• Korean Journal of Microbiology
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• v.54 no.4
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• pp.362-368
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• 2018

Grasshoppers play vital role in the digestion of photosynthetically fixed carbons. With the aid of intestinal microflora, the grasshopper can degrade leaves constituents such as cellulose and hemicellulose. The purpose of this study was to examine cellulolytic yeast isolates from the gut of grasshoppers collected in Gyeonggi Province, South Korea. Among the yeast isolates, ON2, ON17 (two strains), and ON6 (one strain) showed positive cellulolytic activity in the CMC-plate assay. The sequence analyses of D1/D2 domains of the large subunit rDNA gene and the internal transcribed spacer (ITS) regions revealed that the strains ON2 and ON17 were most closely related to Papiliotrema aspenensis CBS $13867^T$ (100%, sequence similarity in D1/D2 domains; 99.4% sequence similarity in ITS) and strain ON6 related to Saitozyma flava (100% in D1/D2 domains; 99.0% in ITS). All these three yeast strains are capable of degrading cellulose; therefore, the members of endosymbiotic yeasts may produce their own enzymes for carbohydrate degradation and convert mobilized sugar monomers to volatile fatty acids. Thus, the endosymbiotic yeast strains ON2, ON17 (represents the genus Papilioterma) and ON6 (Saitozyma) belonging to the family Tremellomycetes, are unreported strains in Korea.

• Korean Journal of Agricultural and Forest Meteorology
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• v.22 no.4
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• pp.258-267
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• 2020

The agrivoltaic can produce electricity and grow crops on fields at the same time. It is necessary to analyze the cultivation environment and evaluate the crop productivity under agrivoltaic because the shading point changes according to structure of agrivoltaic and sun's position. Two types of "fixing" and "tracing" agrivoltaic were installed, and a rice cultivation experiment was conducted in the fields under each agrivoltaic and without shading (control). "Hyunpoombyeo" was transplanted on June 7, 2019, and grown with fertilization of 9.0-4.5-5.7 kg/10a (N-P-K). Fifteen weather stations were installed under each agrivoltaic to measure solar radiation and temperature, and yield and yield-related elements were investigated by points. The accumulated solar radiation during the rice growing season in fixing was no much difference between points, and that in tracing was much difference between points. However, the average solar radiations of two agrivoltaics were similar. The mean temperature, yield, and yield-related elements showed a significant difference for the shading rate, and decreased with increasing the shading rate except ripening grain rate and 1000 grain weight of fixing agrivoltaic. In the relationship between shading rate and yield, fixing and tracing were fitted to a logistic equation and a simple linear equation, respectively, and showed a high correlation (tracing: R2 = 0.62, fixing: R2 = 0.73). The shading rate variation by point for two types was large despite similar yield variation. Thus, it needs to be more closely examined the relationship of the shading rate for a specific period rather than the shading rate during the whole growing season.

• Korean Journal of Agricultural and Forest Meteorology
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• v.24 no.1
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• pp.48-61
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• 2022

South Korea is quite vegetation rich country which has 63% forests and 16% cropland area. Massive NOx emissions from megacities, therefore, are easily combined with BVOCs emitted from the forest and cropland area, then produce high ozone concentration. BVOCs emissions have been estimated using well-known emission models, such as BEIS (Biogenic Emission Inventory System) or MEGAN (Model of Emission of Gases and Aerosol from Nature) which were developed using non-Korean emission factors. In this study, we ran MEGAN v2.1 model to estimate BVO Cs emissions in Korea. The MO DIS Land Cover and LAI (Leaf Area Index) products over Korea were used to run the MEGAN model for June 2012. Isoprene and Monoterpenes emissions from the model were inter-compared against the enclosure chamber measurements from Taehwa research forest in Korea, during June 11 and 12, 2012. For estimating emission from the enclosed chamber measurement data. The initial results show that isoprene emissions from the MEGAN model were up to 6.4 times higher than those from the enclosure chamber measurement. Monoterpenes from enclosure chamber measurement were up to 5.6 times higher than MEGAN emission. The differences between two datasets, however, were much smaller during the time of high emissions. More inter-comparison results and the possibilities of improving the MEGAN modeling performance using local measurement data over Korea will be presented and discussed.

