• Journal of The Korean Society of Grassland and Forage Science
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• v.29 no.4
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• pp.321-328
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• 2009

This experiment was carried out to investigate the effect of cultivar and seeding date on the winter survival rate, quality and DM yield of Italian ryegrass on paddy field for three years in Suwon. Seeding started from 30th Sep. 2003. at intervals of five days and finished 20th Oct. New varieties of Italian ryegrass used in this experiment were "Kospeed", "Kowinmaster" and "Hwasan 101". The winter survival average rate of 5th Oct. seeding plot was 89.8% and it decreased with delayed seeding date. The heading date of "Kospeed" was 7th~13rd May, "Kowinmaster" was 16th May, but "Hwasan 101 ho" didn't show heading until 17th May. Dry matter (DM) yields of 30th Sep. seeding plot were Kospeed 7,909kg/ha, Kowinmaster 6,398 kg/ha and Hwasan 101 ho 5,204 kg/ha. DM yield was decreased with delayed seeding date. Total digestible nutrient (TDN) yield was also decreased with delayed seeding date. Crude protein (CP) content was the highest in Kospeed. seeding plot as 18.3% and in vitro dry matter digestibility (IVDMD) was not showed significant difference among seeding dates.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.54 no.4
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• pp.407-415
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• 2009

To investigate the effects of seeding date, nursery days and plug cell size on seedling growth and quality of waxy corn. This study was carried out in the field of the National Institute of Crop Science in 2007. Varieties used were two waxy corn hybrids cvs. Chalok# 1 and Chalok# 4. The plant height, number of leaves and dry weight of waxy corn seedlings were significantly affected by seeding dates and plug cell size, while no differences between varieties. The growth of seedlings was faster in March 14 seeding than in May 8 and July 4 seedings. Based on plant height, March 14 seeding, May 8 seeding and July 3 seeding reached suitable size for transplanting after 30 days (21.6cm), 15 days (25.5~26.9cm) and 10 days (21.6~24.0cm) in the nursery, respectively. Seedlings of March 14 seedling and May 8 and July 3 seeding reached suitable number of leaves i,e. 2~3 leaves, 15~20 days after seeding on March 14 and 10 days after seeding on May 8 and July 3. Dry weights of 30 days seedling for March 14 seeding, 20 days seedling for May 8 seeding and 15 days seedling for July 3 seeding were 0.43g, 0.57~0.67g and 0.53g, respectively, and the dry weight of seedlings increased by 2~3 folds at the later nursery days. The suitable nursery days of waxy corn were 20 days on March 14 seeding and 10~15 days on May 8 or July 3 seeding.

• Journal of The Korean Society of Grassland and Forage Science
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• v.32 no.3
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• pp.209-220
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• 2012

Most oats are used for livestock feed in the world. This experiment was conducted at Iksan city of Korea from 2007 to 2008. The objective of this study was to select eminent oat (Avena sativa L.) cultivars with high-yielding and a quality for forage adaptable in each planting seasons. Experimental design was split-plot design with three replications. A split plot design was used with seeding date on the main plots and other treatments fully randomized in sub-plots. A factorial arrangement of treatments included three different ecotypes cultivars, winter type (Sanmhan, Donghan and Chohan), summer type (High-speed, Darkhorse, and Swan), and naked oats near to spring type (Daeyang, Choyang, and Sunyang) and twelve seeding dates (twice a month from March to November). Plant height, dry matter yield, and percent TDN was significantly affected by seeding dates, cultivars, and the interaction of cultivars ${\times}$ seeding dates. There was a decrease in plant height, dry matter yield, and percent total digestible nutrients (TDN) as seeding was delayed from early March to late June and it also from early September to early November. The winter type oat cultivars such as Samhan, Donghan, and Chohan adapted to fall seeding and early summer harvest, while summer type cultivars such as High-speed, Darkhorse, and Swan showed high productivity either to summer seeding and mid-fall harvest or to spring seeding and early summer harvest. Naked type cultivars, Choyang and Daeyang, showed high forage yield by spring and summer seeding except for fall seeding because of cold damage. Summer type oat cultivars such as High-speed, Darkhorse, and Swan can supplement high forage production in spring. TDN yield showd the most at seeding in October 10 (780 kg $10a^{-1}$), followed at seeding in March 23 (627 kg $10a^{-1}$).

