• Journal of Korea Water Resources Association
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• v.53 no.11
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• pp.999-1013
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• 2020

Weather modification research has been actively performed worldwide, but a technology that can more quantitatively prove the research effects are needed. In this study, the seeding effect, the efficiency of precipitation enhancement in weather modification experiment, was verified using the radar data. Also, the effects of seeding material on hydrometeor change was analyzed. For this, radar data, weather conditions, and numerical simulation data for diffusion were applied. First, a method to analyze the seeding effect in three steps was proposed: before seeding, during seeding, and after seeding. The proposed method was applied to three cases of weather modification experiments conducted in Gangwon-do and the West Sea regions. As a result, when there is no natural precipitation, the radar reflectivity detected in the area where precipitation change is expected was determined as the seeding effect. When natural precipitation occurs, the seeding effect was determined by excluding the effect of natural precipitation from the maximum reflectivity detected. For the application results, it was found that the precipitation intensity increased by 0.1 mm/h through the seeding effect. In addition, it was confirmed that ice crystals, supercooled water droplets, and mixed-phase precipitation were distributed in the seeding cloud. The results of these weather modification research can be used to secure water resources as well as for future study of cloud physics.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.6
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• pp.699-705
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• 1997

This experiment was conducted to find out an optimum direct seeding date for rice in the southern alpine area of Korea as direct seeding method being considered as the most labor-saving method. A cultivar which was sprouted, Keumobyeo, was sown on the surface of flooded paddy from April 25 to May 15 with 5-day interval. The growth characters such plant height, tiller numbers, yield and its components as well as air temperatures were observed. Earlier sowing showed longer plant height and greater tillers than later sowing. Accumulated temperatures in the different growth stages varied from 1,010 to 1,052$^{\circ}C$ during the period from seeding date to maximum tillering stage, and from 1,785 to 1,846$^{\circ}C$ during the period from seeding to heading dates. The growth of rice sown up to May 5 showed comparatively good when compared to that of machine-transplanted rice, even though the grain yield was not competitive to that of machine-transplanted rice. Highly negative correlation coefficients were found between accumulated temperature during the period of first 30 days after seeding dates and the number of panicles, the number of spikelets per square meter, and grain yield. Regression equation between direct seeding date(X) and yield(Y;MT /ha) was $\hat{Y}$ =3.80990＋0.06207X-0.00174 $X^2$($R^2$=0.704), from which optimum seeding date for direct seeding method in alpine area was estimated to be on April 25 to May 1.

• Journal of The Korean Society of Grassland and Forage Science
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• v.39 no.3
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• pp.178-184
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• 2019

The objective of this study was to evaluate the dry matter yield of (DMY) of Italian ryegrass (IRG) forage crop based on two seeding date (September 25 and October 2) in 2017 and 2018, and evaluation of the potential reason of DMY reduction in IRG cultivars grown at Chuncheon, South Korea. Three cultivars of IRG including Kowinearly, Kowinmaster and Hwasan 104 were used in this experiment. The experimental field was designed as a split-split-plot arrangement. The cultivars were harvested on April 26 before the heading stage of both years. In this study, no significant effect (p>0.05) of seeding date has been found on the DMY, whereas the cultivars and year showed a significant effect on the DMY (p<0.05). Except September 25 of 2017, Hwasan 104 indicated significantly lower (p<0.05) DMY than Kowinearly and Kowinmaster in all seeding periods. Though no significant difference (p>0.05) was observed for the DMY between the two seeding dates in 2018, but the DMY was significantly lower (p<0.05) than that of 2017. Lower crude protein (CP) content of Kowinearly was observed on the seeding date of October 2 of 2017, and also in both seeding dates on 2018 (p<0.05). No significant difference (p>0.05) was observed in acid detergent fiber (ADF) between the cultivars on both seeding dates and years. Similarly, no significant difference (p>0.05) was found in neutral detergent fiber (NDF) between the cultivars in 2017. However, Kowinearly showed higher NDF content as compared to Kowinmaster and Hwasan 104 on both seeding dates and years. The seeding date has no significant difference (p>0.05). Thus, considering the extent of DMY in both years, the mean minimum temperature during winter season could be the limiting factor for the DMY of IRG cultivars. However, based on this study, the seeding dates of September 25 and October 2 have no potential effect on the DMY. Thus, on the basis of the current DMY and forge quality parameters, the cultivation Kowinmaster is recommended in Chuncheon.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.36 no.2
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• pp.154-159
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• 1991

