• Journal of Biosystems Engineering
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• v.23 no.2
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• pp.105-114
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• 1998

Granule application with a boom has merits of accurate application and high field efficiency. In order to develop a boom granule applicator, aerodynamic properties of agrichemicals should be investigated. This study was accomplished to investigate aerodynamic properties of granules and factors affecting on them. The tested agrichemicals were urea, compound fertilizer (17-21-17), sand and zeolite. Basic physical properties of granules such as true density, sphericity, and arithmetic mean diameter for those materials were analyzed. Regression equations for pickup velocity (v$_{p}$) and saltation velocity (v$_{s}$) were proposed by the data transformation and the multi-regression analysis as follows : (equation omitted) where, 0< s < 1, 0< λ$_{i}$< 3, 35 < D/d$_{p}$ < 350, 1000 $_{p}$/p$_{a}$ < 2500 The range of pickup velocity of fertilizers and other agrichemicals were shown to be 10-16m/s and 9-13m/s, respectively. The saltation velocity of fertilizer and other agrichemicals were 3 m/s and 4 m/s, respectively.y.ively.y.y.

• Korean Journal of Soil Science and Fertilizer
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• v.20 no.3
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• pp.217-221
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• 1987

Two trial products of monogranular compound fertilizer for red pepper under vinyl mulching cultivatin were made using the principal sources of urea, diammonium phosphate and muriate of potash in combination with fillers of treated human wastes (product I) and zeolite (Product II). A field experiment was carried out to evaluate their effects on red pepper and the results obtained were as follows. Red pepper plant growth and total red fruit yields in the trial products of one time basal application were better and higher than those of NPK split application of contrl plot. The increases of yield in the trial products might be due to steady supply of nutrients for the entire growing period. Therefore, one time basal dressing of a developed monogranular compound fertilizer for red pepper was applicable under vinyl mulching cultivation.

• Korean Journal of Soil Science and Fertilizer
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• v.36 no.6
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• pp.357-366
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• 2003

This study was conducted to develop n convenient and efficient granular type absorbent with high CEC from powdery zeolite, which is a waste produced while crushing the natural zeolite of Korea to get a particular particle size. The change of mineralogical characteristics during hydrothermal alternation of natural zeolite to Na-P zeolite in alkaline solution at various reaction times was determined by X-ray diffraction (XRD), scanning electron microscopy (SEM), and total elemental analysis. The columnar aggregate of Na-P Zeolite was produced by calcinating the natural zeolite-charcoal extrudates of about 3 mm diameter. In 24 hours reaction, clinoptillonite, mordenite and feldspar in natural zeolite were disappeared by 3 N NaOH treatment, while Na-P Zeolite with spherical granular structure was newly detected by XRD. As increasing reaction time, Si/Al ratio in remaining solution was deceased. The CEC of the synthesized material increased more than 2 times compared with that of natural zeolite, although the diameter of Na-P zeolite were rather increased.

• Korean Journal of Soil Science and Fertilizer
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• v.29 no.3
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• pp.255-263
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• 1996

This study was conducted to evaluate the application effects of three different granular fused magnesium phosphate products on soybean in a volcanic ash upland soil(Namweon series) of Cheju island. They were two domestic products(Kyunggi Chemical Industrial Co., LTD, Pungnong Biryo Industrial Co., LTD) and an imported Chinese product that were manufactured from different added materials. A powder fused magnesium phosphate. a single superphosphate(water soluble phosphatic fertilizer) and a fused superphosphate(mixed water soluble phosphate and 2% citric acid soluble phosphate) were presented as check fertilizers. Yield of soybean was the highest in the Pungnong product of granular fused magnesium phosphate. the next was the Chinese product imported and the Kyunggi product was the lowest but there was no statistical significance among the three granular products of fused magnesium phosphate. There was no clear tendency between yield and yield components of soybean plant however, the effects on the number of mainstem nodes, number of branches nodes and number of pods per plant were observed in the increased yield treaments. Phosphate concentration in stems and pods of soybean plant at harvesting stage was higher than those in stems of soybean plant during growing period. Uptake amounts and recovery rates of phosphate in stems and pods of soybean plant at harvesting stage were similar with the yield increasing tendency on soybean. In the changes of soil pH at different periods, the application of phosphatic fertilizers was increased soil pH. Soil pH in Chinese product was higher than domestic products, but it was similar to single superphosphate. The available silicate concentrations of soil were higher in the plot of Pungnong product than Chinese product.

