• Korean Journal of Soil Science and Fertilizer
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• v.21 no.1
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• pp.49-54
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• 1988

The present experiment was conducted to investigate causes affecting the reduction of red pepper production in the continuous cultivation upland soil from 1985 to 1986 in Imsil Chonbuk Province. The results obstained are summarized as follows: 1. Area ratio of continuous cultivation 2 years was 12.7%, 3 years 6.8% and over 4 years 48.9%. 2. Soil hardness and volume of solid and liguid of red pepper continuous cultivation soil were higher than those of one year cultivation, while pH and content of organic matter of continuous cultivation soil were low. The exceeding optimum level of phosphorus and potassium appeared factors affecting and reduction of red pepper of continuous cultivation soil. 3. Microflora density in continuous cultivation soil was high but bacteria/fungi (B/F) and actinomycetes/fungi (A/F) ratio were low. 4. The density of soil nematodes in continuous cultivation soil were higher than that in one year cultivation soil, however, the steeper and better drainage soil lowered the density of nematodes. 5. Continuous cultivation over 4 years showed 14.3% of plants diseased by phytophthora while 0.7% in one year cultivation soil.

• Korean Journal of Soil Science and Fertilizer
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• v.48 no.5
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• pp.456-463
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• 2015

The objective of this study was to determine the effects of granular type of silicate fertilizer on watermelon growth, yield, and characteristics of soil in the greenhouse. Four different levels of silicate fertilizer, 0(control), 600, 1,200, $1,800kg\;ha^{-1}$ were applied for experiment. The silicate fertilizer was applied as a basal fertilization before transplanting watermelon. Compost and basal fertilizers were applied based on the standard fertilizer recommendation rate with soil testing. All of the recommended $P_2O_5$ and 50% of N and $K_2O$ were applied as a basal fertilization. The N and $K_2O$ as additional fertilization was split-applied twice by fertigation method. Watermelon (Citrullus lanatus Thunb.) cultivar was 'Sam-Bok-KKuol and main stem was from rootstock (bottle gourd: Lagenaria leucantha Standl.) 'Bul-Ro-Jang-Sang'. The watermelon was transplanted on April, 15. Soil chemical properties, such as soil pH, EC, available phosphate and exchangeable K, Mg, and available $SiO_2$ levels increased compared to the control, while EC was similar and the concentrations of soil organic matter decreased. Physical properties of soils, such as soil bulk density and porosity were not different among treatments. The growth characteristics of watermelon, such as stem diameter, fresh and dry weight of watermelon at harvest were thicker and heavier for silicate treatment than the control, while number of node was shorter than the control. Merchantable watermelon increased by 3-5% compared to the control and sugar content was 0.4 to $0.7^{\circ}Brix$ higher than the control. These results suggest that silicate fertilizer application in the greenhouse can improve some chemical properties of soils and watermelon stem diameter and dry weight, which are contributed to watermelon quality and marketable watermelon production.

• Animal Bioscience
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• v.34 no.12
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• pp.2023-2033
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• 2021

Objective: The present study was conducted to assess the effect of urease inhibitor (hydroquinone [HQ]) and nitrification inhibitor (dicyandiamide [DCD]) on nitrogen (N) use efficiency of pig slurry for perennial ryegrass regrowth yield and its environmental impacts. Methods: A micro-plot experiment was conducted using pig slurry-urea ¹⁵N treated with HQ and/or DCD and applied at a rate of 200 kg N/ha. The flows of N derived from the pig slurry urea to herbage regrowth and soils as well as soil N mineralization were estimated by tracing pig slurry-urea ¹⁵N, and the N losses via ammonia (NH₃), nitrous oxide (N₂O) emission, and nitrate (NO₃^-) leaching were quantified for a 56 d regrowth of perennial ryegrass (Lolium perenne) sward. Results: Herbage dry matter at the final regrowth at 56 d was significantly higher in the HQ and/or DCD applied plots, with a 24.5% to 42.2% increase in ¹⁵N recovery by herbage compared with the control. Significant increases in soil ¹⁵N recovery were also observed in the plots applied with the inhibitors, accompanied by the increased N content converted to soil inorganic N (NH₄⁺+NO₃^-) (17.3% to 28.8% higher than that of the control). The estimated loss, which was not accounted for in the herbage-soil system, was lower in the plots applied with the inhibitors (25.6% on average) than that of control (38.0%). Positive effects of urease and/or nitrification inhibitors on reducing N losses to the environment were observed at the final regrowth (56 d), at which cumulative NH₃ emission was reduced by 26.8% (on average 3 inhibitor treatments), N₂O emission by 50.2% and NO₃^- leaching by 10.6% compared to those of the control. Conclusion: The proper application of urease and nitrification inhibitors would be an efficient strategy to improve the N use efficiency of pig slurry while mitigating hazardous environmental impacts.

