• Korean Journal of Environmental Agriculture
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• v.19 no.5
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• pp.382-393
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• 2000

The principal indicators contributing to water qualities was screened by factor analyses, based on the monitored chemical parameters of water quality for various water resources from 1995 to 1999 in the small agricultural catchments of the Han River Basin. Water samples of streams, groundwaters, and reservoirs were taken four times a year from upper (Daegwanryong), middle (Dunnae and Chunchon) and lower (Guri) reaches of Han River Basin. In these areas, the respective type of farming practiced was alpine agriculture and livestocks raising, typical upland and paddy cultivation, and intensive cropping in the plastic film house. Water quality was monitored for twenty-one water quality parameters, including pH, EC, SS, T-N, T-P, COD, cations, anions, and heavy metals. pH, EC and COD of the stream waters were suitable for the Korea irrigation water quality guidelines. However, T-N and T-P concentrations of water samples in four catchments far exceeded the irrigation water guideline. Concentrations of canons and heavy metals in Wangsuk stream in Guri area were higher than those in streams in other areas. Factor analysis revealed that significant correlation was observed for 81 pairs out of 231 water quality indicators of stream water among the $21\;{\times}\;21$ cross correlation matrix of stream water quality indicators. The first factor accounted for 27.01% of the total variation in stream water quality indicators, and high positive factor loadings were shown on EC, K, Na, $NH_4\;^+-N$, $PO_4\;^{3-}$, $SO_4\;^{2-}$, and COD. Fifty-three water quality indicator pairs were significant out of 190 ground water quality parameters. The first factor accounted for 28.54% of the total variation in ground water quality indicators, and high loadings were revealed on EC, Ca, Mg, K, Na, $NH_4\;^+-N$, and $SO_4$. Twenty-nine pairs of reservoir water quality indicators were significant out of 66 pairs. The first factor accounted for 37.06% of the total variation in reservoir water quality indicators, and high loadings were shown on EC, Mg, K, Na, SS, T-P, Cl, and COD. These results demonstrate that EC was the first factor contributing to water quality.

• Journal of Environmental Impact Assessment
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• v.25 no.1
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• pp.77-87
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• 2016

Predicting possible distributed area of Schisandra chinensis which has long term cultivation period among non-timber forest products is needed to be studied to deal with climate change. Hence, distribution of Schisandra chinensis in the 2050s and 2070s was predicted under two scenario, RCP 4.5 and RCP 8.5, with ensemble of 5 climate models used in IPCC AR5. According to estimation using RCP 4.5, distribution of Schisandra chinensis in 2050s appeared to decrease 43% of current area and appeared to decrease 57% in 2070s respectively. Moreover, According to estimation using RCP 8.5, distribution of Schisandra chinensis in 2050s appeared to decrease 55% of current area and appeared to decrease 85% in 2070s. As a final outcome, Schisandra chinensis was estimated to extinct in the future except Gangwon-do and Gyeongsangbuk-do when analyzing change between current distributed area and future distributed area. As a result, those areas were classified as vulnerable areas to climate change. Therefore, Gangwon-do and Gyeongsangbuk-do were thought to be ideal for growing Schisandra chinensis. The result from this study can be used to provide basic information for selecting proper area of Schisandra chinensis considering climate change effect.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.65 no.1
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• pp.56-62
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• 2020

The meteorological ecology of a soybean variety (Glycine max Merrill) and its characteristics are important factors in selecting soybean variety suitable for the environment. This experiment was conducted to estimate the meteorological- ecological characteristics of soybean for 27 crop cultivation regions in North Korea. The meteorological ecology of each region was determined by the last harvest date and the maximum growth day determined using the daily minimum temperature of the region. The soybean meteorological group for 27 regions in North Korea was classified by eight groups. The last harvest date of group I, the south-west and south-east areas, was from October 21 to 29, which was the latest harvest date among the eight groups. It became shorter toward the central inland and mountainous areas of group IV, and it ranged from September 18 to October 2. The maximum number of growth days was 153~160 days in group I, and 100~111 days in group IV-3, the northernmost area of the east coast. Assuming total growth days as 110 days, the ranges of last flowering dates (and the day length) of group I, II, III, and IV were August 12~19 (day length of 13.5~13.8 h), August 2~6 (14-14.2 h), July 27~August 2 (14.2~14.4 h), and July 10~22 (14.5~14.8 h), respectively. The accumulative temperature of 110 growth days was above 2,400℃ in group II-1, the south to north area of the west inland, and above 2,300℃ in all regions except Cheongjin, Seonbong, and Jung-gang. The accumulative temperature calculated based on the maximum growth day was above 3,000℃ in group I and II-1 and above 2,500℃ in group II-2, the central area of the east coast, III-1, the central inland area, and IV-1, the central inland mountain area.