• Korean Journal of Soil Science and Fertilizer
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• v.18 no.2
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• pp.201-207
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• 1985

The experiments were conducted in order to evaluate the effect of a compound fertilizer for application of potato plants (Sumi) which were prepared by the Kyonggj Chemical LTD. The results were summarized as follows; 1. Comparing with the plot of 12kg/10a muriate of potash plot, the potato yield of compound fertilizer, double rate of potassium sulfate and normal rate of potassium sulfate plots were increased in order to 44%, 7% and 6% respectively. The yield of potato at the compound fertilizer were significantly higher than that of double rate of potassium sulfate, but the latter yield was lower that of control. 2. The yield of potato were to exeeding of final tuber on June 25, which was twelve day earlier than the actual harvest the application of the compound fertilizer may make possible to harvest potato eariler than normal season and benefit fammers which better economic return. 3. Manufacturing it with granular form at diammonium phosphate, ammonium sulfate and potassium sulfate as majour source materials and having little urea contents, the compound fertilizer raised higher the emergence rate of potato plant than the other fertilizer were promoted the early plant growth, and kept potato plants comparatively healthier than the other fertilizer even at later stage of plant growth.

• Korean Journal of Soil Science and Fertilizer
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• v.39 no.3
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• pp.151-156
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• 2006

This study was conducted to investigate effects of granular silicate fertilizer(GSF) on growth, nutrient uptake and quality rice during cultivation. Then the chemical properties of paddy soil used for the cultivation test were pH 5.9, O.M. $13.7g\;kg^{-1}$, avail. $P_2O_5$ $48.9mg\;kg^{-1}$, and avail. $SiO_2$ $79.8mg\;kg^{-1}$. The amounts of GSF treated in the paddy soil were 0, 76, 185, 229, 413 and $489kg\;10a^{-1}$ for control, S-100(control amounts of soil available $SiO_2$), S-130, S-160, S-190 and for S-210 treatments, respectively. At results of rice growth leaf length and tiller number were more remarkable results at treatments of GSF than control. The leaf length of rice at S-100 treatment was the highest as 99.4 cm and the tiller number was the highest as 18.9 ear number at S-130 treatment. At the results of rice yield parameters, the grain and straw yield of rice were showed that all of the GSF applicated treatments were more predominant level than at the control, especially their levels were the highest values as 841.5 and $815.2kg\;10a^{-1}$ at the S-160 treatment, respectively. Also at the results of quality parameters on rice grain, a perfect kernel in the GSF applicated treatments was more increased than at control, but a broken kernel rate was inversely decreased. In results of these aspects, the chemical properties of white rice and the taste of rice by the Toyo MA-90A(Toyo rice quality taster) instrument, amylose content was the lowest value as 18.7%(generally about 20%) at S-160 treatment. Also, Mg/K ratio and rice taste value were the highest level as 0.58 and 69.1 at the S-190 and S-160 treatments respectively. The harvest yields of rice at S-160 and S-190 treatments from these growth factors were more produced about 8-13% than control. Therefore, the GSF application for rice cultivation from these results should be expected to obtain the positive effects as enhancement of rice harvest yield and improvement of quality on the cooked rice taste. Amount of GSF application could be recommended as around $200mg\;kg^{-1}$ for optimal and economical rice cultivation.

• Korean Journal of Soil Science and Fertilizer
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• v.32 no.4
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• pp.446-451
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• 1999

This study was carried out to investigate some mineralogical characteristics of Artificial Granular Zeolite (AGZ) and effect of AGZ on purification and alleviation of rice seedling damages of mine wastewater containing heavy metals. AGZ had mainly representative Na-P1 peaks and some $C_3S$ peaks of Portland cement in X-ray diffractogram. Differential thermal analysis represented that AGZ had weak endothermic peak around $130^{\circ}C$ and new deep endothermic peak around $750^{\circ}C$ as compared to powdery artificial zeolite. The ranking of heavy metals removals by AGZ, was lead> copper> cadmium> zinc in the synthetic wastewater. Root growth of rice seedling was greatly inhibited in the mine wastewater, and died after all. As AGZ treated into the mine wastewater with the ratio 1 : 50 (W : V) for one day or 1 : 100 for 4 days, the concentrations of heavy metals in the mine wastewater were decreased to below the critical concentration for agricultural use. And rice seedlings were grew with little damages in the purified water by AGZ.

