• Journal of The Korean Society of Grassland and Forage Science
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• v.12 no.3
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• pp.134-140
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• 1992

사일리지의 사양가치에 가장 크게 영향을 미치는 요인은 사초의 종류에 기인되는 화학조성분이며 사일리지를 적기에 제조하므로 단위면적당 최고의 양분수량을 거둘 수 있다. 유기산의 생성량이 많고 낙산이나 암모니아태질소의 함량이 많으면 사일리지의 품질이 떨어지고 섭취량이 감소되므로 사일리지 품질 증진을 위한 연구방향은 발효를 감소시키고 단백질의 분해를 막는 것이다. 사일리지의 발효에 영향을 미치는 중요한 요인으로는 사초의 화학조성분인 수분, 수용성탄수화물 등과 제조기술에 크게 좌우되는 공기(산소)혼입량이다. 재료의 수분함량은 사일리지 발효품질에 큰 영향을 미치며 수분이 많은 재료는 적당히 예건되면 젖산발효는 덜 제한되는 반면 불필요한 발효가 줄어들고 낙산발효를 억제할 수 있어 품질이 향상되고 기호성이 증진된다. 또한 사초를 알맞은 길이로 절단하므로 답압이 잘되어 공기 배출이 양호해 혐기상태의 유지가 가능하게 되고 사일리지의 취급또한 편리해 진다. 사일리지 첨가제는 재료를 적절히 예건하지 못할 때 필요하고 또한 특별한 조건하에서는 권장되고 있다. 이와같이 사일리지 발효에 도움을 준다는 가능성에도 불구하고 첨가제의 잇점은 양질 사일리지 제조를 위한 제반 처리를 대신할 수 없다. 양건 건초제조에 소요되는 기간은 기후에 크게 영향을 받게 된다. 건초제조 과정 중 포장에서 생기는 건물손실은 외기에 오랫동안 노출되면 잎이나 연한 줄기 부분이 부서지고 카로틴이 파괴된다. 또한 말리는 과정에 비를 맞힐 경우 양분이 용해되어 소화되기 쉬운 영양소와 건물 손실이 증가되며 섬유소함량이 증가되어 소화율과 섭취량이 감소된다. 그러므로 일기 예보에 따라 좋은 날씨가 $3\sim4$일 계속되는 시기를 택하여 적기 수확하고, 줄기의 압쇄(condition), 건조시 풀의 두께를 얇게, 뒤집기, 적절한 수분함량일 때 거둬들이는 조치가 필요하다.

• Journal of The Korean Society of Grassland and Forage Science
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• v.35 no.1
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• pp.17-25
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• 2015

The following experiments were used to evaluate the effect of seeding method and pre-emergence herbicides on weed control and the production of the $sorghum{\times}sudangrass$ [sorghum bicolor (L.) Moench] hybrid under field and in vitro conditions. Under the in vitro condition, we evaluated how different kinds of herbicides affect the rate of seed germination and the growth of early seedlings in the $sorghum{\times}sudangrass$ hybrid treated with herbicides. Simazine, alachlor, and methabenzthiazuron were used, and their concentration levels were 0%, 40%, 70%, and 100%. The germination ratio of the seeds was reduced by the application of simazine, methabenzthiazuron, and alachlor compared with the control (distilled water). The alachlor application severely decreased the sorghum germination ratio. However, seed germination was not greatly influenced by the concentration level of the herbicides. Root and shoot length were increased in the following order: control > simazine > methabenzthiazuron > alachlor. Overall, alachlor significantly reduced root length more than shoot length. The differential tolerance of the $sorghum{\times}sudangrass$ hybrid to pre-emergence herbicides by seeding method was then tested under the field condition. The plants were severely injured by the alachlor application, leading to a great reduction in the number of stems. However, for the simazine and methabenzthiazuron applications the number of stems lost was slightly lower than it was for the alachlor and simazine + alachlor applications. In the seeding method, drilling was more effective in reducing herbicide injury than broadcasting. All of the herbicides effectively controlled weeds. The simazine and methabenzthiazuron applications showed a significantly higher dry matter (DM) yield. However, the alachlor and simazine + alachlor applications severely reduced the DM yield. This result suggests that the alachlor application has a significant effect on plant production. Similarly, the total digestible nutrient (TDN) yield was greatly reduced by the alachlor and simazine + alachlor applications. From the results presented above, we concluded that the yield of DM was the highest for broadcasting with no herbicide. and drilling was the most-effective way to reduce herbicide injury. The simazine application was the most-effective herbicide, showing the highest forage yield and TDN yield.