A field experiment was conducted to know the feasibility of direct-seeded rice. Dry seeds of a Japonica type rice variety, Donghaebyeo, was sown from May 10 to June 20 at the 10-day intervals. The number of days from seeding to emergence decreased as planting date delayed; 13, 12, 10, 9, and 7 days at May 10, May 20. May 30. and June 10 seedings, respectively. The number of maximum tillers per ㎡ was about 700-800 at all the seeding dates and effective tiller ratio ranged 40-45%. The number of days from seeding to heading decreased as seeding date delayed; from 97 days at May 10 planting to 71 days at June 20 planting. The cumulative effective temperature (mean air temperature-15$^{\circ}C$) from seeding to heading was fairly constant having 870$^{\circ}C$ with 2.3% C.V. The number of panicles per unit area at June 10 planting was higher than that of other planting dates. Panicle length and the number of spikelets per panicle tended to decrease as seeding date delayed. The number of spikelets per unit area, 1000-grain weight, and grain yield were similar among the seeding dates except June 20 seeding. At the June 20 seeding the number of spikelets and grain yield were much lower, but 1000-grain weight was higher compared with other seeding dates. Grain fertility and percent ripened grains was similar among all seeding dates.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.37 no.6
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• pp.534-540
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• 1992

Climatic condition and seeding depth affect the seedling stand and early growth in the direct-seeded rice cultivation on dry soil. This experiment was conducted to elucidate the effects of the day /night temperatures and the seeding depths on the seedling emergence and mesocotyl elongation of rice seed. Three combinations of the day/night temperatures(25/2$0^{\circ}C$ 20/15$^{\circ}C$ and 20/1$0^{\circ}C$) were employed with seeding depths 1, 3, 5 and 7cm at the Phytotron of the Crop Experiment Station in 1991. It appeared that seedling emergence ratio increased and days to seedling emergence decreased in the high temperature (25/2$0^{\circ}C$) and the deep seeding depth (5 and 7cm) condition. The seedling emergence ratio did not. show the, difference up . to the seeding depths of 3cm and below, but the ratio decreased from the seeding depths of 5cm and above. Plant height and leaf number were almost the same up to the depths of 3cm at 30 days after seeding, but those of the seeding depths of 5cm and 7cm were remarkably reduced in all temperature combinations. Mesocotyl and lower internode elongation were seen in the high temperature(25/2$0^{\circ}C$) with the seeding depths of 5cm and 7cm. In the seeding depth of 6cm, of the tested varieties, Tamjinbyeo and Odaebyeo showed the highest emergence ratio. Generally, leaves of all tested varieties appeared approximately in the soil depth of 3cm, so the reasonable seeding depth will be around 3cm in the direct-seeded cultivation on dry soil.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.spc1
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• pp.47-51
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• 2006

This study was conducted to establish the optimum seeding rate in different soil salinity level for yield stability of broadcasting on flooded paddy surface to the reclaimed saline land of south-western part at Gyehwado substation of the Honam Agricultural Research institute in $2003{\sim}2004$. Soeganbyeo was tested in the Munpo series (fine sand loam) the results obtained is as follows: As seeding rate was higher, the number of seeding stand was increased and the number of seeding stands in the low salinity field is sharply increased than those of the medium salinity field. The length of culm in medium salinity field tends to be shorter than that of the low salinity field and as seeding rate was increased, the lodging is severe. The milled rice yield was increased as up to 9 kg/10a in low and medium salinity soil. Complete rice was no significantly increased over 5 kg/10a seeding rate in low salinity field and over 7 kg/10a seeding rate in medium salinity field. Considering the yield of milled and complete rice, seeding stand and lodging, The proper seeding rate is $5{\sim}7kg/10a$ in low salinity and $7{\sim}9kg/10a$ in medium salinity for broadcasting on flooded paddy surface at the reclaimed saline land of southwestern part.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.4
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• pp.378-383
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• 1997

Bird damages are often occurred at the seeding and seedling stages of crops. What the bird damage is preventing from the seeding and seedling of rice in the paddy would be very important to get high yield. Methiocarb was formulated as a bird repellent of crop seeding and seedling. Its effects on the seedling growth, related to the chemical injuries and the bird damages, were examined at the seeding and seedling growth stages of Anjungbyeo(Oryza sativa L.) with different types and amounts of methiocarb treatment in both pot and field experiments. In the pot experiment, bird damages were not occurred at all treatments of methiocarb, while bird damages were occurred at the control; 30, 85, and 100％ of damages at 5, 10, and 15 days after seeding, respectively. The ratio of seedling stand was not significantly different among all of treatments, methiocarb, methiocarb＋thiram, and control. However, the plant height and the number of seedling leaves at 15 days after seeding was shortened and lowered statistically more at treatment of methiocarb 15g than those of methiocarb 10g and control. The plant height at 35 days after seeding, showing the recovery degrees of chemical injuries, was significantly lowered in treatment of methiocarb＋thiram 15g, whereas the plant height of methiocarb FS 15g was not significantly differed from that of the control. In the field study, the bird damages were significantly reduced in treatment of methiocarb compared to that of the control. The plant height and the number of leaves at 25 days after seeding were not differed statistically among all of treatments. The chemical injuries were occurred in all treatments of methiocarb at 10 days after seeding, while they were not shown at 20 days after seeding.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.32 no.3
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• pp.287-293
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• 1987

