• Korean Journal of Environmental Agriculture
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• v.38 no.4
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• pp.273-280
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• 2019

BACKGROUND: The reclaimed lands for agricultural use managed by the Korean government is consisted of 17,145 hectares of lands under construction and 13,384 hectares of completed lands. In order to utilize these reclaimed lands as competitive agricultural complexes, the government is preparing to develop comprehensive development plans for multiple purposes. For rational land-use planning and soil management, information of the soil chemical properties is necessary. METHODS AND RESULTS: From 2013 to 2016, soil samples were collected from 85 representative sampling sites of the reclaimed lands and analyzed for soil chemical properties including electric conductivity (EC), pH, soil organic matter (SOM), and nutrients. The annual mean soil EC ranged from 5.1 to 8.3 dS m^-1 and have continued to decrease over the years (estimation equation with EC as dependent and year as independent variable was y =0.0736x² - 1.4985x + 9.8305, R² = 0.9753). The pH ranged from 7.3 to 7.6, which was higher than the optimum range (5.5~7.0) for agricultural soils. Soil organic matter (8 to 11 g kg^-1) was lower level than the optimum range (20~30 kg^-1). Available silicate (Av.SiO₂) ranged from 169 to 229 mg kg^-1, which was close to the minimum content (≥157 mg kg^-1) for rice paddy field. Available phosphate (Av.P₂O₅) content (24~39 mg kg^-1) was lower than the optimum range (80~120 mg kg^-1) for rice paddy field. CONCLUSION: For efficient agricultural use of reclaimed lands under government management, our results suggest that the application of organic matter and supplying deficient nutrients as well as desalinization is required.

• Korean Journal of Environmental Agriculture
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• v.37 no.3
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• pp.197-206
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• 2018

BACKGROUND: The present study aimed to examine the crops capable of growing and adapting to the external environment and various stresses of reclaimed agriculture land for the development of high value-added agricultural utilization technology based on reclaimed land through standardization and empirical study of cultivation environment for cultivating crops. METHODS AND RESULTS: Two crops namely turnips and beets were selected for the salt tolerance test of soil environmental conditions on reclaimed land. Turnip and beet seedlings were planted on the soil collected at the 'Seokmun' reclaimed land. There are five treatments such as non-treatment, 1.0, 2.0 (control), 4.0 and $8.0dS{\cdot}m^{-1}$ of EC. The contents of betacyanin in beet roots was highest in control and decreased with increasing salt concentration. The GSL contents in the turnip roots waswere highest at EC 2.0 and decreased with increasing salt concentration, whereas those in turnip leaves waswere high both in the non-treated control and atthe EC 1.0-treatment. But, tThere was, however, no statistical differences among the treatments. CONCLUSION: The degree of salt tolerance of crops was examined, and the limit EC iswas expected to be $3.0{\sim}4.0dS{\cdot}m^{-1}$ as reported to date. If the soil improvement is performed and irrigation systems are used in the actual reclaimed land, the EC of supplied irrigation will be low, and desalination effecttreatment by the lower EC of the supplied irrigation on the soil will lead to more favorable soil condition of the rhizosphere and cultivation environment offor the crops than those in the port experiment. Therefore, monitoring the salinity, water content and ground water level will enable prediction of the rhizosphere environment, and setting up irrigation management and supplying irrigation will lead to crop cultivation results that are close to normal.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.5
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• pp.872-877
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• 2011

Cultivation of Korea ginseng in newly reclaimed and paddy-converted fields has been increasing, and evaluation of organic amendment effectiveness is needed in the two soil types. Soil organisms influence organic matter decomposition, and their responses to applications of organic matter were studied. De-oiled cake and compost were applied at $20Mg\;ha^{-1}$ and $40Mg\;ha^{-1}$ in both soil types. Changes in microflora were assessed by analyzing phospholipid fatty acid (PLFA). The abundance of nematodes and microarthropods was measured. Microbial PLFA indicators for microorganisms and microarthropod abundance were greater in reclaimed upland than in paddy-converted soil. There were few differences in the microflora and fauna of reclaimed uplands, regardless of treatment. In paddy-converted soil, the abundance of Oribatida was increased by the application of compost at $20Mg\;ha^{-1}$ and was correlated with PLFA indicators of fungi. The results suggested a minimal influence of organic amendments in reclaimed upland, because the organic matter content and abundance of soil organisms are low in mineral soils. In paddy-converted soil, the effects of organic amendment differ among different soil organisms, and soil properties are important mediators of the effect.

