• Journal of The Korean Society of Grassland and Forage Science
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• v.35 no.3
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• pp.225-231
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• 2015

Improving current pasture productivity by precision management requires practical tools to collect site specific pasture biomass data. Recent developments in unmanned aerial vehicle (UAV) technology provide cost effective and real time applications for site specific data collection. For the mapping of herbage biomass (BM) on a hill pasture, we tested a UAV system with digital cameras (visible and near-infrared (NIR) camera). The field measurements were conducted on the grazing hill pasture at Hanwoo Improvement Office, Seosan City, Chungcheongnam-do Province, Korea on May 17 and June 27, 2014. Plant samples were obtained from 28 sites. A UAV system was used to obtain aerial photos from a height of approximately 50 m (approximately 30 cm spatial resolution). Normalized digital number (DN) values of Red and NIR channels were extracted from the aerial photos and a normalized differential vegetation index using DN ($NDVI_{dn}$) was calculated. The results show that the correlation coefficient between BM and $NDVI_{dn}$ was 0.88. For the precision management of hilly grazing pastures, UAV monitoring systems can be a quick and cost effective tool to obtain site-specific herbage BM data.

• Journal of The Korean Society of Grassland and Forage Science
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• v.31 no.2
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• pp.167-176
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• 2011

본 연구는 우분액비의 시용이 경사도를 달리한 사료용 옥수수 재배지에서 옥수수의 생산성 및 유거수 중의 N의 유실에 미치는 영향을 조사하기 위하여, 건국대학교 축산대학 사료작물 시험포 내 설치된 Erosion apparatuses (가로 0.33 m, 세로 3 m, 깊이 0.4 m)를 이용하여 수행하였다. 시험구의 경사도는 0%, 8.75%, 17.50%로 하였으며, 우분액비는 6개월 이상 부숙된 것으로 질소 기준 200 kg/ha 시용하였다. 옥수수의 건물생산성과 사료가치는 경사도에 의해 영향을 받았으며, 17.50% 경사지의 건물생산성은 0% 경사지의 건물생산성에 비해 유의적인 감소를 보였다 (P<0.05). 유거수 중의 평균 $NO_3^--N$과 $NH_4^+-N$의 농도는 경사가 높아질수록 유의적으로 증가하였다(P<0.05). 이상의 결과에서 보는 바와 같이 우분액비를 시용하여 사료용 옥수수를 재배할 경우, 경사도가 증가할수록 그리고 집중호우가 발생할 경우에 유거수 중의 양분 유실량은 증가가 예상되기 때문에 경사도가 심한 지역에서 옥수수를 재배할 때에는 양분유실에 따른 수질오염을 고려하여 사료작물 재배 방법이 모색되어야 한다.

• Journal of The Korean Society of Grassland and Forage Science
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• v.12 no.2
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• pp.98-103
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• 1992

With a purpose of finding out the effects of cattle slurry application on thc nutrient contents of herbages and energy productivity in grassland, a field experiment was conducted with two times and five levels of cattle slurry application. The experimental field was designed in a split-plot with threc replications, and lasted from September, 1986 to October, 1990 at the Livestock Experiment Station in Suweon, The results obtained are summarized as follows: 1. The net energy(NEL, StE and TDN) contents of grasses in the plots with cattle slurry application just after cutting were slightly higher when compared to manuring 15 days after cutting. but DCP content has reverse trend. 2. Average net energy(NEL. StE and TDN) and DCP production of the plot with cattle slurry application 15 days after cutting were insignificantly increased by 26 % than those of manuring just after cutting. The energy and DCP yields in the plot with cattle slurry and with slurry + mineral fertilizer were decreased by 21 -27 % and 8- 11 %, respectively than those of the plot with single dressing of mineral fertilizer. 3. Mineral contents of grasses were not significant difference among the treatments of cattle slurry. but considering nutrient balance of animals, application of cattle slurry of 30-$60m^3$/ha with mineral fertilizer was profitable as compared to the other treatments.

• Journal of The Korean Society of Grassland and Forage Science
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• v.14 no.1
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• pp.13-17
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• 1994

To find out the effects of phosphatic fertilizer application level on the dry matter yield and nutrient contents of grasses, this experiment was arranged as a randomized complete block design with six treatments(0, 50, 100, 150, 200 and 250kg $P_2O_5$/ ha) and conducted at hill land in Gwangju, Gyeonggi Province from September, 1989 to October, 1992. The results obtained are summarized as follows : 1. As the phosphatic fertilization level increase, the early growth and cover degree of grasses wintered were more favorable and plant length was higher. 2. With 150kg $P_2O_5$/ ha application for three years, the average dry matter yield of grasses, 10,112kgl ha was sirnilared to that of 200kg $P_2O_5$/ ha and the yield was composed of 77.2% grasses(7,808kg/ ha), 19.2% legumes(l,937kg 1 ha) and 3.6% weeds(367kg / ha). 3. The crude protein and energy productivity of grasses increase as phosphatic fertilization level was increased, but those were not different between 150 and 250kg $P_2O_5$ 1 ha. Therefore, phosphatic fertilization level must be applied with 150kg / ha for a reasonable management in hilly grassland.

