• Korean Journal of Agricultural and Forest Meteorology
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• v.2 no.4
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• pp.183-189
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• 2000

This study was carried out to analyze ecophysiological responses for seedling of Quercus serrata, Quercus mongolica and Quercus variabilis that are the typical species of deciduous broadleaved forests in Korea. And executed experiments in the climatic control room to provide necessary information to ecological forest management and methods of natural regeneration through the analysis of seedling responses. The details of experimental analysis were growth processes of 4 months after seeding that vary with the condition of three light intensity[relative light intensity(RLI) 8%, 20%, 52%] and three soil moisture[water suction(WS) Ψ=100 hPa, Ψ=280 hPa, Ψ=330 hPa] gradient, growth factors after harvesting and the nutrition condition of leaves. The results of this study are followings: 1) Early growth was prosperous after germination for the species which have more weight of acorn. 2) The formation of lammas shoot was favourable with Q. variabilis and Q. mongolica. And the rate of the occurrence was the highest in the RLI 20%, and it was remarkably reduced in the RLI 8%. 3) As the height growth of seedling of all 3 species were greater in the RLI 20% and 8% than that of the RLI 52%, they showed strong shade tolerance. 4) The increase of light intensity promoted the diameter at root collar growth, and development of main and lateral roots with all 3 species. 5) It showed that the increase of light intensity in the experimental radiation condition raised special leaf area weight(mg/cm$^2$) and leaf area productivity(mg/cm$^2$). Consequently, these resulted in the increase of leaf thickness and total dry biomass per the unit area of leaf. 6) As the increase of light intensity, the minerals contents of leaves such as N, P and K were lowered, and the increase of soil moisture resulted in the increase of P, K, Ca and Mg.

• Korean Journal of Soil Science and Fertilizer
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• v.35 no.4
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• pp.216-222
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• 2002

Field experiments were conducted to investigate the effect of various cultural practices on methane($CH_4$) emission in tillage and no-tillage practice in a clayey paddy soil from 1998 to 2000. The factors evaluated in tillage and no-tillage methods were types of nitrogen fertilizers, application method of chemical fertilizers, rice straw application and cultivation method. Of the nitrogen fertilizers, the amount of $CH_4$ emission in ammonium sulfate plot was the lowest, regardless of tillage and the application method. 26.4~41.1% of reduction by ammonium sulfate compared with urea. But in no-tillage which have problem of poor rice yield than tillage, coated urea was more effective nitrogen fertilizer because that showed similar $CH_4$ emission and highest rice yield at 80% of dosage of nitrogen. No-tillage plot emitted lower $CH_4$ than tillage plot where the fertilizers were incorporated. On the contrary, no-tillage plot showed a little higher $CH_4$ emission compared with tillage plot for the surface application. When rice straw was applied, no-tillage practice reduced methane emission by 26.6% compared with tillage practice, but showing a little difference of 10.7% in no application. With cultivation method, no-tillage practice reduced methane emission 26.6% compared with tillage for the 30-d-old seedling transplanting. But for the dry direct seeding practice, no-tillage was a less effective because considerable amounts of rice straw incorporated by tillage were more decomposed aerobically in the soil and emitted as $CO_2$ to the atmosphere with flooding in no-tillage soil.

• Korean Journal of Organic Agriculture
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• v.23 no.3
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• pp.549-565
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• 2015