• Korea Science and Art Forum
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• v.37 no.5
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• pp.239-248
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• 2019

This study started from the need to improve one of shortcomings of synthetic PVAc adhesives - potential physical harm and environmental hazards to the workers or their users. As a matter of fact, PVAc adhesives are currently mainly used because of their convenience and economy for the production of woodcrafts. The purpose of this study was to develop natural adhesives through research on natural adhesives in step with the current increase of societal attention to environmental friendliness and rapid surge in their demand in the face of such problems. So, the study attempted research on the bases to develop natural adhesives for woodcraft, using cellulose extracts from wood - natural adhesive material. The findings of the study were as follows. Firstly, natural adhesives showed the improved effect in the field of adhesive strength, a basic physical property by 0.2 - 4 times compared with the existing materials and the study confirmed they had the similar or stable pH value. Besides, they had good reversibility, demonstrating their basic physical property as a natural adhesive for woodcraft. While, their durability to ultraviolet ray degradation also showed an excellent result value being better by 1.5 - 8.5 times than the existing materials. The study expects natural adhesives with improved and better performances compared with the existing materials could be developed, if further research on adhesive strength, antibiosis, conservative property were to continue by developing refinery technology for cellulose extracts from wood and rendering the functionality to them.

• Animal Bioscience
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• v.34 no.6
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• pp.1049-1060
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• 2021

Objective: This study assessed the effect of different levels of xylanase, β-glucanase and phytase on intestinal enzyme activities and tibia bone development in broiler chickens fed wheat-based diets. Methods: Twelve experimental diets were formulated using a 3×2×2 factorial design (three doses of phytase and two doses of both xylanase and β-glucanase) and offered to 648 day-old Ross 308 male chicks having 6 replicates groups with 9 birds per replicate and lasted for 35 days. Results: An interaction between the enzymes products improved (p<0.01) the activity of chymotrypsin. Protein content at d 10 was highest (p<0.001) with addition of phytase while general proteolytic activity (GPA) (p<0.02) and lipase activity (p<0.001) were decreased. At d 24, there were improvements in protein content (p<0.01) and lipase (p<0.04) with supplementation of superdose phytase. Addition of superdose phytase decreased in chymotrypsin (p<0.02), trypsin (p<0.01) and GPA (p<0.001). The optimum dose of xylanase decreased the chymotrypsin activity (p = 0.05), while the GPA (p<0.001) was increased with the optimum level of β-glucanase. Superdose phytase supplementation at d 10 improved maltase (p = 0.05), sucrase (p<0.001) and alkaline phosphatase (p<0.001) activities in the jejunum while aminopeptidase activity was highest (p<0.005) with the low level of phytase. Protein content of jejunum mucosa was bigger (p<0.001) in birds fed superdose phytase while maltase activity (p<0.001) at d 24 was reduced by this treatment. Sucrase (p<0.04) and aminopeptidase activities (p<0.001) improved when diets supplemented with low levels of phytase. Tibia bone breaking strength was highest (p<0.04) with addition of low level of superdose phytase or optimum level of β-glucanase. Bone dry matter content decreased (p<0.04) when diets supplemented with phytase. Conclusion: From the results obtained in this study, supplementation of superdose phytase was the most effective, however, the cost-benefit analysis of the use of such a dose needs to be evaluated.