• Korean journal of applied entomology
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• v.61 no.4
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• pp.605-614
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• 2022

Two major problems currently threaten human survival on Earth: climate change and the rapid aging of the population in developed countries. Climate change is a result of the increase in greenhouse gas (GHG) concentrations in the atmosphere due to the increase in the use of fossil fuels owing to economic and transportation development. The rapid increase in the age of the population is a result of the rise in life expectancy due to the development of biomedical science and technology and the improvement of personal hygiene in developed countries. To avoid irreversible global climate change, it is necessary to quickly transition from the current fossil fuel-based economy to a zero-carbon renewable energy-based economy that does not emit GHGs. To achieve this goal, the dairy and livestock industry, which generates the most GHGs in the agricultural sector, must transition to using low-carbon emission production methods while simultaneously increasing consumers' preference for low-carbon diets. Although 77% of currently available arable land globally is used to produce livestock feed, only 37% and 18% of the proteins and calories that humans consume come from dairy and livestock farming and industry. Therefore, using edible insects as a protein source represents a good alternative, as it generates less GHG and reduces water consumption and breeding space while ensuring a higher feed conversion rate than that of livestock. Additionally, utilizing the functionality of medicinal insects, such as silkworms, which have been proven to have certain health enhancement effects, it is possible to develop functional foods that can prevent or delay the onset of currently incurable degenerative diseases that occur more frequently in the elderly. Insects are among the first animals to have appeared on Earth, and regardless of whether humans survive, they will continue to adapt, evolve, and thrive. Therefore, the use of various edible and medicinal insects, including silkworms, in industry will provide an important foundation for human survival and prosperity on Earth in the near future by resolving the current two major problems.

• Water for future
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• v.9 no.1
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• pp.38-42
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• 1976

Because of differences in thoughts and ideology, our country, Korea has been deprived of national unity for some thirty years of time and tide. To achieve peaceful unification, the cultivation of national strength is of paramount importance. This national strength is also essential if Korea is to take rightful place in the international societies and to have the confidence of these societies. However, national strength can never be achieved in a short time. The fundamental elements in economic development that are directly conducive to the cultivation of national strength can be said to lie in -a stable political system, -exertion of powerful leadership, -cultivation of a spirit of diligence, self-help and cooperation, -modernization of human brain power, and -establishment of a scientific and well planned economic policy and strong enforcement of this policy. Our country, Korea, has attained brilliant economic development in the past 15 years under the strong leadership of president Park Chung Hee. However, there are still many problems to be solved. A few of them are: -housing and home problems, -increasing demand for employment, -increasing demand for staple food and -the need to improve international balance of payment. Solution of the above mentioned problems requires step by step scientific development of each sector and region of our contry. As a spearhead project in regional development, the Saemaul Campaign or new village movement can be cited. The campaign is now spreading throughout the country like a grass fire. However, such campaigns need considerable encouragement and support and the means for the desired development must be provided if the regional and sectoral development program is to sucdceed. The construction of large multipurpose dams in major river basin plays significant role in all aspects of national, regional and sectoral development. It ensures that the water resource, for which there is no substitute, is retained and utilized for irrigation of agricultural areas, production of power for industry, provision of water for domestic and industrial uses and control of river water. Water is the very essence of life and we must conserve and utilize what we have for the betterment of our peoples and their heir. The regional and social impact of construction of a large dam is enormous. It is intended to, and does, dras tically improve the "without-project" socio-economic conditions. A good example of this is the Soyanggang multipurpose dam. This project will significantly contribute to our national strength by utilizing the stored water for the benefit of human life and relief of flood and drought damages. Annual average precipitation in Korea is 1160mm, a comparatively abundant amount. The catchment areas of the Han River, Keum River, and Youngsan River are $62,755\textrm{km}^2$, accounting for 64% of the national total. Approximately 62% of the national population inhabits in this area, and 67% of the national gross product comes from the area. The annual population growth rate of the country is currently estimated at 1.7%, and every year the population growth in urban area increases at a rising rate. The population of Seoul, Pusan, and Taegu, the three major cities in Korea, is equal to one third of our national total. According to the census conducted on October 1, 1975, the population in the urban areas has increased by 384,000, whereas that in rural areas has decreased by 59,000,000 in the past five years. The composition of population between urban and rural areas varied from 41%~59% in 1959 to 48%~52% in 1975. To mitigate this treand towards concentration of population in urban areas, employment opportunities must be provided in regional and rural areas. However, heavy and chemical industries, which mitigate production and employment problems at the same time, must have abundant water and energy. Also increase in staple food production cannot be attained without water. At this point in time, when water demand is rapidly growing, it is essential for the country to provide as much a reservoir capacity as possible to capture the monsoon rainfall, which concentarated in the rainy seaon from June to Septesmber, and conserve the water for year round use. The floods, which at one time we called "the devil" have now become a source of immense benefit to Korea. Let me explain the topographic condition in Korea. In northern and eastern areas we have high mountains and rugged country. Our rivers originate in these mountains and flow in a general southerly or westerly direction throught ancient plains. These plains were formed by progressive deposition of sediments from the mountains and provide our country with large areas of fertile land, emminently suited to settlement and irrigated agricultural development. It is, therefore, quite natural that these areas should become the polar point for our regional development program. Hower, we are fortunate in that we have an additional area or areas, which can be used for agricultural production and settlement of our peoples, particularly those peoples who may be displaced by the formation of our reservoirs. I am speaking of the tidelands along the western and southern coasts. The other day the Ministry of Agriculture and Fishery informed the public of a tideland reclamation of which 400,000 hectares will be used for growing rice as part of our national food self-sufficiency programme. Now, again, we arrive at the need for water, as without it we cannot realize this ambitious programme. And again we need those dams to provide it. As I mentioned before, dams not only provide us with essential water for agriculture, domestic and industrial use, but provide us with electrical energy, as it is generally extremely economical to use the water being release for the former purposes to drive turbines and generators. At the present time we have 13 hydro-electric power plants with an installed capacity of 711,000 kilowatts equal to 16% of our national total. There are about 110 potential dams ites in the country, which could yield about 2,300,000 kilowatts of hydro-electric power. There are about 54 sites suitable for pumped storage which could produce a further 38,600,000 kilowatts of power. All available if we carefully develop our water resources. To summarize, water resource development is essential to the regional development program and the welfare of our people, it must proceed hand-in-hand with other aspects of regional development such as land impovement, high way extension, development of our forests, erosion control, and develop ment of heavy and chemical industries. Through the successful implementation of such an integrated regional development program, we can look forward to a period of national strength, and due recognition of our country by the worlds societies.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.2
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• pp.30-37
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• 1964

