• Journal of The Korean Society of Grassland and Forage Science
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• v.14 no.3
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• pp.238-246
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• 1994

This experiment was carried out to determine the effects of seeding date and fall harvest method on the growth characteristics, forage yield and quality of winter rye(Seca1e cereale L.) at the forage experimental field, College of Agriculture and Life Sciences, SNU, Suweon from 5 September 1992 to 21 May 1993. The experiment was arranged in a split plot design with three replications. Main plots consisted of three harvests, no defoliation, cutting and grazing. Sub-plots consisted of seeding dates, early(5 September), mid(25 September) and late(l0 October). The results obtained are summari7d as follows; I . A 3-day difference in the first heading of rye was observed between no defoliation and fall grazing, while there was a 6day difference between early and late seeding dates. Therefore, the effect of seeding dates on the fist heading date of rye was larger than that of fall harvest methods. 2. CP content of rye with fall grazing was slightly higher averaged 16.5% compared with both fall cutting and no defoliated 1ye(15.6%). Mean CP content of rye at the early, mid and late seeding dates was 14.2, 14.5 and 19.1 %, respectively. 3. ADF content of rye was slightly higher with both fall cutting(29.99) and no defoliation(29.5%) than that of fall grazing(28.0%). ADF content of rye at the early, mid and late seeding dates was 30.7, 29.1 and 27.7%, respectively. Effect of fall harvest methods and seeding dates on NDF content of rye were similar to the observations made on ADF. 4. RFV and IVDMD of rye were lower with both no defoliation and fall cutting than fall grazing. but those of rye slightly increased with seeding dates progressed. 5. Dry matter yield of rye was the highest of 6,779 kg/ha with fall cutting, while the lowest yield of 6,240 kg/ha was obtained from no defoliation But no significant difference was found among the harvest methods. Dry matter yield of rye was significantly declined with later seedings. It is concluded that the highest forage yield of rye be possible from two harvest systems of fall and spring with earlier seeding rather than from one harvest system of spring.

• Korean Journal of Soil Science and Fertilizer
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• v.20 no.3
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• pp.285-299
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• 1987

Timing and placement of fertilizer applications are two managerial means to improve the fertilizer use efficiency. The relative importance of these two means is determined by the application rate. With the realistic rate of N application recommended to the small farmers in the tropics, at present and in the near future, basal application in right manner, seems to be more important than split application at different times. In wetland rice soils, deep placement by whatever available means is desirable. But in the situations where perfect deep placement is very difficult to implement, the whole-layer application may be worth trying, until better methods become available. In rainfed uplands, N fertilizer application plans should be contingent upon the amount and distribution of rainfall: apply a less risky rate as subsurface banding near the crop rows to start with; then, depending upon the rainfall prospects in the season, apply or omit the additional dose. Because the patterns of crop response to N fertilizer can be significantly different between the research farms and farmers' fields, it seems imperative to have information on the patterns of crop response to N under farmers' management conditions, for the development of realistic fertilizer application recommendations. To enable the farmers to adopt improved fertilizer application technologies, it is essential to develop and make available to farmers convenient fertilizer applicators. Past experience with the improved fertilizer use technologies indicates that, in the long run, the development of fertilizers that are not only effective and convenient for farmers to use but also easy to produce without major modifications of existing fertilizer production systems is the ultimate solution to the problem of low N fertilizer use efficiency.

• Journal of Sericultural and Entomological Science
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• no.12
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• pp.21-36
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• 1970