• Applied Biological Chemistry
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• v.25 no.4
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• pp.232-238
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• 1982

From ^{15}N$ labelled nitrogen experiments on 13 fields use efficiency by difference method was higher than that by labelling method in 80% of fields tested indicating augmentation of soil nitrogen uptake by fertilizer nitrogen. Both methods showed very similar trend among fields. Sulfur coated urea(SCU) and point application increased fertilization efficiency(yield increment per fertilizer nitrogen applied, Fe) to 23 from 15 of split application through the increase of fertilizer use efficiency from 29(Eu) to 50 but tended to decrease efficiency of absorbed fertilizer nitrogen(yield increment per nitrogen derived from fertilizer, Ef) from 50. to 46 High yielding capacity of Tongil line appears to be attributed to the higher Ef, translocation efficiency and soil nitrogen preference index(soil nitrogen increment in plant per the increment of fertilizer nitrogen in plant, PI). This studies confirmed that yield under fertilizer application system depends on Fe which is the multiplication of Eu and Ef and that the improvement of fertilizer management(form, application method and time) increases principally Eu, the limit of which is controlled by Ef that is attributed mainly to varietal characteristics.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.52 no.2
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• pp.208-212
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• 2007

This experiment was carried out to investigate critical date for wet direct seeding of rice after barley harvest in Honam plain areas. Three early maturing cultivars of Samchonbyeo, Sangjubyeo and Obongbyeo and two medium maturing cultivars of Geumobyeo 1 and Juanbyo were tested under four different seeding dates. Seedling stand was higher with earlier seeding date with the range from 68 to 81% then later seeding date. Field lodging occured severely in Samchonbyeo, Sangjubyeo and Geumobyeo 1, while it was not apparent in Obongbyeo and Juanbyo. In consideration of threshold heading date, critical seeding date was June 20 in Samchonbyeo, Sangjubyeo and Obongbyeo of early maturing cultivars, and June 15 in Geumobyeo 1 and Juanbyo of medium maturing cultivars. Milled rice yield significantly decreased in seeding date of June 15 or late. These results implied that critical date of seeding for wet direct seeding after barley cropping in Honam plain area was June 10.

• Korean Journal of Soil Science and Fertilizer
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• v.29 no.1
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• pp.3-7
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• 1996

Effects of the nitrogen application time and amounts on the nitroger. uptake and recovery of fertilizer nitrogen applied at panicle formation stage was investigated in connection with the growth and yield of rice drill-seeded in puddle-soil. silt loam of Jeonbuk series. Urea was applied as nitrogen source. Nitrogen uptake and recovery of fertilizer nitrogen by rice plant was highest in the treatment applied nitrogen at 20 days before heading. Culm length, internode length (4th and 5th) and lodging index were increased by earlier application time and higher level of nitrogen. but filled grain ratio and 1,000 grain weight showed the opposite trend Panicle number per square meter and grain number per panicle was significantly decreased in nitrogen application at 10 days before heading. Rice yield was the highest in 33kgN/ha(conventional amount at 20days before heading, and yield in 26kgN/ha(80% of conventional amount) at 20 days before heading and in 33kg/ha at 15days before heading were nearly the same as conventional treatment.

• Journal of Ginseng Research
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• v.32 no.4
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• pp.279-282
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• 2008

This study was conducted to compare the aerial parts growth, yield of fresh ginseng roots, quality of red ginseng roots, and photosynthesis (Fv/Fm, PSII) in leaves between non-irrigation plot and furrow irrigation plot during the ginseng growing seasons. The aerial part growth in furrow irrigation plot was higher than non-irrigation plot in all including the emergency rate, leafing rate and relatively growth rate. Root yield per 10a in irrigation plot was increased about 50% as compared with that of non-irrigation, also heaven and earth grade of red ginseng roots yield in irrigation plot was higher (40.3%) compared with that (30.6%) of non-irrigation plot in 6-years-old ginseng plant. Furrow irrigation markedly improved the ginseng quality and yield in comparison to non irrigation condition. Therefore it needs to control the soil moisture during the growing season for high yield and good qualities of ginseng roots.

