• Journal of The Korean Society of Grassland and Forage Science
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• v.11 no.2
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• pp.97-101
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• 1991

This experiment was carried out to determine the effect of pure mineral nitrogen fertilization on dry matter yield and the amounts of advisable mineral nitrogen on grassland according to its age at the "Federal Institue for Agriculture in the Alps" in Austria. The results obtained were as follows: 1. With only PK-fertilizing average dry matter yields per year were progressively declined during the period of the studies. Compared with the relatively younger grassland(1st-5th year) the DM-yields were decreased by 35% in older grassland (11th-final year). 2. Due to the less reduction of DM-yields by mineral nitrogen application according to the age of grassland. With N-fertilizing the reduction of DM-yields in relatively older grassland was less than that of younger grassland by 11-21%. 3. At 4-and 5-cut systems the nitrogen amounts for the highest marginal yield(the "most efficient" Ndressing rate) per ha and year were distinctly declined in the relatively older grassland. 4. Required efficiencies of mineral nitrogen were not influenced by the age of grassland.he age of grassland.

• Journal of Ginseng Research
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• v.35 no.2
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• pp.155-161
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• 2011

Leaf characteristics of mature 2, 3 and 4-year-old North American ginseng (Panax quinquefolius L.) leaves on fruiting and non-fruiting(NF) plants were studied. Leaflets of the 2-year-old plants had the lowest fresh and dry weight, area, volume and internal gas volume. Inflorescence removal in 3-year-old plants did not affect leaf characteristics or ginsenoside concentration but in 4-year-old plants it increased leaf fresh (38.6%) and dry (43.9%) weight, leaf area (29.1%), specific leaf mass (11.4%), leaf volume (43.1%), and leaf thickness (12.1%), and decreased leaf water content (6.2%). Cultivated ginseng, although an understorey plant, had the specific leaf mass, 35.6 g $m^{-2}$ (range, 36 to 39 g $m^{-2}$) and a chlorophyll a/b ratio of 2.40 to 2.61, both suggesting the ability to perform like a sunny habitat plant. Also, specific leaf mass of 35.6 g $m^{-2}$ is similar to that reported for perennial plants, 36.8 g $m^{-2}$, rather than that for annuals, 30.9 g $m^{-2}$.

• Korean Journal of Soil Science and Fertilizer
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• v.47 no.1
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• pp.8-15
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• 2014

In order to evaluating physiochemical properties of soil under minimum tillage and direct seeding cultivation on dry rice paddy, we conducted to analyze the soil physiochemical characteristics in treatment with 2-year minimum tillage and dry direct seeding (2MT), 3-year minimum tillage and dry direct seeding (3MT), and tillage transplanting cultivation (TT). As results of analyzing soil organic matter (OM) contents with 2 cm soil depth of interval from surface to 30 cm, OM contents with surface soil from 0 to 2MT and 3MT were higher than TT, recorded 34.6, 28.1 and $19.8gkg^{-1}$, respectively. But until 20cm in soil depth, it was not so large on the deviation of OM contents among the 3 treatments comparing with 2cm surface. Beneath 20 cm in soil depths, 2- and 3-year, OM contents in TT were distributed to be lower than 2MT and 3MT. The contents of total nitrogen in 2MT and 3MT were higher than the content in TT across the soil profile. Consequently, though minimum tillage and direct seeding farming is obviously the practice to saving of machinery work and labor, other practices such as continuously input OM should be needed to achieve carbon sequestration goal through minimum tillage and direct seeding on dry paddy.

• Journal of The Korean Society of Grassland and Forage Science
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• v.14 no.4
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• pp.264-270
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• 1994

This experiment was undertaken to determine the effect of pasture ages on the total production and seasonal yield trends, botanical composition and forage quality of pasture mixtures. This experiment was conducted at the Livestock Experiment Station, RDA, Suweon. The results obtained were as follows : 1. Total dry matterDM) yield of pasture mixtures was the highest in the first year, and thereafter no significant reduction in the 2nd through the 4th year, but decreased by 30% in the 5th year. 2. The 34.4% of total DM yield was produced at the first cut, and decreased from then on. Total DM yield of pasture mixtures varied by year and climatic facton. In 1992, Total DM and TDN yields of pasture mixtures were 13.4 and 8.5 IvlT/ha, respectively. 3. The content of crude protein(CP), in virro DM digestibility(IVDMD) and TDN of pasture mixtures were 12-14, 70-80, and 62-65%, respectively. The highest forage quality was obtained at the 4th cutting. 4. The botanical compositions of legumes and weeds were increased as the year of establishment advanced, and highly increased at the 3rd cut after summer growth. 5. Based on the results of this study it appears that economic forage production could be expended to the 4th year with proper management, and the special renovation techniques may be needed for maintenance of pasture yield from the 5th year.