Experiments were carried out to clarify the relationships between seed yields and some ecological characteristics, seed yields and some morphological characteristics, and the relationships among the varietal yields on the several sowing plots when grown under different climatic conditions. Twenty-four soybean varieties were used as the material, selected at random from 138 varieties which were cultivated the year before. These varieties were grown in the Experimental Farm, Chinju Agricultural College, Kyung Sang Namdo, Korea, and seed sowing was conducted at 5 times, from April to July, in 1962 and 1963. The results obtained are summarized as follows: 1. Correlations between seed yields and some ecological characteristics on the sowing date bases are shown in Table 1. Among some ecological characteristics, it was observed that there wert close relationships between seed yields and days to flowering, and between seed yields and the total growing length, except on the late sowing, i.e. July sowing plots, However, there was no clear correlation between seed yields and durations of flowering, and between seed yields and days from flowering to maturity. 2. Correlations between seed yields and some morphological characteristics on the sowing date bases are shown in Table 2. From this table, it was also observed that there were some close relationships between seed yields and branch number for plant, stem diameter, plant weight, pod number per plant, and grain number per plant, but there was no clear relationship between seed yields and stem length, and between seed yields and 100 grain weight, on every sowing plot. 3. Relations between varietal yields and the sowing dates are shown in Table 3. Our leading varieties such as Ulsan, Sangdoo, Changdan Backmok, Iksan, Haman, Barchongdeo, and Anion Daerip, which belong to the maturity groups of IV, V, and VI, have been significantly high in yield at each sowing date plot, but the extreme early varieties, that frequently are damaged by insects, moisture and diseases, and the extreme late varieties, that frequently are caught by frost suffering reduced yield, are showed a lower yield than the others. However, extreme early varieties, for instance, Black Hawk, an American variety, and Chung Buk Baek, a Korean early variety, showed high productivity on the late sowing, June and July sowing plots, and Do san No. 6, which is late Japanese variety, showed a high yield on the extreme early sowing, i.e. April sowing plots. 4. Relations between seed yields and the sowing dates on the varietal bases are shown in Table 4. It was observed that, the early varieties did not differ much in yields at the various sowing dates while the yields of late varieties decreased progressively with subsequent dates. However, the extreme late varieties, such as Tamanishiki, that frequently are caught by frost suffering reduced yield, may be difficult to harvest at this location. The results in these experiments showed that in most cases maximum yields were obtained when leading varieties, which are medium or late varieties, were shown in Mid-May, and progressively lower yields were produced from June and July sowings. On the other hand, the late sowings of the early varieties, such as Black Hawk and Chung Buk Baek, in these experiments showed favorable yields compared with the others. From these results, we can predict that our local medium or late varieties produce higher yields at this location than was produced by early varieties in most of the sowing dates, especially the May sowing, and early varieties such as Black Hawk and Chung Buk Baek should be used in the late sowing, June sowing time.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.2
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• pp.27-29
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• 1964