• Korean Journal of Environmental Agriculture
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• v.30 no.2
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• pp.138-143
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• 2011

BACKGROUND: This study was conducted to investigate growth and yield of organically grown rice under a typhoon during a fall. The treatments included NPK chemical fertilizer, compost, oilcake, oilcake 2X, hairyvetch, and vetch+rye. METHODS AND RESULTS: Nutrient applications were made at rates equivalent to approximately 0.9 kg of actual N per acre. Oilcake and hairyvetch treatments had the lowest C:N ratio, but compost had the highest C:N ratio of 34:1. Rice treated by organic nutrient sources had great growth and development at the beginning of the growing season but had depressed growth and yield at the harvest. Oilcake 2X-treated rice in early growing season, especially, showed better growth and development than rice treated by other nutrient sources but was severely lodged at the harvest season due to the typhoon. Compost treatment with high C:N ratio slowly released inorganic N and produced poor rice growth and yield; however, it recued rice lodging. N uptake was the greatest for the oilcake 2X and vetch+rye treatments but the lowest for the compost, which was the similar pattern to the N use efficiency; the greatest and lowest N use efficiency was observed for the oilcake 2X (55%) and compost (5%), respectively. CONCLUSION(s): Rice lodging should be prevented by reducing the excessive nitrogen supplement, resulting from the lower C:N ratio of the organic materials as well as prevented by the radical midsummer drainage. Vetch+rye treatment with 25:1 of C:N had optimum vegetative growth and reduced rice lodging, which increased N use efficiency and yield.

• Korean Journal of Medicinal Crop Science
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• v.7 no.3
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• pp.200-204
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• 1999

Ligusticum chuanxiong has been an important oriental crude drug and cultivated for a long time in Korea. Ligusticum chuanxiong has been vegetatively propagating crop without seed due to its sterility and would be an allodiploid derived from the hybridization of two allied species. Generally, vegetative propagation is more costly per unit propagule than sexual(seedling) propagation. This study was conducted to find out the techniques of mass propagation by stem cutting for reduced seedling cost. When cutted on August 30 with 1st to 2nd internode, its highest rooting percentage was 81 percent. Rhizome yield of plants cutted in 50 percent on September 1 decreased to 9 percent less than control (rhizome propagation). Rooting percentage of rooted cutting plants after field planting on October 25 was the highest being 87 percent. Rhizome yield with planting appeared 127 and 120kg/10a on September 25 and October 25, respectively.

• The Korean Journal of Pesticide Science
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• v.14 no.3
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• pp.241-246
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• 2010

Field experiments were carried out to establish economic threshold for com borer (Ostrinia furnacalis (Guen$\'{e}$e)) on waxy com plants by examining the number of adult insects caught in pheromone traps and the injury levels of waxy com which were artificially controlled. Adult com borers were lured into the pheromone traps during the whole growth period in five areas in Gangwon province including Chuncheon. The number of com borers trapped was the greatest in Chuncheon followed by Cheolwon and Hongcheon, and the same trend was observed for injury level of waxy com. Based on marketable yield data of waxy com plants related to the artificially-controlled injury levels at tassel stage, spray threshold was determined as the injury level of 11~15%, where the injury of com plants exceeded the economically admitting level.

• Journal of Bio-Environment Control
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• v.23 no.4
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• pp.314-320
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• 2014

Three leaf vegetables, namely green lettuce, red lettuce (Lactuca sativa) and red-veined chicory (Cichorium intybus) were grown in minigreenhouses covered with two new functional films and conventional polyethylene film (PE). Seedlings of leaf vegetables were transplanted in a plastic troughs filled with soil-perlite mixture. Two functional films were made from polyolefin (PO) material. Measurement of optical characteristics showed that polyolefin films have better transmittance for the photosynthetic active radiation (PAR, 400-700nm) and higher absorptance for the ultraviolet radiation (UV, 300-400nm) in comparison with the conventional PE film. After three months of utilization higher loss in PAR transmittance was observed for conventional PE film. Leaf vegetables growth was enhanced and yield was increased in greenhouses covered by new functional films.