This studies have been carried out to 3nd various causes of cleanness defects on raw silk which has been increased since 1967 in Korea, so that this treatise may be a guide inform action to improve such a defect in future. The cocoon treatment for the proposed work was carried starting with in worst condition to find the critical limit of degrading through such a work. And various analysis have been also worked out using the annual silk testing data past a few years. The results obtained are as follows. 1. There was a great relationship between cleanness and neatness result. 2. Cleanness result is greatly influenced by mounting conditions and handling of cocoons, which brought 40 percent lower as cleanness result than standard ones in which caused minor defects, especially loops and split ends, so the bad mounting conditions and handling of fresh cocoons degraded raw silk from 4A grade to E. 3. The use of good water quality brought the difference of 1.04 percent in cleanness result rather than the use of bad one. 4. Well technical work brought the difference of 0.86 percent in cleanness result rather than poor technical work. 5, Satisfactory cocoon drying installation brought the difference of 1.97 percent in cleanness result rather than insufficient one. 6. Automatic reeling machine marked lower 1,55 percent in cleanness result than multi-end reeling machine. 7. The degrading of cleanness result from 1965 year silk to 1969 year silk marked 1.99 percent, which almost responds to the degrading rate from good to poor cocoon drying installed cleanness results. In view of this result, nowadays, insufficient cocoon drying installation may be main factor to be worse cleanness result of Korean raw silk. 8. The factors of cleanness defect in raw silk once supplied with cocoon into factory are water quality, technique evaluation, cocoon drying capacity and s： reeling machine. The relationship between cleanness result and above factors are as follows. cleanness result＝neatness result＋1.6－1.04(1－a)－1.97(1－b)－0.86(1-c)＋1.55${\times}$d a： The successive we ratio of water quality (0\longrightarrowl) b： The successive ratio of satisfactory cocoon drying installation (0\longrightarrowl) c： The successive ratio of well technical work (0\longrightarrowl) d： 1 in case multi-end reeling machine o in case automatic reeling machine 9, It is not admitted that there is heavy relationship between cleanness occurrence and nonbreaking reel ability. That mal$.$ be sowed with silk reeling technique. 10. The bad mounting conditions caused the worse result on the cocoon quality as much as cleanness. 11. Besides mounting conditions, there may be another factors affecting on the low reel ability of cocoons in Korea.

• Korean Journal of Soil Science and Fertilizer
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• v.46 no.4
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• pp.253-259
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• 2013

The use of subsurface drip fertigation using slurry composting bio-filtration (SCB) as nitrogen (N) fertilizer source can be beneficial to improve fertilizer management decision. The objective of this study was to evaluate effects of SCB liquid fertilizer by subsurface drip fertigation on cucumber (Cucumis sativus L.) yield and soil nitrogen (N) distribution under greenhouse condition. Cucumber in greenhouse was transplanted on April $4^{th}$ and Aug $31^{st}$ in 2012. N sources were SCB and urea. Four N treatments with 3 replications consisted of control (No N fertilizer), SCB 0.5N + Urea 0.5N (50:50 split application), SCB 1.0N, Urea 1.0N. 100% of N recommendation rate from soil testing was denoted as 1.0N. The subsurface drip line and a tensiometer were installed at 30 cm soil depth. An irrigation was automatically started when the tensiometer reading was -15 kPa. The growth of cucumber at 85 days after transplanting was 5% higher in all N treatment than control. Semi-forcing culture produced more fruit yield than retarding culture. Fruit yields were 62.2, 76.3, 76.4, and 75.1 Mg $ha^{-1}$ for control, SCB 1.0N, Urea 1.0N, and SCB 0.5N + Urea 0.5N, respectively. Although fruit yields were similar under SCB 1.0N, Urea 1.0N, and SCB 0.5N + Urea 0.5N, 176 kg K $ha^{-1}$ can be over applied if cucumber is grown twice a year under SCB 1.0N that may result in K accumulation in soil. N uptake was 172, 209, 213, 207 kg $ha^{-1}$ for control, SCB 1.0N, Urea 1.0N, and SCB 0.5N + Urea 0.5N, respectively. N use efficiency was the highest (37%) at SCB 0.5N + Urea 0.5N under semi-forcing culture. Nitrate-N concentration in soil for all N treatments except control in semi-forcing culture was the highest between 15 and 30 cm soil depth at the 85 days after transplanting and between 0 and 15 cm soil depth after cucumber harvest. These results suggested that SCB 0.5N + Urea 0.5N can be used as an alternative N management for cucumber production in greenhouse if K accumulation is concerned.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.52 no.3
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• pp.311-319
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• 2007

This study was conducted to estimate effects of application of controlled release complex fertilizer with latex coated urea (LCU-complex) on growth and grain quality of rice under direct seeded on dry paddy (DS) and transplanted on flooding paddy (TP). Three types of latex coated urea different nitrogen (N) releasing were LCU40, LCU80 and LCU100. The time of N releasing of LCU formulations in water at both 20 and $30^{\circ}C$ was faster in the order of LCU40, LCU80, LCU blend (LCU40, LCU80 and LCU100 was mixed in ratio of 2:2:1), and LCU100. The number of tillers and dry matter weight were great in order of LCU-complex 100% > LCU-complex80% > urea and plant height was not significant. Grain yields at LCU-complex80% in both DS and TP plot were similar to those of urea application. N recovery of LCU-complex80% and 100% was improved 8 and 6% compared to that of conventional urea split application in DS plot and 9 and 4% in TP. Content of protein of grain at applied LCU-complex was less 0.8% and $0.1{\sim}0.7%$ than that of urea in DS and TP, respectively. Content of amylose and Mg/K ratio in rice grain was not significant. Consequently application of LCU-complex blended types of coated urea different N releasing can be reduced 20% of N without yield reduction and improved grain quality compared with urea application.