This study was conducted to investigate the growth characteristics and functional materials of baby vegetables as affected by different LEDs and luminous intensity at Anseongsi, Gyeonggi Province, in 2014. Test crops were beet, chicory, spinach, red leaf lettuce, crown daisy and red mustard purchased from the seed company of Dongbu Hannong and Jinheung. Growth characteristics were measured and the content of functional materials was analyzed 40 days after seeding at plug plate. Treatment of Red+Blue (4:1) at $150{\mu}mol\;m^{-2}s^{-1}$ luminous intensity showed the highest number of leaves in five baby vegetables of beet, chicory, red leaf lettuce, crown daisy and red mustard. The highest shoot length of chicory, spinach, red leaf lettuce, crown daisy and red mustard was obtained from the treatment of Red+Blue (4:1) at $150{\mu}mol\;m^{-2}s^{-1}$ luminous intensity. Fresh weight and dry weight of all six baby vegetables were the highest in treatment of Red+Blue (4:1) at $150{\mu}mol\;m^{-2}s^{-1}$ luminous intensity. Content of chlorophyll a and chlorophyll b of spinach, red leaf lettuce and red mustard showed the highest in Fluorescent lamp at $150{\mu}mol\;m^{-2}s^{-1}$ luminous intensity whereas other crops did not show definite trend under different LEDs lights and luminous intensity. The highest total content of anthocyanins and polyphenol were obtained from the treatment of Red+Blue (4:1) at $150{\mu}mol\;m^{-2}s^{-1}$ luminous intensity in all six baby vegetables. Free radical scavenging activity was highest in all six vegetable crops at $150{\mu}mol\;m^{-2}s^{-1}$ luminous intensity, but it was not different significantly between LEDs. As a result, the growth and the content of functional material of baby vegetables are generally to be increased in Red+Blue (4:1) at $150{\mu}mol\;m^{-2}s^{-1}$ luminous intensity. Mixed light of Red+Blue is thought to give good effect on the growth and the content of functional material in baby vegetable crops. Because there are many differences in regard of LED lights, crop varieties, cultivation and experimental methods in their impact on the growth and functional materials of baby vegetables among researchers, it is considered that a more precise studies are needed for the crop responses to LED light and luminous intensity.

• Journal of The Korean Society of Grassland and Forage Science
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• v.38 no.4
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• pp.266-272
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• 2018

In this study, we created grassland establishment(paddock No.39), grassland improvement(Paddock No.44), and tall fescue seeding(paddock No.64), and the rate botanical composition, DM yield, nutritive value were examined through 2016 to 2017. The rate of botanical composition was 81% in 2016, 75% in 2017, up to 21% higher than No.39 67%, 60%, No.44 58% and 54%. The annual average DM yield was the highest at 13,234kg/ha in the district, followed by No.39, No.44, followed by 10,636kg/ha and 10,235kg/ha, respectively. The crude protein content was the highest at No.39 12.16%, with No.44 and No.64 showing 10.7%, respectively. NDF content (average for two years) was 55.90% in No.44 and No.39, slightly lower than 58.42% and 57.00%, respectively. The two-year ADF average content was 31.07% for the same trend as the NDF capacity in the No.44, below 31.71% and 32.65%, respectively. To sum up the results, Although there was a high level of incentive sowing plot(No.39) in nutritive value, considering the botanical composition and productivity of the pasture, it is also deemed desirable to have a tall fescue plot(No.64).

• Journal of The Korean Society of Grassland and Forage Science
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• v.40 no.4
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• pp.221-226
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• 2020

This experiment was conducted to compare the seed productivity of the Italian ryegrass(Lolium multiflorum Lam.) varieties sown in the spring in Gangwon region. The experiment was randomized block design with three replications. The Experimental field was located in alpine areas of about 600 m above sea level in Gangwon province. The tested Italian Ryegrass varieties were 'Greenfarm', 'Greencall' and 'Kowinearly' developed by National Institute of Animal Science, RDA. Italian Ryegrass varieties were sown on March 26, 2020, and the harvest was on the 60th day of mean heading date, July 2. The heading date of Kowinearly was May 8, but Greenfarm and Greencall was May 4. The plant length was the largest in the Kowinearly variety. However, the Kowinearly suffered severe lodging. There was no significant difference in the length of spike among varieties, and the number of seeds per spike was the lowest in Greenfarm at 118.5 seed/spike. As for the seed weight per spike, the Greenfarm variety was significantly lower at 0.56 g/spike, but the 1,000 seed weight was the heaviest in the Greenfarm at 2.5g.. The number of spike per unit area was the highest in Greenfarm at 906/㎡. The dry matter content of seeds was the highest in Greenfarm at 54.3%, and for straw, Kowinearly was the highest at 35.3%. Seed productivity was not significant among varieties, and the average was 1,493 kg/ha. The yield of straw after seed production was also not significant among varieties (P>0.05), and the average was 3,172 kg/ha. From the above results, the production of Italian ryegrass seeds through spring sowing in the Gangwon region is not much than autumn seeding, requiring the input of various technologies to increase productivity in the future, and it is desirable to determine the production cost through economic analysis was judged.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.41 no.4
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• pp.489-495
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• 1996