Experiments were carried out to clarify the relationships between seed yields and some ecological characteristics, seed yields and some morphological characteristics, and the relationships among the varietal yields on the several sowing plots when grown under different climatic conditions. Twenty-four soybean varieties were used as the material, selected at random from 138 varieties which were cultivated the year before. These varieties were grown in the Experimental Farm, Chinju Agricultural College, Kyung Sang Namdo, Korea, and seed sowing was conducted at 5 times, from April to July, in 1962 and 1963. The results obtained are summarized as follows: 1. Correlations between seed yields and some ecological characteristics on the sowing date bases are shown in Table 1. Among some ecological characteristics, it was observed that there wert close relationships between seed yields and days to flowering, and between seed yields and the total growing length, except on the late sowing, i.e. July sowing plots, However, there was no clear correlation between seed yields and durations of flowering, and between seed yields and days from flowering to maturity. 2. Correlations between seed yields and some morphological characteristics on the sowing date bases are shown in Table 2. From this table, it was also observed that there were some close relationships between seed yields and branch number for plant, stem diameter, plant weight, pod number per plant, and grain number per plant, but there was no clear relationship between seed yields and stem length, and between seed yields and 100 grain weight, on every sowing plot. 3. Relations between varietal yields and the sowing dates are shown in Table 3. Our leading varieties such as Ulsan, Sangdoo, Changdan Backmok, Iksan, Haman, Barchongdeo, and Anion Daerip, which belong to the maturity groups of IV, V, and VI, have been significantly high in yield at each sowing date plot, but the extreme early varieties, that frequently are damaged by insects, moisture and diseases, and the extreme late varieties, that frequently are caught by frost suffering reduced yield, are showed a lower yield than the others. However, extreme early varieties, for instance, Black Hawk, an American variety, and Chung Buk Baek, a Korean early variety, showed high productivity on the late sowing, June and July sowing plots, and Do san No. 6, which is late Japanese variety, showed a high yield on the extreme early sowing, i.e. April sowing plots. 4. Relations between seed yields and the sowing dates on the varietal bases are shown in Table 4. It was observed that, the early varieties did not differ much in yields at the various sowing dates while the yields of late varieties decreased progressively with subsequent dates. However, the extreme late varieties, such as Tamanishiki, that frequently are caught by frost suffering reduced yield, may be difficult to harvest at this location. The results in these experiments showed that in most cases maximum yields were obtained when leading varieties, which are medium or late varieties, were shown in Mid-May, and progressively lower yields were produced from June and July sowings. On the other hand, the late sowings of the early varieties, such as Black Hawk and Chung Buk Baek, in these experiments showed favorable yields compared with the others. From these results, we can predict that our local medium or late varieties produce higher yields at this location than was produced by early varieties in most of the sowing dates, especially the May sowing, and early varieties such as Black Hawk and Chung Buk Baek should be used in the late sowing, June sowing time.

• Current Research on Agriculture and Life Sciences
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• v.9
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• pp.1-9
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• 1991

Bulbs of two introduced garlic cultivars, Sanghae-joseng and Spain strain, were purchased in a market and anatomical characteristics of them were investigated according to the weight of individual bulbs. The materials used were planted and grown in the field. Bulbs harvested were classified according to weight and their anatomical characteristics were recorded. 1. In both cultivars the larger the bulb, the more flat the bulb shape. 2. The bigger the bulbs were, the larger the number of cloves per bulb was, Spain strain had more cloves per bulb than Sanghae-joseng in the same size bulbs. 3. In Sanghae-joseng, more cloves were formed in outer layer than in inner layer in the bulbs produced in 1990. But more cloves were formed in inner layer in the bulbs of 35 g or smaller produced in 1991. In Spain strain, more cloves were formed in inner layer in the bulbs of 40 g or more produced in 1990. But more cloves were formed in outer layer in the bulbs produced in 1991 regardless of bulb size. In both cultivars, the number of primary cloves and total number of cloves was very small in both cultivars, but it was a little bigger in Sanghae-joseng than in spain strain. 5. In the bulbs produced in both 1990 and 1991 of Spain strain and in bulbs produced in 1990 of Sanghae-joseng weight of cloves in outer layer was significantly heavier than that in outer layer, the trend was not conspicuous in 1991 produce of Sanghae-joseng. 6. In both cultivars clove size range was narrow in small bulbs and wide in large bulbs. In distribution of cloves in size, medium ones were most frequent, and the frequency of large cloves increased with increased size of bulbs. Sanghae-joseng produced larger cloves than Spain strain in the same size cloves.