• Journal of The Korean Society of Grassland and Forage Science
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• v.12 no.1
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• pp.33-40
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• 1992

This experiment was carried out to determine the effects of seeding rates and nitrogen fertilization levels on the yield. carbohydrate reserves in stubble and stand reduction of sorghum-sudangrass hybrid (Sorghum bie%r (L.) Moench) in 1983 on the Experimental Livestock Farm, College of Agriculture, Seoul National University in Suwon. The results of this experiment are summarized as follows: I. There was no significant difference in forage yield among three seeding rates(20, 40. and 80kgjha), but there was a significant difference(P <.0 I) in forage yield among three N fertilization levels(O, I 50. and 300kgjha). High nitrogen plot showed the highest dry matter yield. 2. Carbohydrate reserves were influenced not only by seeding rates, but also by nitrogen fertilization levels at first cut(P < .05). At second harvest, no treatments affect the carbohydrate reserves. 3. Only the seeding rates affect the stand reduction at first harvest. But the mortality was influenced by seeding rates and N fertilization levels(P < .05). The high seeding rates caused the high mortality. 4. According to the results obtained from this study, it is suggested that the seeding rate of 40 kgjha and nitrogen fertilization of 300kgjha would be recommendable for maximum forage yield and good performance where sorghum-sudangrass hybrids are broadcasted for summer forage production.

• Journal of the Korean earth science society
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• v.36 no.4
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• pp.301-314
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• 2015

The purpose of this study was to investigate the impact of ground-based glaciogenic seeding on orographic clouds in the Daegwallyeong area on 13 March, 2013. The experiments was conducted by releasing silver iodide (AgI) under following conditions: surface temperature below $-4^{\circ}C$, wind direction between 45 and $130^{\circ}$, and wind speed less than $5ms^{-1}$. Two seeding rates, $38gh^{-1}$ (SR1) and $113gh^{-1}$ (SR2), were tested to obtain an appropriate AgI ratio for snowfall enhancement in the Daegwallyeong area. Numerical simulations were carried out by using the WRF (Weather Research and Forecast) model with AgI point-source module which predicted dispersion fields of AgI particles. The results indicated that the target orographic clouds contained adequate amount of supercooled liquid water and that the dispersion of AgI particles tended to move along the prevailing wind direction. To validate the seeding effects, the observation data from FM-120 and MPS as well as PARSIVEL disdrometer were analyzed. In this case study, glaciogenic seeding significantly increased the concentration of small ice particles below 1 mm in diameter. The observation results suggest that SR1 seeding be reasonable to use the ground-based seeding in the Daegwallyeong area.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.53 no.3
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• pp.273-278
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• 2008

This study set out to investigate the changes to the growth, yield, and flavonoid contents of mungbean according to different seeding times from mid May to mid July in the southern region of Korea. Days to first flowering, days to first maturing, and cultivation period were shorter at later seeding time than earlier seeding time. But later the seeding time was, days from first maturing to first harvesting, days required between harvesting increased. Number of pods at first harvesting and yield of mungbean were highest when seeded at late June, showing increase in yield 14% more than at early June as standard seeding time. However number of seeds per pod and 1,000-seed weight at first harvesting were highest when seeded at mid July. The number of harvesting was smallest at two times when seeded at June or mid July. The contents of average vitexin and isovitexin in mungbean were highest in the order of mid July, late June, and mid May. In particular, their contents reached its highest point in the seeds of the second harvest. Considering the results of the cultivation period, yield, harvesting times, vitexin and isovitexin contents, the proper seeding time of mungbeans in the southern region of Korea will be from late June to mid July.

• Journal of The Korean Society of Grassland and Forage Science
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• v.29 no.1
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• pp.25-30
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• 2009

This experiment was conducted to evaluate the effect of direct seeding time on the yield and quality of whole crop rice at experimental field of Grassland and Forages Research Center, National Institute of Animal Science, RDA from 2005 to 2006. Whole crop rice variety, "Namil", was direct seeded at five different calender date (25 April, 10 May, 25 May, 4 June and transplanted at 25 May). The heading date was delayed at late seeding date. Crude protein (CP) was increased with delayed direct seeding date. The content of ADF (acid detergent fiber) and NDF(neutral detergent fiber) increased with delayed seeding date. The average TDN (total digestible nutrient) content was 61.5% and it also decreased with delayed direct seeding date. The highest DM (dry matter) yield was seeded at 25 April and transplanted at 25 May, 15,185 and 15,815 kg/ha, respectively. Although delayed direct seeding date decrease the DM yield, mid-May will be recommendable as proper direct seeding date.