• Korean Journal of Soil Science and Fertilizer
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• v.10 no.2
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• pp.79-84
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• 1977

In order to confirm the effect of potash top dressing and to observe the effect of N, K compound fertilizers, 17-0-17, 17-0-14, and 15-0-20, specially prepared for top dressing to rice, a field experiment with rice (Oryza Sativa L., Akibare) was conducted in a poorly drained paddy field in comparison with potassium chloride. The results obtained are as follows, 1. The effect of potash top dressing to rice was so remarkable that the yield from the plots of split application of muliate potassium or compound fertilizer was significantly higher than that from the plot received no potash at all. In contrast, the plots received all the amount of potash as one dose at transplanting time showed no significant increase in yield compared with that of potash plot. 2, The effect of N, K compound fertilizer, granulated to about the size of a small bean appeared to be so slow that it gave little increase of yield when it was appiled as a top dressing at the primodial stage, but it gave an increase of yield when it was top dressed at effective tillering stage. 3, Granular N, K compound fertilizer to be top dressed at primodial stage might be prepared in small size so that the fertilizer readily go into solution when it was applied, otherwise the fertilizer should be applied eariler than the primodial stage.

• Korean Journal of Soil Science and Fertilizer
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• v.29 no.2
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• pp.113-123
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• 1996

This experiment was carried out to compare with the physico-chemical properties of granular fused magnesium phosphates which were two domestic products(Pungnong Biryo Industrial Co., LTD and Kyunggi Chemical Industrial Co., LTD) and a imported Chinese product. The changes of pH, distribution of particle size, disintegration in water and in soil, hardness in soil, chemical composition, and dissolution rates in water, in soil and in 2% citric acid solution were investigated. The changes in pH were bigger in Jungmun series(black volcanic soil), in the imported chinese product, and in Jungmun series with the larger quantities applied. The domestic products were lower in pH, calcium, alkalinity and 1/2N-HCl soluble silicate than the Chinese product but total(Aqua regia) soluble phosphate, 2% citric acid soluble phosphate, 1/2N-HCl soluble and 2% citric acid soluble magnesium, and 2% citric acid soluble manganese concentration were similar among the domestic products and the imported product. In particle sizes, Chinese product was the biggest, Kyunggi product was the next, and Pungnong product was the smallest. The changes of disintegration rate in water and in soil were smaller in Pungnong and Kyunggi products at the early days of dissolution, and there were decreased with the order of Kyunggi product> Chinese product> Pungnong product at the latter days. The hardness of the products in soil was the strongest in Kyunggi product, the next was Pungnong product and Chinese product was the weakest so as to hardly measurable. The changing dissolution rates of 2% citric acid soluble phosphate concentration of granular fused magnesium phosphate products were the highest in Kyunggi product and the lowest in Pungnong product at the early days, the three products were dissolved over 90% within 50 days, and there were no clear difference among the products after 70 days of dissolution. The dissolution rates of 2% citric acid soluble phosphate concentration of granular fused magnesium phosphate products in soil were the highest in Pungnong product and Chinese product was the lowest, but they were less than 60% in 100 days of dissolution.

• Korean Journal of Soil Science and Fertilizer
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• v.20 no.2
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• pp.97-100
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• 1987

Medium grade mongranular compound fertilizers for the crops under vinyl mulching cultivation were formulated using the principal materials of urea, DAP and MOP in combination with various fillers of zeolite, gypsum and treated human waste and granulated with waste liquid of glutamic acid fermentation as binder. The ratios of $N-P_2O_5-K_2O$ of trial products were 12-10-11.5 for red pepper, 8-8-6 for sesame and 4-9-14 for peanut. The rate of dissolution of trial products was comparatively low in water. The product for red pepper had N dissolution rate of 80 percent during 24 hrs. 70 for peanut and 55 for seasame. The optimum dissolution rate has reported to be 50 percent by the standard laboratory dissolution test for 24 hrs. in water. Therefore, the slowly released characteristics were obtained with the products that had 24 hrs. dissolution of 70 to 60 percent. One time basal application of trial products could readily be justified under muching cultivation.