• Korean Journal of Organic Agriculture
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• v.28 no.4
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• pp.615-626
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• 2020

The objective of present experiment was to examine the impact of different organic nitrogen (N) fertilizer application rates and different harvesting periods on the forage yield and feed value of kenaf (Hibiscus cannabinus L.). This study was carried out from May to September 2019, the amount of 80 kg of kenaf seed/ha were applied with different rates of nitrogen fertilizer. The plants were sampled at 10 days intervals (100, 110, 120, and 130 days after seeding) from different harvesting dates. In the organic fertilizer treatments, the highest dry matter (DM) yield was observed in the application rate at 250 kg of N/ha. Crude protein (CP) content in leaves was similar between the organic fertilizer rates at 200 and 250 kg of N/ha and were higher compared with other fertilizer treatments. The highest CP content in the stem was 4.3% in the organic fertilizer application rates st 250 kg of N/ha. Neutral detergent fiber (NDF) in leaves showed no significant difference between the chemical fertilizer rates at 200 and 250 kg of N/ha, and the organic fertilizer rates at 150 and 250 kg of N/ha. In addition, DM yield of kenaf was highest in the harvest of 100 days after seeding, and tended to decreased significantly with increase of harvesting periods (p<0.05). As the growth progressed, the plant height and stem ratio increased but the leaves ratio decreased significantly (p<0.05) and the highest was found at 110 days after seeding. The highest CP, Acid detergent fiber (ADF), NDF and total digestible nutrient (TDN) contents in leaves were 13.9, 25.4, 40.5 and 71.1%, respectively that were affected by different harvesting periods. Also, the ADF and NDF in stem increased significantly with increase of kenaf maturity (p<0.05). In conclusion, the optimal organic fertilizer application rates and the proper harvesting periods for the forage yield and quality of kenaf were at 200 to 250 kg of N/ha, and 100 to 110 days after seeding, respectively.

• The Korean Journal of Archival Studies
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• no.27
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• pp.169-208
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• 2011

In this thesis, I pursued how the concept of documentary photography in Korea was formed, and how Koreans perceive the current mix of some concepts and how they are tracked that. Korean photography society, directly or indirectly, accepted the concept and format of documentary photography of the United States in which information and discussion of the history and concept by examining the process of being transferred to Korea are examined. Giroksajin(記錄寫眞) is a translation word of documentary photography which was a part of documentary movements in the United States of the 1930s, and are all based on that concept. When we order Korean documentary photography and the subject matter must be distinct, attitude toward the things should be based on the exact perceptions of this age awareness, to be able to give enough information, and finally moved forward to move the human emotion must be. When this condition is equipped with the photographers and archivists perspective is revealed clearly the social and historical records that are meaningful. Documentary photography is the subject of the photographers and archivists that want to record the important things, but what you can get in the records and the question of how to use it is also important. Korean documentary photography, not only records the things, just to have a meaningful supplement to get done the exact context of information production and led to the conclusion that the strengthening of documentation strategies.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.9
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• pp.1381-1388
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• 2019

Objective: The aims of this study were to reveal the magnitude of the differences in protein structures at a cellular level as well as protein utilization and availability among soybean meal (SBM), canola meal (CM), and rapeseed meal (RSM) as feedstocks in China. Methods: Experiments were designed to compare the three different types of feedstocks in terms of: i) protein chemical profiles; ii) protein fractions partitioned according to Cornell Net Carbohydrate and Protein System; iii) protein molecular structures and protein second structures; iv) special protein compounds-amino acid (AA); v) total digestible protein and energy values; vi) in situ rumen protein degradability and intestinal digestibility. The protein second structures were measured using FT/IR molecular spectroscopy technique. A summary chemical approach in National Research Council (NRC) model was applied to analyze truly digestible protein. Results: The results showed significant differences in both protein nutritional profiles and protein structure parameters in terms of ${\alpha}-helix$, ${\beta}-sheet$ spectral intensity and their ratio, and amide I, amide II spectral intensity and their ratio among SBM, CM, and RSM. SBM had higher crude protein (CP) and AA content than CM and RSM. For dry matter (DM), SBM, and CM had a higher DM content compared with RSM (p<0.05), whereas no statistical significance was found between SBM and CM (p = 0.28). Effective degradability of CP and DM did not demonstrate significant differences among the three groups (p>0.05). Intestinal digestibility of rumen undegradable protein measured by three-step in vitro method showed that there was significant difference (p = 0.05) among SBM, CM, and RSM, which SBM was the highest and RSM was the lowest with CM in between. NRC modeling results showed that digestible CP content in SBM was significantly higher than that of CM and RSM (p<0.05). Conclusion: This study suggested that SBM and CM contained similar protein value and availability for dairy cattle, while RSM had the lowest protein quality and utilization.