• Korean Journal of Organic Agriculture
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• v.12 no.4
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• pp.411-425
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• 2004

The aim of this experiment was to investigate the effects of applying times and dilution rates of cattle slurry with water on dry matter yields and feed values of orchard grass. Cattle slurry was applied at the rates of average nitrogen fertilizer equivalent to 150kg/ha/year in 3 cutting frequency. Significantly higher dry matter yields than that of no fertilization (7.36 ton DM/ha) were recorded in the application of diluted cattle slurry (10.74~13.54 ton DM/ha) (p<0.05). Especially, this tendency was shown with higher annual dry matter yields at the partitioned dressing times, such as at the applications for 1st and 3rd growth, 2nd and 3rd growth, and 1st, 2nd and 3rd growth respectively. The yields of annual dry matter at fertilizing phosphorus, potassium and nitrogen were higher than no fertilization as 12.42 tons per ha. However, with application of diluted cattle slurry, dry matter yields per year (11.96 ton DM/ha) were significantly higher than those of fertilizing phosphorus and potassium (7.52 ton DM/ha) (p<0.05). The efficiencies of dry matter production with mineral and cattle slurry nitrogen application (kg DM/kg N) were 32.7 and 13.4~26.9kg DM/kg N respectively. Especially, these tendencies were higher in diluted application plots than in no-diluted application plots of cattle slurry. The contents of crude protein (CP, %), neutral detergent Eber (NDF, %), acid detergent fiber (ADF, %), annual yields of CP (kg/ha) and total digestible nutrient (TDNY, kg/ha) of orchardgrass were significantly higher at the application of diluted cattle Slurry than those at non-fertilizer application (p<0.05).

• Journal of Plant Biology
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• v.14 no.4
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• pp.19-26
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• 1971

The sample stand of Pinus rigida plantation was chosen from those at the Choongnam Forest Experiment Station, Choongnam. The diameter at breast height (D) and the height of tree (H) of each tree in the sample plot of 200$m^2$ were measured yearly a from 1967 through 1969. The stand was 12.7-13.4cm in mean diameter and had a stand density of 2,150 trees per ha. The trunk, branches and leaves of each sample tree were separately weighed according to the stratified clip technique. The allometric relation between D2H and dry weight of trunk (Ws), branches (Wb) and leaves (Wl) were approximated by $$W_s=0.05917 (D^2H)^{0.837}$$ $$W_0=0.00655 (D^2H)^{0.989 }$$ $$W_l=0.04466(D^2H)^{0.690}$$ From the above, the standing crops in the sample stand was estimated to be as much as 76.7, 81.7 and 88.2 tons of dry matter, above ground, per ha in 1967, 1968 and 1969, respectively. Annual net production, as the sum of the biomass newly produced during one year, was estimated at 4.97-5.47 tons per ha per year. The respiratory and the photosynthetic rate deduced from theoretical calculations were 0.045 and 0.74kg of dry matter per kg per year. Tentative estimate of annual respiratory loss was made and annual gross production was roughly estimated at 4.4-4.7 and 10.7-12.9 tons of dry matter per ha per year. The ratio of respiratory loss to gross production was approximately 36-41:1.

• Journal of Ecology and Environment
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• v.41 no.9
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• pp.246-255
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• 2017

Background: The aim of this study was to examine the resource allocation among the organs and the leaf morphology of Polygonatum humile. The data were collected from June 2014 to May 2015 in a natural P. humile stand of a temperate forest gap. Results: The dry weight of new rhizome ($R_0$) sharply decreased to the time of new shoot sprouting in next year and was constant for 2 ~ 3 years. However, dry weight of root on $R_0$ increased to the end of growth season and, thereafter, decreased slowly along the time elapsed. The correlation coefficients between the rhizome and the leaf sizes were 0.5 for the last year's rhizome ($R_1$) and 0.6 for $R_0$ and were significant at 0.1% level for $R_0$. The increase of one leaf a plant led to increase of the total leaf area, total leaf weight, and stem length. Moreover, the organ sizes' differences between two plants of the one leaf difference were almost significant at 1% level. In 11-leaf plant, the leaf length/width ratio and specific lea area increased to the second, relative leaf area to the fourth and relative leaf dry weight to the fifth, and thereafter, decreased to the last leaf. The differences in the values of these four parameters between two leaves on a stem were almost significant at 5% level. Conclusion: P. humile examined showed the close relationships between the last year's rhizome or this year's one and the shoot system (leaf and stem) sizes. The leaf number a shoot greatly influenced specific leaf area. P. humile's leaf might showed diverse morphology with leaf rank on a stem in a forest gap environment.