• Journal of Soil and Groundwater Environment
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• v.15 no.1
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• pp.50-56
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• 2010

Oil contamination soil has been one of the most environmental social issues for decades in the inside and outside of country. The law of soil environmental preservation was carried out in the 1990s and the government controlled not only soil environment management and the remediation of contaminated soil but also promoted the development of remedial technology and cleanup business of contaminated soil by national policy. In addition to agriculture areas, the main oil contaminated sites are a gas station, oil reservoir, petro-chemical complex, site of railway carriage base and military camp. The contamination-frequency of agriculture area and effect sites are low but it has significantly important area on account of producing food for human beings. Therefore, we should be concerned about oil contamination damage of agriculture area. The oil contamination damage of agriculture area influenced drop of birth and breeding since the oil directly adheres to seeds and farm products even diffusion of contaminated soil to cultivation area. The studies of the crops and the food vegetation has not enough detailed data caused by the incident of oil contamination. This study investigated the effect of oil in germination and growth of selected plant seeds. In this study, we try to verify whether the oil contamination by accidents on farmland influenced the damage of farm produce and the mutual relation both oil contaminated soil or the vegetation of crops. The impact of oil on plant development was followed by phytotoxicity assessments. The plants exhibited visual symptoms of stress, growth reduction and perturbations in developmental parameters. The increase of the degree of pollution induced more marked effects in plants, likely because of the physical effects of oil. The relationships between the phytotoxicity contents of plants and growth reduction suggest a chemical toxicity of fuel oil. In addition, while cleaned up the contaminated soil under the standard of contaminated soil we examined it was suitable for region standard and it may have practical possibility for fill material of construction of afforestation and molding soil of landfill.

• Korean Journal of Plant Resources
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• v.27 no.4
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• pp.344-353
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• 2014

This study was carried out to analyze the effect of arsenic types on growth and arsenic accumulation ability of Pteris multifida. Among arsenic pollution sources, Sodium arsenate, Calcium arsenate, Sodium arsenite and Potassium arsenite were treated in horticultural compost contaminated with $500mg{\cdot}kg^{-1}$. P. multifida was cultivated for 12 weeks. The results of study, Calcium arsenate treatment showed slightly decreased growth of P. multifida. But, growth of P. multifida cultivated in the remaining arsenic treatment was similar to untreated control plot. With only short-term cultivation of 4 weeks, aerial part of P. multifida in Sodium arsenate treatment showed high arsenic accumulation of $2,289.5mg{\cdot}kg^{-1}DW$. The arsenic accumulation ($2,956.0mg{\cdot}kg^{-1}DW$) was the highest at 12 week. On the other hand, underground part showed the highest arsenic accumulation in Potassium arsenite treatment ($2,470.2mg{\cdot}kg^{-1}DW$) and Calcium arsenate treatment accumulated $1,060.7mg{\cdot}kg^{-1}DW$ of arsenic. Regardless of arsenic types, aerial part of P. multifida was absorbed more than $1000mg{\cdot}kg^{-1}DW$ of arsenic. And removal of arsenic in soil was also higher. Therefore, Pteris multida is considered to be suitable phytoremediation meterial of various arsenic contaminated areas.

