• Korean Journal of Environmental Agriculture
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• v.37 no.2
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• pp.73-78
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• 2018

BACKGROUND: Soil salinity of reclaimed tidal land in Korea is highly important factor. High salinity is harmful to crop productivity. Jerusalem artichoke (Helianthus tuberosus L.) is known to be salt-tolerant and has high adaptability to diverse pedo-climatic conditions. The objective of this study was to assess the changes of soil properties and crop productivity according to salt concentration in the reclaimed tidal lands. METHODS AND RESULTS: Experimental sites were selected at Saemangeum ($35^{\circ}46^{\prime}N$, $126^{\circ}37^{\prime}E$) reclaimed tidal land, and their dominant soil series were Munpo (coarse loamy, mixed, non-acid, mesic, typic Fluvaquents). H. tuberosus L were collected from 12 locations across Korea. Tubers were planted at $75{\times}25cm$ with EC 2 to $7dS\;m^{-1}$. Soil samples were periodically collected from both 0~20 cm and 20~40 cm depths of each site. Soil salinity and soil moisture contents were varied depending on weather conditions. Soil electrical conductivity varied from 1.0 to $5.9dS\;m^{-1}$, and soil moisture contents varied from 9.2 to 28.7%. The white-colored tubers of H. tuberosus L. collected from 'Yeongwol-gun' exhibited the highest height (207 cm), followed by the white-colored tubers of H. tuberosus L. collected from 'Iksan-si'(202 cm). The white-colored tubers of H. tuberosus L. collected from 'GyeongJu-si' showed the highest yield (549 kg/10a). The purple-colored tubers of H. tuberosus L. collected from 'Yeongwol-gun' showed the highest yield (615 kg/10a). CONCLUSION: Our results indicate that the plant height and tuber yield did not appear to be correlated. Considering yield and inulin content, the GyeongJu-si seemed to be suitable as the white-colored tubers of H. tuberosus L. and the Yeongwol-gun seemed to be suitable as the purple-colored tubers of H. tuberosus L. in the reclaimed tidal lands. However, it is necessary to consider the relationship between the inulin content and the yield.

• Korean Journal of Heritage: History & Science
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• v.53 no.2
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• pp.110-139
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• 2020

Reclamation is the act of creating new lands by constructing dikes in offshore tidal flats to utilize them for various purposes, including the establishment of farmland to secure food for an increasing population. Based on the fact that reclamation has resulted in drastic changes in the environmental, economic, social, and cultural aspects of land expansion and development, population movement, and the formation of cities since ancient times, I reviewed the value of reclamation sites and addressed the issue of how to preserve and utilize them. "Reclamation culture" refers collectively to the recognition and concept system, behavior styles, and cultural products created by changes in the environment, and the tangible, intangible, and natural heritage generated directly and indirectly by reclamation is defined as "reclamation cultural heritage". It shows that the historical background of reclamation accords with prevailing trends, and that the reclamation sites possess cultural heritage value due to their historical, academic, and scarce characteristics. Numerous reclamation cultural heritage sites at the Gwangwhal and Gyehwa dikes are on the verge of being destroyed, with their original function having ended after the construction of Saemangeum Sea Wall. I propose measures to preserve these under the principle that utilization is based on the basic premise of conservation. First of all, modern and contemporary reclamation sites must necessarily be designated and managed as registered cultural properties, local cultural heritage, future heritage, and agricultural heritage. In particular, as it has been confirmed that reclamation sites created after the Goryeo and Joseon dynasties and the 1950s have not been designated as cultural heritage sites. It is necessary to review the characteristics and values of such reclamation sites through a full survey of national reclamation data. Effective and sustainable utilization of reclamation cultural heritage, which has not been acknowledged in the past due to its close relationship with our lives, is necessary to search for hidden stories found within that heritage, to organize governance for the efficient use of reclamation resources, and to build a museum to collect and display the history and culture of the reclaimed areas. Finally, through links with countries with experience in reclamation, we will be able to cope jointly with international issues such as those pertaining to society, culture, and environment, and would be able to implement various projects to further the advancement of human beings.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.10a
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• pp.100-100
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• 2018