• Korean Journal of Organic Agriculture
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• v.19 no.2
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• pp.185-198
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• 2011

This study was carried out to select a proper forage crop, and to estimate the proper level of application of cattle manure and carrying capacity of organic livestock per unit area. Corns and forage sorghum hybrids were cultivated with different types of livestock manures and different amount of them to produce organic forage. For both corns and forage sorghum hybrids, no fertilizer plots had significantly (p<0.05) lower annual dry matter (DM), crude protein (CP) and total digestible nutrients (TDN) yields than those of other plots, whereas the N-P-K (nitrogen-phosphorous-kalium) plots ranked the highest yields, followed by 150% cattle manure plots and 100% cattle manure plots. DM, CP and TDN yields of in cattle manure plots were significantly (p<0.05) higher than those of no fertilizer and P-K (phosphorous-kalium) plots. The yields of in cattle slurry plots tended to be a little higher than those of in composted cattle manure plots. Assuming that corn and forage sorghum hybrids produced from this trial were fed at 70% level to 450kg of Hanwoo heifer for 400g of average daily gain, the carrying capacity (head/year/ha) of livestock ranked the highest in 150% cattle slurry plots (mean 6.0 heads), followed by 100% cattle slurry plots (mean 5.3 heads), 150% composted cattle manure plots (mean 4.7 heads), 100% composted cattle manure plots (mean 4.4 heads), and no fertilizer plots (mean 2.8 heads) in corns (or the cultivation of corns). Meanwhile, in the case of forage sorghum hybrids, 150% cattle slurry plots (mean 6.4 heads) ranked the highest carrying capacity, followed by 150% composted cattle manure plots (mean 4.8 heads), 100% cattle slurry plots (mean 4.4 heads), 100% composted cattle manure plots (mean 4.1 heads), and no fertilizer plots (mean 2.8 heads). The results indicated that the application of livestock manure to cultivated soil could enhance not only DM and TDN yields, but also the carrying capacity of organic livestock as compared with the effect of chemical fertilizers. In conclusion, the production of organic forage with reutilized livestock manure will facilitate the reduction of environmental pollution and the production of environmentally friendly agricultural products by resource circulating system.

• Korean Journal of Weed Science
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• v.18 no.3
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• pp.205-213
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• 1998

This experiment was carried out to produce herbicide resistant potatoes hawing only chimeric phosphinothricin acetyltransferase (PAT) genes without using antibiotic selectable marker. The pDY502 vector having only PAT gene was reconstructed for transformation of potato. The reconstructed vector was introduced to Agrobacterium tumefaciens MP90 disarmed, and they were used for potato transformation. Hormonal requirement for plant regeneration from leaves and stem explants of potato was investigated. From this experiment, MS medium treated with IBA 0.1 mg/L + BA 0.5 mg/L was the best for potato regeneration, and the ratio of shoot regeneration was 54% for leaf and 46% for stem in that condition. For transformation, explants of potato leaves and stems were cocultured with A. tumefaciens MP90 containing reconstructed vector harvoring only PAT gene. When the potato explants were placed on various concentrations of bialaphos and all the potato explants were dead on medium with over 5.0mg/L bialaphos. By this selection methods, the explants cocultured with Agrobacterium produced the putative transgenic shoots on medium with 5mg/L bialaphos treatment after 3-4 weeks. Second selection was performed by transferring the shoot tips of putative transgenic to medium containing 20mg/L of bialaphos. The shoot tips grew well on the second selection medium, indicating the production of successful transgenic plants. But normal shoots were dead in same cytotoxic medium. Incorporation of the PAT gene into transgenic potatos were confirmed by PCR analysis of DNA and Southern hybridization. These results show that the PAT gene can serve as a selectable marker and herbicide resistant genes for transformation of potato.