Seedling emergences of four rice varieties (Dongjinbyeo, Dadajo, Galsaekggarak-sharebyeo, and Italiconaverneco) and three barnyardgrass species(Echjnochloa oryzjcola, E. crus-gali var. crus gali E. crus-gali var. praticola) were evaluated in relation to soil strength. Soil strength was varied by compressing the entire volume of soil with a hydraulic jack so as to be 0.5, 1, 2, 3, 6kg /$\textrm{cm}^2$. Soil strength was measured with a penetrometer (Yamanaka type) and soil covering above the seed was 4cm deep. Experiments were conducted at two air temperature conditions of 17 and $25^{\circ}C$. At a soil strength of up to 2kg/$\textrm{cm}^2$, little or no decrease in seedling emergence occurred in all rice varieties and barnyardgrasses tested. Above that value, seedling emergence decreased progressively as the soil strength increased. The degree of decrease was greatest in Dongjinbyeo and smallest in Dadajo among tested rice varieties, and greatest in Echinochloa oryzicola among barnyardgrasses, being greater in barnyardgrasses than rice. Seedling emergence was delayed almost linearly as the soil strength increased. The delay was greatest in Dongjinbyeo among rice varieties and in Echinochloa oryzicola among barnyardgrasses. Mesocotyl length increased as soil strength increased up to 2 to 3kg / $\textrm{cm}^2$ in Dongjinbyeo and Dadajo in 17$^{\circ}C$ and $25^{\circ}C$, and up to 6kg/$\textrm{cm}^2$ in Galsaekggaraksharebyeo and Italiconaverneco in $25^{\circ}C$. Dongjinbyeo showed the least elongation of mesocotyl among rice varieties in any soil strength. The total length of mesotyl, first internode and incomplete leaf showed little variation with soil strength. The total length was longer than the 4cm covering depth in other varieties except Dongjinbyeo. This might have caused the lower emergence rate in Dongjinbyeo than other varieties in higher soil strength.

• Journal of The Korean Society of Grassland and Forage Science
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• v.43 no.4
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• pp.216-224
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• 2023

Since maize (Zea mays L.) originated in central and south America, it requires warm climate conditions throughout its growing season. Growth halts when night-time temperatures drop below 10℃, and the plant may die if temperature reach -1.7℃. Thus, temperature should be maintained between 10 and 30℃ from seeding to maturity. The germination temperature for maize should be at least 8-11℃, whit an optimal range 32-34℃. Since temperature significantly affects the germination rate and period, it plays a crucial role in maize growth. In this study, we evaluated the quantity and feed value of 11 major varieties to determine those best suited for maize cultivation as feed in higher latitude, specifically in Democratic People's of Republic of Korea, below 38 degrees north. A cultivation test was also conducted in Suwon in Republic of Korea, to assess adaptability in areas south of Mt. Suyang. Among the varieties tested, Shinhwangok2 reached silking the fastest, in 65 days, while Gwangpyeongok took the longest at 75 days. The stem length of all varieties exceeded 230 cm. Gwangpyeongok had the tallest stems, while Daanok and Shinhwangok2ho displayed the highest ear ratios. Dacheongok presented the highest values in both dry matter and TDN quantity, with 31,420 kg/ha and 21,66 kg/ha respectively. Pyeonggangok had the highest crude protein content at 8.0%. TDN (%) ranged from 57-68%, with Hwangdaok reaching up to 68%. Based on these findings, Dacheongok and Pyeonggangok appear to be the most suitable varieties for cultivation in terms of both quantity and feed value.

• Korean Journal of Organic Agriculture
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• v.19 no.2
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• pp.255-272
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• 2011