Zoysia japonica Steud.(Zj) is a typical warm-season Korean lawn grass, which is used in many places such as river banks, roadside and soccer fields in Korea. Recently, it has also been used in school yards and the Saemangeum reclaimed land to reduce water pollution. Although the cultivated area of turfgrass is steadily increasing worldwide, it grows fast requiring frequent mowing and is difficult to grow in shady areas and the cold region. Therefore this study aims searching for useful gene(s) to develop abiotic stress tolerant and dwarf zoysiagrass. We isolated Ycf4 gene based on the sequence from Oryza sativa Japonica through RT-PCR and RACE PCR. Ultimately, open reading frame (ORF) of ZjYcf4 was 558bp long, encoding a protein of 186 amino acid residues. NCBI blast results showed that the ZjYcf4 protein is evolutionarily closely related to Ycf4 protein from Zoysia macrantha and Setaria italica (100% and 98%, respectively). To determine whether ZjYcf4 was involved in environmental stress in wild-type zoysiagrass, expression patterns of the gene were analyzed by real-time PCR under salt, cold and dark conditions. They were analyzed after each stress treatment for 3 hours. In salt and cold stresses, the expression was higher compared to control (3-fold and 1.5-fold, respectively), although there was a 1.6-fold decrease in expression under dark stress treatment. As reported previously, we suggest that ZjYcf4 gene affects abiotic stress such as salt, cold and dark.

• Korean Journal of Agricultural Science
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• v.32 no.2
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• pp.107-126
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• 2005

The most limited production resource in Korea is land. During the period from 1995 to 2002, annual farm land area of 17,600ha have been converted to urban and industrial land. The self-sufficiency rate of rice, Korean staple food, is expected to be decreased from 97.5% in 2003 to 60-70% in 2020. Under such conditions, this study is aimed at first identifying multi-functional benefits of the reclamation projects such as agricultural production, industrial water supply, urban land supply, transportation effects, sightseeing effects and environmental values with and without the projects. To carry out the objectives, three existing tideland reclamation projects such as Daeho, Kumgang and Yongsangang irrigation project stage II were evaluated and Saemangeum tideland reclamation project which was jointly revaluated by environmental NGO and Govn't appointed specialists in 2000 was reviewed. According to this study results, tide land reclamation projects were showed financially and economically feasible and environmentally sustainable. The joint cost like estuary dam should be allocated based on the multi-functional benefits of the projects. To allocate the joint cost, legal and institutional improvement should adapt the joint cost allocation method as the specific cost-remaining benefit method. Korea has more than 402,000 ha of tidal flat of which 76,396ha have been reclaimed in 2003. To meet food security and to cope with shortage of land, phil-environmental reclamation projects should be continuously implemented and necessary tidal flats for protecting environmental ecosystem should be remained according to the detail survey results of reclaimable resources.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.3
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• pp.444-450
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• 2012

The physical and chemical properties of soil in the Mangyeong and Dongjin river basin had been investigated in order to establish the most optimum soil improvement plan on the reclaimed land. The total soil area by reclamation in Saemangeum basin is 113,971 ha. The classification by the distribution of soil series and soil texture is as following. 13 soil series including Chonnam, Buyong and Chonbuk series are period-unknown areas. Regarding the soil texture, they are fine silty ~ clayey very fine. From 1920s to 1960s, Mangyeong, Gwanghwal and Chonbuk series had coarse silty textured soil. After the 1970s, Mangyeong, Gwanghwal, Munpo, Yeompo, Poseung, Gapo and Hasa series have more sandy soil ~ moderately coarse loamy textured soil. Regarding the chemical properties, the concentrations of EC, Exch. $K^+$, $Mg^{2+}$, $Na^+$ and pH are high regardless of the time of reclamation. On the other hand, organic matter (OM) of top soil were 3.3~16.1 g $kg^{-1}$. The organic matter contents were very low though the soil had been farmed for a long time. Furthermore, the deep soil had almost no organic matter with 5.6~1.1 g $kg^{-1}$. The reason is believed that there had not been any movement of OM and clay because pressure or induced pans had been formed by large agricultural machineries and poor vertical drain. Regarding the forming of illuvial horizon (B layer) which tells the development extent of soil, only in the Hwapo reclaimed area where rice had been cultivated for past 90 years, Fe and Mn from top soil are deposited at underground 20~30 cm with 7~8 cm thickness by the movement of clay. It is believed that it had been possible because the earthiness is silty clay loam soil with relatively high content of clay. The soils are soil with concern of damage from sea water, soil on flimsy ground and sandy soil. Therefore, soil improvement for stable crop production can be expected; if the water table would be lowered by subsurface drainage, the water permeability would be enhanced by gypsum and organic matter, and the sandy soil would be replaced by red soil with high content of clay.