• Journal of Distribution Science
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• v.16 no.8
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• pp.63-68
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• 2018

Purpose - Lettuce (Lactuca sativ L.) is one of the economically important vegetable crops, which worldwide market value is over 100 billion U.S. dollar. In Korea, about 89.7 kilo ton of lettuce was produced in 3400ha in 2016, recoded as No. 1 vegetable crop in domestic green house production. However, recently, domestic lettuce production and cultivation areas are all getting decreased. Thus, novel approaches are needed to be implemented to revive the production. Research design, data and methodology - In this review paper, we first prioritized the end-user traits which are imperative to positively stimulate the domestic lettuce market and discussed relevant genomics strategies. Especially, we assessed a possibility whether school meal program would be a potential niche market. Results - The genomics technologies, which become widely applied in the crop biotechnology since 2008 when next generation sequencing method was developed, may be a good solution in the crop improvement, efficiently gathering valuable information of agriculturally useful traits. Significantly, in lettuce, the high quality whole genome sequence, based on Lactuca sativa cv. Salinas, is publically available and this genomics platform, thus, would be implemented in lettuce breeding program to innovate relevant end-user traits both for the farmers and customers, including the disease resistance to the Fusarium wilt, productivity under hot weather conditions, various nutritional qualities and so forth. These improvements will boost domestic lettuce industries in the near future. Conclusions - Due to the nutritional distinctions comparing to the western style lettuces, domestic leaf lettuces could be one of the important vegetables in the school meal programs. To make it happen, we would better devise diverse recipes to make a salad with it, instead of only using as a wrap vegetable. Meanwhile, novel lettuce varieties need to be developed, which are favorable to the students and also easy to be handled with while processing. Overall, to achieve international competence in the lettuce industries, we need to create elite lettuce varieties that satisfies domestic farmers as well as customers, suitable to various niche markets, such as school meal program. Thus, efficient breeding programs using genomics approaches should be established in advance and careful monitoring on the preference of the related customers for a niche market be continued persistently.

• Magazine of the Korean Society of Agricultural Engineers
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• v.21 no.2
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• pp.28-36
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• 1979

One of most important problems in the Monsoon Asia today is the production of rice paddy to meet the needs of the ever increasing population. Diversemeans are being employed to meet this demand, both by increasing productivity of existing farm land and by bringing further areas into cultivation. The primary step in either field is to ensure that there is sufficient moisture in the soil to suit the paddy, and at the same this means that excess moisture has to be drained off the land, while in others irrigat ion has to be employed to bring sufficient water to an area. In view of the fact that the project comprises a huge amount of earthwork, it can be carried out by extensive use of construction machinery in order to shorten the period. As farm ditch has a comparatively small section with shallow cutting depth, inaddition, there is lack of access road in the field, the excavation equipment with bulldozer or tracter-shovel (backhoe) type are not applicable because there are mostly adapted for the excavation of deep and wide section. Mini-backhoe with its bucket width not larger than 0. 3m, and width of blade not larger than 1. 00m seems to be more adaptable. About 80% of excavation of ditch section will be done by the machinery while the other 20% of excavation together with the finishing of the section are supposed to be done by man-power. The embankment of ditch section can be compacted by the crawler of backhoe when it is moving along the ditch for excavation. However, Lowland paddy field in the Monsoon Asia are made particulary in rain season, therefore, heavy machinery is not easy excavation for ditch. It is very important to know exact ground support power of the working site and select machines with corresponding ground pressure. Ground support power is variable subject to quality and water content of soil and therefore selection of machines should be made duly considering ground condition of the site at the time of construction works. Farm ditches dug and compacted by mannual labar are of poor quality and subject to destruction after one or two years of operation. On the other hand, excavation and compaction by bulldozer is not practical for ditches. Backboe is suitable for slope land, but this is required cycle time of bucket excavation and dumped out. If a small-scale farm ditch trencher adaptable to lowland paddy field is invented, such a machine could greatly accelerate the massive construction work envisaged in many countries and thus significantly speed up the most difficult part of irrigation development and management in Monsoon Asia.