To find out the effects of seed maturity and seeding rate of two planting times on the seed emergence and silage and seed yields of rye, a local variety 'Paldanghomir' harvested 30 and 45 days after heading(DAH) were planted at five seeding rates on October(optimum) and November(late) in 1985. At the optimum planting, number of seedlings per unit area and number of tillers per plant were affected by seeding rate, but not by the seed maturities. However, at the late planting, number of seedlings per unit area and number of tillers per plant wer higher in the seed harvested 45 DAH, and they were not correlated with seeding rate in both seeds harvested 30 and 45 DAH. Heading date was 2 or 3 days earlier in the seeds harvested 45 DAH in both planting times. Silage yield was higher at the optimum planting and increased as seeding rate increased in both planting times. Number of spike and 1000~seed weight were higher at the optimum planting than late planting and higher in the seed harvested 45 DAH than 30 DAH in late planting, but were not different among seeding rates. Seed yield at optimum planting showed no difference between seed maturities and among seeding rates, and recommandable seeding rate was 600 seeds per $m^2$. At late planting the seed yield of the seed harvested 45 DAH in the seeding rate over 750 seeds per $m^2$ approached to the yield of the optimum planting. The seed harvested 30 DAH was unstable because of extremely low emergence rate and yield even at the higher seeding rate in late planting. planting.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.59 no.3
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• pp.375-384
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• 2014

Kenaf (Hibiscus cannabinus L.) was recognized as a potential source of forage. But the domestic cultivation techniques are not set standards yet. So we tested the basic culture techniques during 2012~2013 for getting a high yield and good grade forage production system. The best seeding method for mechanized planting (corn planter used) was hill seeding with $20{\times}20cm$ seeding distance. When we treated hill seeding with $20{\times}20cm$, the yield what we could get was 13,641 kg/10a and it was 32% more than that of conventional practice hill seeding with $20{\times}30cm$ seeding distance. The proper seeding date for getting high yield was May 1. In May 1, the yield per 10a was reached 13,423 kg, and it was 30% more than that of seeding at May 30. More over the crude protein content which was important factor for determinating forage nutritive value was 12.7% and it was higher 1.8% (relatively 16.5% high) than that of May 30 seeding. The most effective herbicide for kenaf was Fluazipof-p-butyl. It's herbicidal rate was 97% and phyto-toxicity was less than 5%. Regional adaptability for Jeollabuk-Do including Imsil Gun, Kochang Gun and Sunchang Gun were identified that the stable cultivation were possible in these area with average yield 12,400 kg/10a and it was about 1.7 times as compared to corn harvest.

• Korean Journal of Materials Research
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• v.6 no.7
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• pp.723-732
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• 1996

Cu films were deposited by chemical wapor deposition on the as-received substrates (TiN/Si) and three kinds of Cu-seeded substrates (Cu/TiN/Si) which had seeding layer in the thick ness of 5 ${\AA}$ and 130 ${\AA}$ coated by ICB(Ionized Cluster Beam) method. The effect of Cu seeding layers on the growth rate, crystallinity, grain size uniformity and film adhesion strength of final CVD-Cu films was investigated by scanning eletron microscopy(SEM), X-ray diffractometry and scratch test. The growth rate was found to incresase somewhat in the case of ICB-seeding. The XRD patterns of the Cu films on the as-received substrate and ICB Cu-seeded substrates exhibited the diffraction peaks corresponding to FCC phase, but the peak intensity ratio($I_{111}/I_{200}$) of Cu films deposited on the ICB Cu-seeded substrates increased compared with that of Cu films on the as-received substrate. The resistivity of final Cu film on 40 ${\AA}$ seeded substrate was observed as the lowest value, 2.42 $\mu\Omega\cdot$cm compared with other Cu films. In adhesion test, as the seeding thickness increased from zero to 130 ${\AA}$, the adhesion strength increased from 21N to 27N.