This work studied the growth and yield of green crops, changes of mineral composition in greenhouse soil and green crops, and infection with wintering green crops cultivation in greenhouse field. At 74 days after seeding of wintering green crops, dry matter was 710kg/10a in rye, 530kg/10a in barley, 230kg/10a in hairy vetch, and 240kg/10a in bean or weeds. Total nitrogen content in green crops was 4.5% in pea and hairy vetch, and 3~4% in barley and rye. $P_2O_5$, CaO, and MgO contents in all green crops were about 1.0%, and $K_2O$ content was the highest level by 4~5% among macro elements. Total nitrogen fixing content in shoot green crops uptaken from soil was 22.1kg/10a in rye, 20.6kg/10a in barley, 10.6kg/10a in hairy vetch, and 9.6kg/10a in pea and giant chickweed. $P_2O_5$ fixing content in shoot green crops uptaken from soil was 8.4kg/10a in rye, 6.3kg/10a in barley, and 2.3 kg/10a in hairy vetch and pea. $K_2O$ fixing content in shoot green crops uptaken from soil was 28kg/10a in rye, 24.7kg/10a in barley, and 11kg/10a in hairy vetch and pea. CaO fixing content in shoot green crops uptaken from soil was 2~3kg/ 10a in all green crops, and MgO fixing content was 1.7~2.6kg/10a in all green crops. Pepper growth in no-tillage was not a significant difference at all green manure crops. The number of fruit and fruit weight were higher in control, pea, hairy vetch and harvest barley than rye and barley. Soil mineral compositions in wintering green crops increased at pH, organic matter, CEC compared with control. Soil chemical compositions were stable level at green crops cultivation according as decreases of EC, available phosphoric acid, Ca, and Mg contents. After no-tillage by green manure crops, pH in soils was higher in green manure crops than control. EC content in soils was lower in green manure crops than control, and was remarkably low level in barley harvest. Organic matter content in soils increased in hairy vetch and barley green manure but decreased by 35% in barley harvest. Total nitrogen and avaliable $P_2O_4$ content in soils remarkably increased but was not a significant difference at all green manure crops. Cation (K, Ca, and Mg) content in soils decreased by 15~20% in K, 2~11% in Ca, and 3~6% in Mg at rye, barley and pea compared with control.

• Korean Journal of Weed Science
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• v.15 no.4
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• pp.254-261
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• 1995

The nationwide weed survey was conducted in lowland rice fields over whole country of Korea in 1992 in order to determine a change of weed community and to identify a major dominant weed species and/or problem weed. Based on morphological characteristics of weeds, population ratio of broad leaf weed was 42.6%, grasses weed-9.0%, sedges-33.4% and others were 15.0%. Annual weed was 33.4% while perennial weed was 66.6% in terms of life cycle of weeds. Meanwhile, there was different weed occurrence as affected by planting method of the rice plant. In hand transplanted paddy fields predominant weed species was Sagittaria trifolia L., Monochoria vaginalis Presl., and Aneilema japonica Kunth. In machine transplanted rice fields of infant and young rice seedling Eleocharis kuroguwai Ohwi. and S. trifolia L. were more predominant. There was high occurrence of M. vaginalis, Echinochloa crus-galli L., and Leesia japonica Makino in water seeding while E. crus-galli and Cyperus serotinus Rottb. were predominant weed species in dry seeded rice. Monoculture of the rice plant would cause to high occurrence of E. kuroguwai, S. trifolia, M. vaginalis, E. crus-galli, and Sagittaria pygmaea Miq and there was higher population of S. trifolia, S. pygmaea, M. vaginalis, E crus-galli, and E. kuroguwai in double cropping system based on rice culture. In particular, there was high different weed occurrence under different transplanting times. E. kuroguwai, S. trifolia, S. pygmaea, M. vaginalis, and C. serotinus were higher population at the transplanting of 25 May and S. trifolia, E crus-galli, C. serotinus, and M. vaginalis at 10 June and S. pygmaea, E. kuroguwai, M. vaginalis, S. trifolia, and E. crusgalli at 25 June in Korea, respectively. Autumn tillage in terms of tillage time would cause more predominant weed species such as S. trifolia, E. kuroguwai, M. vaginalis, and S. pygmaea while spring tillage was higher population of E. kuroguwai, S. trifolia, E. crusgalli, M. vaginalis, and S. pygmaea. In plain area of paddy field there was higher occurrence of E. kuroguwai, S. trifolia, M. vaginalis, E. crus-galli, and S. pygmaea and in mid-mountainous area S. trifolia, E. kuroguwai, M. vaginalis, E. crus-galli, and Ludwigia prostrate Roxb. while in mountainous area S. trifolia, M. vaginalis, Potamogeton distinctus Ben., E. kuroguwai, and E. crus-galli were. In 1992 the most ten predominant weed species at the rice field of Korea based on summed dominant ratio(SDR) were E. kuroguwai > S. trifolia > E. crus-galli > M. vaginalis > S. pygmaea > C. serotinus > L. prostrate > P. distinctus > A. japonica > Scirpus juncoides Roxb.