• Journal of The Korean Society of Grassland and Forage Science
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• v.39 no.2
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• pp.68-74
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• 2019

'Choyoung', a winter forage triticale cultivar (X Triticosecale Wittmack), was developed at the Department of Rice and Winter Cereal Crop, NICS, RDA in 2015. The cultivar 'Choyoung' has the leaves of medium width, long length and green color and a medium grain of brown color. The heading date of the cultivar 'Choyoung' was April 30 which was 2 days earlier than that of check cultivar 'Shinyoung'. Its tolerance or resistance to cold, wet injury, powdery mildew, and leaf rust was similar to those of the check cultivar. But the resistance to the lodging of cultivar 'Choyoung' was stronger than that of the check. The average forage fresh and dry matter yield of cultivar 'Choyoung' at milk-ripe stages were 40.5 and $15.7MT\;ha^{-1}$, respectively, which were similar to those (40.3 and $16.1MT\;ha^{-1}$) of the check cultivar. The silage quality of 'Choyoung' was higher than that of the check cultivar 'Shinyoung' in crude protein content (5.9%), while was similar to the check cultivar 'Shinyoung' in acid detergent fiber (33.9%), neutral detergent fiber (57.3%), and total digestible nutrients (62.2%). It showed a grain yield of $5.59MT\;ha^{-1}$, which was 38% higher than that of the check cultivar 'Shinyoung' ($4.05MT\;ha^{-1}$). This cultivar is recommended for fall sowing forage crops in areas in which average daily minimum mean temperatures in January are higher than $-10^{\circ}C$.

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.12
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• pp.1881-1889
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• 2018

Objective: In dryland areas of China, alfalfa hay (AH) is a possible substitute for concentrate feed for beef cattle. To evaluate the potential benefits of this substitution, we studied the effect of the ratio of AH intake to total dry matter (DM) intake on average daily body-weight gain (ADG), dietary energy utilization status, and economic benefit in Gansu province. Methods: In each of two feeding trials in 2016 (trial 1 [T1], July 3 to 17; trial 2 [T2], August 15 to September 23), crossbred male Simmental calves were allocated to low AH (LA), medium AH (MA), and high AH (HA) feeding groups (n = 4 per group). The target ADG was set as 1 kg for both trials. In a one-way-layout design based on conventional feeding practices in the province, calves received diets containing the different AH amounts, with a constant ratio of corn stover:total DM and decreasing rations of concentrate feed proportional to the increase in AH. Calves in T1 received AH at 15% (T1-LA), 23% (T1-MA), or 31% (T1-HA) of their dietary DM allowances; those in T2 received 9% (T2-LA), 24% (T2-MA), or 34% (T2-HA) AH. Results: Among the T1 groups, both ADG and economic benefit were highest in T1-LA; whereas in T2, they were higher in the T2-LA and T2-MA groups than in T2-HA. Energy digestibility did not significantly differ among the groups in either trial. The dietary AH inclusion ratios of 14% in the warm season and 8% to 21% in the cool season appeared to yield optimal ADG, metabolizable energy intake, and economic benefit. Conclusion: Low-level inclusion of AH, ranging from 8% to 21%, is a practical approach for beef cattle feeding. This modified feeding regimen likely will promote increased growth performance during the fattening stage of beef steers in dryland areas of Gansu province, China.