• Journal of The Korean Society of Grassland and Forage Science
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• v.25 no.4
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• pp.239-244
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• 2005

This study was conducted to investigate the effect of the planting densities and nitrogen levels on the growth characteristics, dry matter yield and nutritive value of corn for silage in alpine area(altitude 800m a.s.1.) of National Livestock Research Institute from 2001 to 2002. The experiment was arranged in a split plot design with three replications. Main plots consisted of three planting densities, low(67,000 plants/ha), medium(89,000 plants/ha) and high(95,000 plants/ha). Sub plots consisted of three nitrogen levels, 150 kg/ha, 200 kg/ha, and 250 kg/ha. Tassel height of corn was increased with decreasing planting density, and nitrogen level of 200 kg/ha in all main plots. Ear height of corn was decreased with increasing planting density, and 150 kg/ha of three nitrogen levels. But there were no significant differences among treatment in tassel and ear height. Although dry matter ear ratio of whole com was increased with decreasing planting density, there were no significant differences among treatments. But there were significant differences among nitrogen levels(P<0.05). Dry matter yield of com was high with increasing planting density, but there were no significant differences among treatments. And DM yield of corn was significant difference among nitrogen levels(P<0.05). Crude protein content of corn was the highest with high planting density and low nitrogen level. NDF and ADF content of com was the highest with low planting density and nitrogen levels of 200 kg/ha in all main treatments. These results indicate that low planting density(67.000 plants/ha) and nitrogen of 150-200 kg/ha would be the optimum level fur dry matter yield and nutritive value of silage com in alpine area.

• Journal of The Korean Society of Grassland and Forage Science
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• v.6 no.3
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• pp.157-163
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• 1986

Synthesis and accumulation pattern of Weender components in orchardgrass (Dactylis glomerata L.) cv. Potomac and Baraula, perennial ryegrass (Lolium perenne L.) cv. Reveille and Semperweide and meadow fescue (Festuca pratensis Huds.) cv. Cosmos 11 and N.F.G. were studied under different growth environments and cutting managements. The field experiments were conducted as a split plot design with three cutting regimes of 6-7 cuts at grazing stage, 4-5 cuts at silage and 3 cuts at hay stage from 1975 to 1979 in Korea and West Germany. The results obtained are summarized as follows: 1. Air temperature, rainfalls and solar radiation were found to be an important meteorological factors influenced to synthesis and accumulation of Weender components. Under high temperature and strong solar radiation during summer season in Korea, accumulation of crude fiber and cell-wall constituents (NDF) in the plants, as average of all grass species and cutting regimes, were increased to about 30.1% and 48.7% from 27,9% and 42.9% in spring, respectively, while total nonstructural carbohydrates (TNC) were decreased to 1.52% in summer from 4.01% in spring. In West Germany, the concentration of Weeder components showed little seasonal variation. 2. Crude fiber and neutral detergent fiber (NDF) were shown higher concentration in orchardgrass than those of perennial ryegrass and meadow fescue, but N-free extractions and TNC as well as net energy value were less accumulated in orchardgrass. Orchardgrass contained lower net energy contents with 534 StE. 431 StE and 575 StE/kg for Suweon, Cheju and Freising, respectively, as compared with 624 StE (Suweon), 491 StE (Cheju) and 657 StE/kg (Freising) in meadow fescue.