• Journal of The Korean Society of Grassland and Forage Science
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• v.10 no.3
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• pp.179-182
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• 1990

This experiment was carried out to determine the proper application time of nitrogen (N) and potassium ($K_2O$) as a additional fertilizer in corn cultivation at Taekwalyong alpine area.Two varieties of silage corn (cv. Suwon 19 and Kangwon local var.) were grown under different top dressing time (4-leaf, 7 leaf and 10-leaf stage) in 1989.Kangwon local variety produced more leaf area and higher dry matter yield than Suwon 19. However,there was no describle differences among application time of N and $K_2O$ fertilizer in both Suwon 19 and Kangwon local variety.

• Journal of The Korean Society of Grassland and Forage Science
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• v.10 no.3
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• pp.137-140
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• 1990

This study was carried out to investigate the effects of slope exposure and altitude on the dry matter yield and on the grass quality in mountain pasture for 2-year period from 1986 to 1987. 1. Dry matter yield and crude protein content of grasses by slope exposure in mountain pasture were higher on the northern slope than that on the southern slope and, on both sides of slope, were increased as the altitude was high. 2. Neutral detergent fiber(NDF) and acid detergent fiber(ADF) contents, and in vitro dry matter digestibility were not different between different slope exposures and between different altitudes.

• Journal of The Korean Society of Grassland and Forage Science
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• v.37 no.3
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• pp.237-241
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• 2017

Drought is one of the detrimental factors that impair plant growth and productivity. In this study, we applied annealing control primer (ACP)-based reverse transcriptase PCR (polymerase chain reaction) technique to identify differentially expressed genes (DEGs) in maize leaves in response to drought stress. Two-week-old maize seedlings were exposed to drought (DT) by suspending water supply. DEGs were screened after 3 days of DT-treated samples using the ACP-based technique. Several DEGs encoding 16.9 protein, antimicrobial protein, hypothetical protein NCLIV_068840, thioredoxin M-type were identified in maize leaves under drought stress. These genes have putative functions in plant defense response, growth and development. These identified genes would be useful for predictive markers of plant defense, and growth responses under drought stress in plants.

• Journal of Practical Agriculture & Fisheries Research
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• v.3 no.1
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• pp.102-115
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• 2001

Through out the last few decades, processing methods for ingredients of feed grains, such as grinding, flaking, extrusion, soaking, cracking etc., have been adopted in order to improve the nutrient digestibility in ruminants. Among feed grains, processing methods for whole corns have been the most frequently studied since corns are utilized as the thumb ingredients in formulating feeds. In these days, flaking of whole corns is the most incessantly used in formulation feeds, resulting in enhancing the performance of ruminants. Recently formulating non-forage feed for beef cattle, especially Holsteins, without processing whole corns is carrying out through various feed companies with expectations of whole corns acting like forages. However, it can not be ruled out that whole corns might possibly result in decreasing the productivity due to the depression of nutrient utilizations. Therefore, one must reevaluate the non-forage feeds as well as makes an effort to develop the rational and effective methodology in processing whole corns with the consideration of rumen eco-system.

• Journal of The Korean Society of Grassland and Forage Science
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• v.44 no.3
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• pp.210-214
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• 2024

Drought stress is one of the major factors that reduce plant growth and productivity. This study was conducted to investigate the effect of exogenous acetic acid pretreatment on drought stress tolerance response in plants. Fourteen-day-old alfalfa plants were pretreated with 15 mM acetic acid, and then subsequently subjected to drought stress for 6 days. The fresh weight and relative water content in the leaves of acetic acid pretreated alfalfa plants were increased compared to the control group. The chlorophyll and carotenoid contents were slightly decreased in the acetic acid treatment. The H₂O₂ and proline contents were also significantly decreased in the acetic acid treatment. These results suggest that the scavenging mechanism of reactive oxygen species in alfalfa activated by acetic acid pretreatment is involved in conferring tolerance to drought stress.

• Journal of The Korean Society of Grassland and Forage Science
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• v.9 no.2
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• pp.62-67
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• 1989

A breeding program in progress at Suweon Livestock Experiment Station, RDA, involves the hybridization of italian ryegrass (Lm) and several leading forage grasses in an effort to combine the nutritive, productivity and palatability qualities of Lm with the adaptive and cold resistance qual; .les of several leading grasses. In order to study the fate of the hybridization between remotely related species, immatured hybrid embryos were cultured on media. The emasculated plants of Lm were Sikem and Tetrone. Reweille, 2n=14, of perennial ryegrass (Lp.), Forager, 2n=42, of tall fescue(Fa), First, 2n=14,of meadow fescue(Fp), Potomac, 2n=28, of orchardgrass(Dg), and Richmond, 2n=42, of timothy(Ph.p) were used as pollinators. Embryos were isolated on 4, 8, 12, 16, and 20 days after pollination and cultured them on modified Murashige and Skoog media. Calluses and plantlets have been obtained after 8 days old embryos crossing between $Lm{\times}Fa$, after 12 days embryos crossing between $Lm{\times}Lp$, Dg, and Ph.p, and after 16 days embryos crossing between $Lm{\times}Fp$. Both callus and shoot formation occurred on 6 % or less of the plated embryos of $Lm{\times}Fp$, Dg, and Ph.p. Embryoderived callus forming shoots have been obtained from 4 days old embryo crossing between $Lm{\times}Dg$ which has not successfully been done anywhere as far as we know. It means that hybrid plants of species without crossability can be obtained through the use of immatured embryo culture. Some of plated embryos developed directly shoots from embryos and the others shoot-forming callus. Cross between related species showed a high frequency of directly shoot formation from plated embryos and cross between remotely related species a high frequency of callus formation.