• Korean Journal of Agricultural Science
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• v.38 no.2
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• pp.301-307
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• 2011

In this article, we reviewed properties of reclaimed tidal soil and fate of nitrogen in its soil. The results were summarized as followings. Most of the soil derived from the fluvio-marine deposit were silly textured soils. The EC of the Saemanguem soil were ranged from 14.7 to 33.9 dS $m^{-1}$, pH was 7.7. The organic matter content was low with 1.5 g $kg^{-1}$. The cation exchange capacity was 7.2 cmol $kg^{-1}$ and exchangeable sodium percent was high with range 45.1 % to 56.2%. High sodium concentration caused poor drainage. The salinity significantly affects efficiency of N fertilizer in reclaimed tidal soil.

• Journal of the Korean GEO-environmental Society
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• v.18 no.2
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• pp.59-65
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• 2017

The costal reclamation construction is for making reclaimed land by dredging marine clay with seawater, and then bringing the dredged soil into the reclaimed land. During the process, the dredged soil in the reclaimed land undergoes the sedimentation-consolidation process. Among the processes, the consolidation is a very critical factor when planning reclaimed land because of its requiring time and settlement. In order to predict the requiring time and settlement, the Column test, which was suggested by Yano, has been usually used in the nation. However, the test method needs a very long time to identify the characteristic of sedimentation-consolidation of dredged soil. Therefore, in this study, in order to supplement the weakness of the Column test which needs such a long time, and in order to identify the characteristic of the sedimentation-consolidation for dredged soil in a short time, the Geo-centrifuge test was examined as an alternative method. The result considered that Geo-centrifuge test would be useful to identify the characteristic of sedimentation-consolidation for dredged soil efficiently.

• Journal of Industrial Technology
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• v.20 no.A
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• pp.101-111
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• 2000

This research is results of experimental and numerical works on characteristic of strength increase and bearing capacity in dredged and reclaimed soil due to desiccation shrinkage. For a soil sampled from southern coastal area in Korea, basic soil property tests and standard consolidation test with falling head permeability tests were carried out to obtain consolidational characteristics of soil. Double cone penetration test, laboratory vane test and unconfined compression test were also performed to investigate the change of shear strength with degree of desiccation. Model tests were performed in 1G environment and 30G level artificially accelerated condition by using the centrifuge model test facilities to investigate the bearing capacity of desiccated ground. Test results were analyzed by using the theoretical and load-settlement characteristics method proposed by Meyehof & Hanna(1978). On the other hands, the numerical technique, using the finite strain consolidation theory considering the effect of desiccation was used to estimate the appropriate time of using heavy construction equipments in field with respect to strength increase due to desiccation.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.10a
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• pp.1717-1726
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• 2008

Vibration triaxial compression test was put in influence for liquefaction strength of fine grained soil of dredged and reclaimed ground and consideration for fine fraction content, relative density, overconsolidation ratio and plasticity index in this study. By the results of these test, the liquefaction strength increased with fine fraction content and the relative density, overconsolidation ratio incresed with liquefaction strength too. However, in the case of nonplastic silt was the smalist liquefaction strength which influenced by dilatancy and interlocking when silt content was 34.7%(average grading 0.12mm). Therefore, liquefaction strength of fine grained soil of dredged and reclaimed ground increased with fine fraction content so it will help to make lower liquefaction.