• Journal of The Korean Society of Grassland and Forage Science
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• v.40 no.4
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• pp.251-258
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• 2020

To investigate the suitable growing area for Italian ryegrass (cv. Kowinearly and cv. Green-Call), we survey the different effects of climatic conditions on plant growth in the east (hereafter termed Yeongdong) and west (hereafter termed Yeongseo) of the passes in Gangwon Province. The Italian ryegrass was grown in Gangneung of Yeongdong and Wonju and Chuncheon of Yeongseo. The plants showed growth differences depending on the cultivated regions between before and after wintering. The Italian ryegrass for pre-wintering showed the relatively long length of plant height in Wonju. While, we observed the relatively tall plants for growing- and harvesting-period after wintering in Gangneung. The increased plant height in Gangneung was closely related to all climatic conditions for the growing period and mean- and lowest-temperature for the harvesting period, respectively. The amount of dry matter was 7,490 kg/ha for Kowinearly and 6,490 kg/ha for Green-Call in Gangneung, which has a higher yield than Chuncheon and Wonju. The relative yield index of dry matter was 77% (Kowinearly) and 78% (Green-Call) in Chuncheon and 84% (Kowinearly) and 71% (Green-Call) in Wonju compared to Gangneung as the standard region. Thus, we suggest that Chuncheon and Wonju are the possible areas for cultivation of Italian ryegrass, considering that Gangneung was the optimum growing area in Gangwon Province.

• Korean Journal of Breeding Science
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• v.51 no.3
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• pp.222-233
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• 2019

'Haepum' is a bacterial blight-resistant, medium maturing rice cultivar with high grain quality. It was derived from a cross between 'Iksan493' (cultivar name 'Jinbaek') and the F₁ cross between 'Iksan495' ('Dacheong') and 'Iksan496' ('Jungmo1005'). Of these three cultivars, 'Jinbaek' is a bacterial blight-resistant mid-late maturing rice cultivar with high grain quality, 'Dacheong' is a mid-late maturing rice cultivar with multiple resistance to disease and insects, and 'Jungmo1005' is a mid-late maturing rice cultivar with lodging tolerance. To develop fixed lines, the anther culture method was applied to F₁ plants. The cultivar 'Haepum' was selected using the pedigree method, yield trials, and local adaptability tests. The heading date of 'Haepum' was August 11^th, three days earlier than that of 'Nampyeong' cultivar. Haepum' is a cultivar tolerant to lodging and it has short culms. Due to its low rate of viviparous germination, 'Haepum' could be useful for preventing pre-harvest sprouting in cultivation of medium maturing rice in the southern plain area of Korea. 'Haepum' carries two bacterial blight resistance genes (Xa3 and xa5), and in our study, it exhibited high-level and broad-spectrum resistance against bacterial blight, including K3a, the most virulent race in Korea. 'Haepum' is also resistant to the rice stripe virus and moderately resistant to rice blast. The yield of 'Haepum' was similar to that of 'Nampyeong'. 'Haepum' showed excellent grain appearance and good taste of cooked rice, and therefore it could contribute to the development of bacterial blight-resistant rice cultivars of improved quality. 'Haepum' would be suitable for cultivation in the southern plain area of Korea as well as in bacterial blight-prone areas. (Registration No. 6068)

• Korean Journal of Agricultural and Forest Meteorology
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• v.23 no.4
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• pp.366-373
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• 2021

This study attempted to establish a field data-based write analysis standard by analyzing field observation data, which is non-linear data of southern garlic. Five regions, including Goheung, Namhae, Sinan, Changnyeong, and Haenam, were selected for analysis. Observation values for each observation station were extracted from the temperature data of farmland in the region through inverse distance weighted. Southern-type garlic production and temperature data were collected for 10 years, from 2010 to 2019. Local regression analysis (Kernel) of the obtained data was performed, and growth temperatures were analyzed, such as 0.8 (18.781℃), 0.9 (18.930℃), 1.0 (19.542℃), 1.1 (20.165℃), and 1.2 (21.042℃) depending on the bandwidth. The analyzed optimum temperature and the grown temperature (4℃/25℃) were applied to extract the growth temperature for each temperature by using the temperature response model analysis. Regression analysis and correlation analysis were performed between the analyzed growth temperature and production data. The coefficient of determination(R²) was analyzed as 0.325 to 0.438, and in the correlation analysis, the correlation coefficient of 0.57 to 0.66 was analyzed at the significance probability 0.001 level. Overall, as the bandwidth increased, the coefficient of determination was higher. However, in all analyses except bandwidth 1.0, it was analyzed that all variables were not used due to bias. The purpose of this study is to accommodate all data through non-linear data. It was analyzed that bandwidth 1.0 with a high coefficient of determination while accepting modeling as a whole is the most suitable.