• Journal of Practical Agriculture & Fisheries Research
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• v.7 no.1
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• pp.35-46
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• 2005

This research was conducted to improve and establish Bokto direct seeding technology use of silicate in rice. Bokto direct seeding technology has recently released to alternative new method for transplanting method of the rice plant. In recent rice production has serious problem due to higher cost and labor shortage in Korea. In particular rice has been faced on open market to internationally due to WTO, FTA agreement etc. Thus rice growers in Korea have been more concentrated on cost reduction using by direct seeding technology such as dry seeding and water seeding while those methods have severe constraints like poor seedling, more weed occurrence, lodging and poor grain quality. In recent a new technology for improvement of these problem has released to farmer's field and proven to alternative rice growing technology of transplanting. In this technology there was additional application of silicate which has known as soil improvement and this research was obtained in the following results. At the application of silicate, sand, and soil there was high in seedling establishment by 90~100% in pot experiment but there was 55.0% seedling stand of the untreated control. Under dry condition seedling stand was 0% at the untreated control while 65~100% high in application of silicate, sand, and soil. Meanwhile, under rainy condition untreated control there was 85% of seedling stand but soil application was 20% of seedling establishment due to blocking of oxygen and physical soil blockage.

• Journal of The Korean Society of Grassland and Forage Science
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• v.4 no.1
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• pp.51-61
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• 1983

This experiment was carried out to determine the effects of different seeding rates of Italian ryegrass (Lolium multiflorum) and cutting frequency on the dry matter yield botanical composition of pasture mixtures in first harvest year. The experimental design was a split-plot design with three replication. The main plots were two seeding rates of Italian ryegrass at 0.3 and 1.0kg per 10a and the sub-plots were 3, 4, and 5 cutting frequency. The experiment was undertaken over a period 12 months from September 1981 to August 1982. The results obtained are summarized as follows: 1. The different seeding rates of Italian ryegrass had no effect on total day matter yield. 2. Over the experimental period, the total dry matter yield of pasture mixtures was increased with increasing the cutting frequency, but there was no significant. 3. It was found that dry matter yield of weeds clearly decreased with the high seeding rate of Italian ryegrass over the experimental period. 4. The high seeding rate of Italian ryegrass showed the trend toward the high yield of Italian ryegrass, and the low yield of orchardgrass and ladino clover. 5. At the early stage of the experiment, the botanical compositions of orchardgrass and ladino clover were decreased with the high seeding rate of Italian ryegrass. But at the final stage they were not influenced by the seeding rates of Italian ryegrass. From the above results it is suggested that the high seeding rate of Italian ryegrass give a good effect on the early forage yield and weed control, and the high cutting frequency maintain desirable botancial composition of orchardgrass and ladino clover in the pasture mixtures with Italian ryegrass.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.46 no.3
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• pp.221-228
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• 2001

This study was carried out to investigate the effect of germination condition and drying temperature on growth and physicochemical properties of brown rice. Three brown rice seeds of Ilpumbyeo, Dasanbyeo and Heugjinjubyeo were stored at room temperature for six weeks to test the time-sequence germination viability. Relatively stable germination ratio was maintained until 2 weeks after storage. However, 3 weeks after storage, germination ratio of brown rice seeds started to decrease rapidly and their germination ratio was lower than 80%. For this reason, brown rice was recommended for seeding within 2 weeks after hulling. During the initial 5 days, germination ratio of 24 hours pre-soaking brown rice was higher about 2-3% than that of non-soaking brown rice. The $25^{\circ}C$ was considered as the most favorable temperature for brown rice germination, because of the high germination ratio and desirable coleoptile growth of the brown rice, and little seed rotting symptoms. The scanning electron micrographs showed the structural differences between hot-air dried and freeze dried germinated-brown rice kernel. In the freeze dried germinated-brown rice, seed coat (pericarp, tegmen and aleurone layer) was mechanically disrupted from the endosperm, and many cleavages were observed among starch storing cells and starch granules. The endosperm of freeze-dried brown rice kernels formed the sponge-like structures and showed the fragile traits. For this reason, hot-air drying is considered as more suitable method than freeze drying for germinated-brown rice. The crude protein and amylose contents were slightly changed, but there were no significant differences during the germination period. Crude fiber content was decreased, but crude Int and total amino acid contents were increased as seeding days increased. A rapid increase in $\alpha$-amylase activities of germinating brown rice was observed at S days after seeding, and $\alpha$-amylase activities were decreased from 8 days after seeding. Total free sugar contents were decreased during the germination period. There was continuous decline in the contents of sucrose and glucose until 8 days after seeding, but fructose and maltose content were gradually increased from the 5 days after seeding.