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.12
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• pp.1768-1773
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• 2016

This experiment was conducted to determine the effect of variety and planting year on the nutritive values of corn fed to growing pigs. Four corn varieties examined in this experiment were planted in the same village located in Longhua County, Heibei Province, China, in 2012, 2013, and 2014, respectively. During each year, corn was hand-harvested in early October and sun dried to about 14% moisture content. Three batches of twenty-four barrows ($33.27{\pm}4.30$, $31.88{\pm}2.93$, $34.21{\pm}3.81kg$ body wight [BW] in 2012, 2013, and 2014, respectively) were used and allotted to a complete block design with 4 diets and 6 replicate pigs per diet. Pigs were individually placed in metabolic crates. The four experimental diets were formulated by mixing each variety of corn and vitamins and minerals, respectively. A five-day collection period followed a seven-day diet acclimation period. The results indicated that variety of corn significantly influenced the available energy content (digestible energy [DE] on dry matter basis, p<0.05; metabolizable energy (ME) on dry matter basis, p<0.05, respectively), and the apparent total tract digestibility (ATTD) of organic matter (p<0.01), dry matter (p<0.05), gross energy (p<0.05), neutral detergent fiber (p<0.01), acid detergent fiber and ether extract (p<0.05). The planting year also significantly influenced the available energy contents (DE on dry matter basis, p<0.05; ME on dry matter basis, p<0.01, respectively) and the ATTD of neutral detergent fiber (p<0.01), acid detergent fiber (p<0.01), crude protein (p<0.01), and ether extract (p<0.01). No interaction was observed between the variety and planting year in DE and ME contents in corn. In conclusion, the variety and planting year significantly influenced the available energy and nutrient digestibility of corn fed to growing pigs.

• Journal of The Korean Society of Grassland and Forage Science
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• v.17 no.4
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• pp.407-414
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• 1997

In this study, the optimum cutting 6equency and level of mineral nitrogen fertilization were investigated for the production of Reed canarygrass in uncultivated rice paddy. The results are summarized as follows; 1. Higher relative dry matter yields were recorded in 2nd cut of plots with 3 and 5 cutting frequencies, and 3rd cut of plot with 4 cutting kquency, respectively. 2. With no nitrogen fertilization, mean dry matter yields per year were 6.2~7.6 tonsha and the highest yield appeared in plot with 4 cutting 6equency. 3. The increased fertilization of mineral nitrogen resulted in the increased dry matter yield. Significantly higher dry matter yields than that of no nitrogen fertilization were recorded in fertilization of 90 kg nitrogen per year in 3 cutting fequency, 240 kg in 4 cutting frequency and 150 kg in 5 cutting 6equency respectively. 4. Efficiency of dry matter production with nitrogen fertilization(kg DMkg N) was higher in 30kg Nhalcut in 3 and 5 cutting eequency, 60kg Nhalcut in 4 cutting 6equency respectively. In each cutting kequency, the higher efficiency of dry matter production appeared in 1st cut in 3 cutting kequency, and 2nd cut in 4 and 5 cutting 6equency respectively. 5. Economic N level(kg/ha) was 179.5~242.3kg/ha in 3 cutting 6equency, and 189.6-241.6kg/ha and 167.0 ~253.2kg/ha in 4 and 5 cutting 6equency respectively, and marginal dry matter yields were 11.4~ 12.3 tons/ ha, 11.2 ~ 11.8 tons/ha and 8.3 ~9.1 tons/ha in 3, 4 and 5 cutting 6equency respectively. 6. The limiting N fertilization level to the highest dry matter were estimated to be 569.9kg/ha, 492.4kg/ha and 654.lkg/ha in 3, 4 and 5 cutting kequency respectively.

• Corrosion Science and Technology
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• v.2 no.4
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• pp.183-188
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• 2003

Corrosion of carbon and weathering steels were evaluated under 3 environmental exposures in Thailand (urban, rural and marine) for a year. The seasonal study was designed to determine different corrosion mechanisms by 6 months of dry season and 6 months of rainy season in a year. The sheltered exposure racks were used to determine the washing effect of min. At each site, climatic and pollutants analyses were carried out. The present study showed that the difference in corrosion rates of carbon and weathering steels was not so distinguished in both rural (AIT) and urban (TISTR) environments. The corrosion rate of weathering steel was somewhat lower than that of carbon steel and the decreasing tendency of corrosion rate with time was slightly higher for weathering steel than for carbon steel. In marine (Rayong) environment, the corrosion rate was higher and the effect of wet and dry seasons was observed. The corrosion rate in 6 dry months was higher for direct exposure than for sheltered exposure. However, in 6 rainy months. the corrosion rate of sheltered exposure was higher than that of direct exposure. In direct exposure for I year, that is, the first 6 dry months and the next 6 rainy months, the corrosion rate decreased with time. but in sheltered exposure, the corrosion rate did not decrease with time. instead, increased in the next 6 rainy months. This indicated that the protect ive layer formed in the first 6 dry months could be destroyed by high deposition of chloride to r sheltered exposure in the next 6 rainy months; whereas the rust layer for direct exposure could be kept sound due to washing effect in rainy season, even though the deposition rate of chloride was almost the same for direct and sheltered exposures. In marine environment, the weathering steel showed higher corrosion resistance than carbon steel but its corrosion rate was higher than those in other environments.