to evaluate the potassium availability of soybean grown on potted soil amended with 20% by weight of fly ash for two years of which the second year was done on its residual effect. Soybean growth was normal with incorporation of 20% fly ash. The increase in yield was accompanied by an increase in the potassium contents of plant and soil.

• Korean Journal of Organic Agriculture
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• v.9 no.3
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• pp.103-117
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• 2001

This study was inducted to investigate the effects of microbial fertilizers on the fields of young radish(Raphanus sativus L.), chemical components of plant and soil, and the microbial floras. Six microbial fertilizers, MPK+Husk+Palma, Husk+Palma, MPK+Compost, Compost, BIO Livestock Clean System(BLCS) cattle dropping, and Tomi were used. The yields of young radish were increased in six microbial fertilizer treatments. The fresh matter weight, the number of leaves, and the dry matter weight of young radish in BLCS cattle dropping treatment, the leaf length in MPK+Husk+Palma treatment, the sugar content in Husk+Palma treatment, arid the leaf width in Tomi treatment showed the highest amount, respectively. The effects of microbial fertilizers on chemical characteristics of young radish and soil were examined. Phosphoric acid amount of young radish in Tomi treatment was much higher than other treatments. Potassium amount of young radish showed high significance in all microbial fertilizer treatments compared with control, and shoved the highest in Compost treatment . Two components, phosphoric acid find potassium, in soil inoculated by microbial fertilizers showed significant. Phosphoric acid in the Tomi treatment and Potassium in Husk+Palma treatment were increased. The microorganic populations in soil inoculated with microbial fertilizers were examined. While the number of Bacillus in ceil was increased in MPK+Husk+Palma treatment, the numbers of total bacteria, actinomycetes, and fungi were increased in Tomi treatment.

• Journal of Electrochemical Science and Technology
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• v.2 no.3
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• pp.168-173
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• 2011

The availability, low toxicity, and high degree of technological development make silicon the most likely material to be used in solar cells, the cost of solar cells depends entirely on cost of high purity silicon production. The present work was conducted to electrodeposite of silicon from $K_2SiF_6$, an inexpensive raw material prepared from fluorosilicic acid ($H_2SiF_6$) produced in Iraqi Fertilizer plants, and using inexpensive graphite material as cathode electrode. The preparation of potassium fluorosilicate was performed at ($60^{\circ}C$) in a three necks flask provided with a stirrer, while the electro deposition was performed at $750^{\circ}C$ in a three-electrodes configuration with melt containing in graphite pot. High purity potassium fluorosilicate (99.25%) was obtained at temperature ($60^{\circ}C$), molar ratio-KCl/$H_2SiF_6$(1.4) and agitation (600 rpm). Spongy compact deposits were obtained for silicon with purity not less than (99.97%) at cathode potential (-0.8 V vs. Pt), $K_2SiF_6$ concentration (14% mole percent) with grain size (130 ${\mu}m$) and level of impurities (Cu, Fe and Ni) less than (0.02%).

• Korean Journal of Soil Science and Fertilizer
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• v.23 no.4
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• pp.293-296
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• 1990

The effect of wallastonite, potassium chloride and potassium sulphate on the ammonification and nitrification of urea was studied in a non-planted green house experiment, filling with 500g soil in plastic pot and incubating for 17 days. Potassium sulphate gave superior effect on the neutralizing soil acidity of wallastonite than potassium chloride and raised soil pH which promoted ammonification and subsequent nitrification of urea. Less than 20% $NO_3-N$ against the sum of $NH_4-N$ and $NO_3-N$ was accumulated in soils incubated bellow pH 6.0. It seemed that pH 5.2 to 6.0 was the critical range for the nitrification of ammonium, or raising the concentration of ammonia in soils to the toxic level to the nitrification. It appeared that the nitrification could be occuring in low moisture, air dried, conditions of soil.

• Korean Journal of Soil Science and Fertilizer
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• v.42 no.4
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• pp.301-306
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• 2009

This study was conducted to determine the physiological differences betweenhealthy and wilted plants with respect to nitrate assimilation and ascorbic acid content. Wilting was artificially induced in spinach plants by treating the seeds with nutrient solution containing high nitrogen and low potassium. The plants were cultured in different plots 4 types of media: 1N-1P-1K (control), 6N-1P-0K (0K), 6N-1P-0.5K (0.5K), and 6N-1P-2K (2K). The rate of wilting among the plants was as follows: control, 0%; 2K, 10%; 0.5K, 40%; and 0K, 70%. This shows that under high nitrogen conditions, the lower the amount of potassium provided, higher was the rate of wilting. There were no differences in plant growth among the plants treated with different levels of potassium under high nitrogen conditions.The nitrate content in both the leaves and the roots was higher in plants grown under high nitrogen media than those in the control. Furthermore, the nitrate level decreased with increasing potassium concentration. The ascorbic acid content of spinach under high nitrogen conditions was lower than those of the control.