• Korean Journal of Weed Science
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• v.32 no.1
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• pp.1-9
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• 2012

This study was conducted to survey vegetation changes and soil characteristics in Saemangeum new reclaimed tidal land. Soil salinity in border area to tidal land was 22.3 dS $m^{-1}$ but showed 1.1~3.44 dS $m^{-1}$ over the distance of 2 km from border line. The vascular plants in survey sites were recorded as total 26 taxa in 6 families. The frequency of species appearance of Aster tripolium, A. subulatus var. sandwicensis were highest by 61.5 and that of Phragmites communis, Puccinellia nipponica were 53.8. The almost vegetations occurred in the patch which range of soil salinity 14 dS $m^{-1}$ were halophytes as Salicornia europaea, Suaeda asparagoides, S. japonica. As lowed soil salinity as 6.7 dS $m^{-1}$, mixed vegetation of halophytes with P. communis, P. nipponica, Carex pumila were occurred. Dominant species in the range of 3.0 dS $m^{-1}$ area were A. subulatus var. sandwicensis, P. communis, Echinochloa spp., Zoysia sinica and Conyza canadensis. Biomass production was the highest in the area of dominant vegetation with P. communis, and mixed zone with P. communis and Aeschynomene indica are followed. The correlation between vegetation biomass and soil salinity, soil pH and dominance index of vegetation were negative. But that of vegetation biomass and soil organic content were positive.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.58 no.2
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• pp.85-90
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• 2013

This study was conducted to examine the basis for the information to select the suitable potato varieties grown in new reclaimed land. The potatoes of five varieties were planted in the port with 4 different electrical conductivities of saturated extracts of soil taken the Saemangeum reclamation area, which was made of non-treatment salt and three concentrations of salt treatment, 1.6 dS $m^{-1}$, 3.2 dS $m^{-1}$, 4.8 dS $m^{-1}$, respectively. All of the potato varieties were uniformly emerged without missing plant in all treatment groups, even 4.8 dS $m^{-1}$ treatment group. According to the salt concentration of soil, required date to the emergence of the potato comparing to non-treatment salt was delayed 3-4 days in 1.6 dS $m^{-1}$, 6-10 days in 3.2 dS $m^{-1}$, 7-13 days in 4.8 dS $m^{-1}$, respectively, and the number of its branch decreased by 14-58% comparing to non-treatment salt depending on varieties. Since the increase of the salt concentration of the soil was more serious the decrease of the number of its branch, but plant height tended to increase when branch number per plant was small, which was depending on more number of its branch than salt concentration. Fresh tuber yield of potato comparing to non-treatment salt were decrease 33.7% in 1.6 dS $m^{-1}$, 59.5% in 3.2 dS $m^{-1}$, 79.3% 7-13 days in 4.8 dS $m^{-1}$, respectively. The threshold EC starting the growth inhibition of fresh weight decreased was 1.2 dS $m^{-1}$ for Chudong, 1.8 $m^{-1}$ for Chubeak, 1.9 $m^{-1}$ for Chugang and Chuyeong, and 2.0 $m^{-1}$ for Sumi, and EC which decreased 50% of dry weight index was 2.4 dS $m^{-1}$ for Chubaek, 2.45 dS $m^{-1}$ for Chudong, 2.81 dS $m^{-1}$ for Chugang, 3.03 dS $m^{-1}$ for Chuyeong, and 3.29 dS $m^{-1}$ for Sumi. The present results suggest that Sumi is considered to the suitable potato variety grown on saline soils.

• Journal of the Korean Geosynthetics Society
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• v.14 no.4
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• pp.59-77
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• 2015

In order to meet the new requirements for landfill materials, this study planned a study to apply mixed soil of mixing bottom ash and coastal dredged soil to the dredged ground. Coal ash generated from thermal power plant is divided into fly ash and bottom ash. In the case of fly ash, many studies have been conducted because small particles causes permeability coefficient to be small during recycling so no problem has been raised in the environmental area but the utilization of bottom ash has been limited because environmental problems have been raised during recycling due to its larger particle size and greater permeability coefficient. According to recently published studies, however, the results of the study that conducted the water analysis of leachate generated in the ground improvement section using bottom ash showed that heavy metal contamination levels were found to be within the reference value and no significant environmental problems were found so utilization of bottom ash is evaluated to increase significantly in the future. This bottom ash has the particle size of sand and only transportation costs need to be considered when providing materials because the majority has been disposed and it is judged as the most suitable material in dredging landfill in the economic aspect because most thermal power plants are located in the coast and transportation costs can be reduced by ship. Also, research on mixed soil that can maximize the effect of the construction period and construction cost savings than dredged soil is determined as needed because the demand for coastal dredging reclamation is increasing such as Saemangeum project etc. Therefore, we studied self-weight consolidation characteristics depending on sample processing and mixing method of mixed soil by carrying out interior self-weight consolidation experiments on mixed soil of mixing bottom ash and Kaolinite according to the new development needs of recent coastal reclaimed ground and these result findings are expected to be used as basic data when applying the large coastal dredged ground in the future.