• Journal of The Korean Society of Grassland and Forage Science
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• v.6 no.3
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• pp.145-150
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• 1986

The experiments were conducted to study the influence of growth location and cutting microelements macro-and on managements in temperate grasses in Korea and West Germany from 1975 to 1979. The field trials were designed as split plot with three grass species of Dactylis glomerata L., Lolium perenne L. and Festuca pratensis Huds under three cutting regimes at grazing stage, silage stage and hay stage. The results obtained are summarized as follows: 1. Concentrations of macro-and microelements in temperate grasses showed a different response to growth location and growing season. P concentration in the plants was decreased under hot stress in summer, whereas Mg and Na tended to be increased. The seasonal changes in K and Zn were not significant. 2. Morphological growth stage was to be found as an important factors influenced to mineral components. P and K contents in temperate grasses tended to be decreased as morphological development especially under high temperature in Suweon and Cheju. Ca and Mg were less affected by morphological stage and cutting managements. 3. Mean value of Ca/P ratio in the plants were 1.58, 1.33 and 1.21 for meadow fescue, perennial ryegrass and orchardgrass, respectively. Ca/P ratio in grasses tended to be increased as morphological development. 4. Zn deficiency in the plants occured in all grass species and experimental sites. Mean Zn concentration of the plant were 34.2%, 31.2% and 37.8% for Suweon, Cheju and Taekwalyong, respectivelly. Na deficiency occured in orchardgrass and meadow fescue, especially in taekwalyong. Cool temperature resulted in a decrease of Na absorption and accumulation.

• Restorative Dentistry and Endodontics
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• v.23 no.2
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• pp.561-574
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• 1998

The purposes of this study were to observe the difference in the root canal wall after hand instrumentation or engine-driven Ni-Ti instrumentation under the scanning electron microscope, and to evaluate the apical leakage provided by continuous wave of canal filling technique with or without root canal sealer and smear layer. Twenty recently extracted human maxillary anterior teeth were instrumented with K-type files or engine-driven Ni-Ti files, Quantec series 2000$^{TM}$ and irrigated with 5.25% NaOCl alone or 15% EDT A and final flush of 5.25% NaOCl. After the instrumentation and flushing, teeth were split in half with a knife and a mallet. They were then examined with a scanning electron microscope Forty-four recently extracted human maxillary anterior teeth were divided into four groups with and without smear layer and then warm vertical canal filling using System-B with or without sealer. The extent of leakage was scored after immersion in India ink for 1 week. The results were as follows: 1. No significant difference of smear layer was observed between K-type file-instrumented group and engine-driven Ni-Ti file-instrumented group. 2. A group without smear layer showed significantly less apical leakage than a group with smear layer when sealer was used for the canal filling (p<0.01). 3. There was no significant difference between a group without sealer and smear layer and a group without sealer and with smear layer (p<0.01). 4. In groups without smear layer, a group with sealer showed significantly less apical leakage than a group without sealer (p<0.01). 5. When root canals were irrigated with NaOCl alone, a group with sealer showed significantly less apical leakage than a group without sealer (p<0.01).

• Journal of The Korean Society of Grassland and Forage Science
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• v.21 no.1
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• pp.1-6
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• 2001

This experiment was conducted to evaluated the effect of maturity at harvest on the changes in quality of round baled rye silage at forage experimental field of Grassland and Forage Crops Division, National Livestock Research Institute, RDA, Suwon in 1998. The experimental design was a split-plot design with three replications. The main plots were three different harvest stages : boot, heading and flowering stages, and the subplots were days after ensiling : 1, 2, 3, 5, 10, 30, 45, and 60 days. The wilting period of boot, heading and flowering stages were 1, 0.5 and 0.5 days, respectively. The final pH of rye silage was higher in the order of flowering, boot and heading stages. And pH of flowering stage began to change at early fermentation period, but that of boot and heading stages was delayed 1~2 days. Ammonia-N content of boot stage was highest. and that was increased as fermentation progressed. But Ammonia-N of heading stage was decreased to 30 days. then that was increased after 45 days fermentation. Among fermentation periods, inside temperature of deep place was not affected by external temperature. And that of deep place was increased to 3$0^{\circ}C$ at early fermentation. then decreased as fermentation progressed. However surface temperature was affected by external temperature after 10 days. Acetic acid content was not changed with 5 days by harvest stages, but that of boot stage was increased after 10 days. Butyric acid of boot stage was increased after 5 days. but that of heading stage was increased after 10 days. However lactic acid was increased from 1~2% to 6~8%. Lactic acid bacteria (LAB) of heading and flowering stages were highest at 5 days fermentation, and that of boot stage was highest at 10 days fermentation. The results of this study indicate that fermentation of round baled rye silage occur within 5 days. Therefore, any modification should be applied with an 5 days for high quality of round baled rye silage.