• Korean Journal of Soil Science and Fertilizer
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• v.42 no.6
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• pp.415-422
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• 2009

Effect of soil salinity variation on the growth of barley, rye and oat was studied at the Hwaong, Iweon and Yeongsangang reclaimed lands in the western seaside of Korea. Soil salinity variation and soil EC were very high for crops to be killed or to be brought serious growth retardation during the growing season at the Iweon and Hwaong reclaimed lands, but fully low not to bring growth retardation at the Yeongsangang reclaimed land. Relation between soil salinity and crop growth and yield was well expressed as logarithmic function. Surface soil EC to reach at 50% of seed-emergence reduction was estimated $6.5dS\;m^{-1}$ for barley and $5.1dS\;m^{-1}$ for rye and oat by logarithmic function. In addition, surface soil EC to reach at 50% of grain yield reduction to the best growth in the experimental site was estimated $5.6dS\;m^{-1}$ for barley, $5.8dS\;m^{-1}$ for rye and $5.7dS\;m^{-1}$ for oat, while soil EC to reach at 50% of dry matter reduction was estimated $5.5dS\;m^{-1}$ for barley, $6.2dS\;m^{-1}$ for rye and $5.8dS\;m^{-1}$ for oat by logarithmic function. Grain yield of barley, rye and oat was 395, 164 and $325kg\;10a^{-1}$ in the Yeongsangang reclaimed lands naturally controlled below condition of $6dS\;m^{-1}$ of soil EC, but no harvest was obtained in the Hwaong and Iweon reclaimed land because of high salinity more than $15dS\;m^{-1}$ in maximum soil EC during growing period. Consequentially, it was concluded that soil salinity must be controlled below $6dS\;m^{-1}$ for good growth and high yield of winter barley, rye and oat in the reclaimed land in Korea.

• Korean Journal of Organic Agriculture
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• v.24 no.3
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• pp.583-598
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• 2016

Salted-affected soil is a major environmental constraint with severe negative impacts on agricultural productivity and sustainability in reclaimed tidelands. This review focuses on the phytoremediation of reclaimed tidelands. We address the process of phytoremediation of these soils, comparison of phytoremediation with other amelioration approaches, driving forces contributing to the process, selection of phytoremediation crops, and the role of cropping in securing environmental integrity under salt-affected soils.

• Korean Journal of Environment and Ecology
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• v.16 no.1
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• pp.10-21
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• 2002

This study was intended to investigate injury rates of landscape trees planted in the reclaimed seaside areas and to analyse their causes in planting environment. The planting environment such as soil properties, reclaimed depth of soil, soil hardness, salt consistency of soil, and drainage system were surveyed in 8 reclaimed seaside areas in the middle and southern regions of the country. Injury rates of 42 species, 1,233 trees and growth of branches in 6 species. 130 trees were measured and analysed to fond out salt-resistant trees in the reclaimed lands. The results of the survey are as follows; the average injury rate of evergreen trees was 32%. which was much lower than that of deciduous trees as 52%. The lower injured trees in the 8 reclaimed lands were Pinus thunbergii, Pinus parvinora. Juniperus chinensis 'Kaizuka', Pinus koraiensis, Acer trifdum, Koelreuteria paniculata and Metasequoia glyptostroboides. The higher injured trees were Acer palmatum, Magnolia kobus. Lagerstroemia indica, Diospiros kaki, Cercidiphyllum japonicum, Sorbus commixta, Prunus yedoensis, Pinus desinora, Chaenomeles sinensis, Albizzia julibrissin and Zelkowa serrata. At least the mounding of 1.7m depth of soil is needed from the tidal saline soil to the roots of trees to protect trees from salt injury Roots of trees were found to have infiltrated to 0.77m under the soil of which solidity was over 4.5kg/㎥. And 22 of total 25 soils were acid from pH 3.72 to pH 5.85. Injury rate of trees was much higher when they were detached from the sea, and planted on the drainage.