• Economic and Environmental Geology
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• v.37 no.5
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• pp.555-568
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• 2004

The demand of aggregate resources in Korea has been increased with a rapid economic growth since the 1980s. About 25% of the total aggregate production is derived from riverine aggregates, 20% to 25% from marine sands, 40% to 45% from crushed aggregate and the rest 5% to 15% from old fluvial deposits. The abundance of crushed coarse aggregates varies in the uniform distribution of country, but in general it can be concentrated in the most densely populated areas, five main cities. Typical rock types of the Korean crushed stones are classified as plutonic rocks of 27%, metamorphic rocks of 32%, sedimentary rocks and volcanic rocks of 18%, respectively. The most abundant coarse aggregate used in the country is obtained from granite (25% of total) and subordinately gneiss (20%), sandstone (10%) and andesite (10%). Although rock types using as dimension stone are only fifteen, those as aggregate amount up to twenty nine rocks. These rocks consist of plutonic rocks such as granite, syenite, diorite, aplite, porphyry, felsite. dike and volcanic rocks such as rhyolite, andesite, trachyte, basalt, tuff, volcanic breccia and metamorphic rocks such as gneiss, schist, phyllite, slate, meld-sandstone, quartzite, hornfels, calc-silicate rock, amphibolite. And sandstone, shale, mudstone, conglomerate, limestone, breccia, chert are main aggregate sources in tile sedimentary rocks. The abundance of plutonic rocks is the highest in Chungcheongbuk-do, and decreases as the order of Jeollabuk-do, Gangwon-do and Gyeonggi-do. In Jeollanam-do, volcanic aggregates occupy above 50%, on the contrary sedimentary aggregates are above 50% in Gyeongsangnam-do.

• Korean Journal of Soil Science and Fertilizer
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• v.36 no.2
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• pp.66-71
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• 2003

This study was carried out to obtain basic data for selecting the applicable crops in reclaimed land and to provide guidelines for the rotation between paddy and upland cropping. Field experiment was conducted with six summer crops(garland chrysanthemum, young radish, small radish, kale, lettuce, red lettuce) at Dae-Ho reclaimed experiment plots in Dangjin province. Dry weights and plant heights of harvested crops were measured and soil chemical properties were analyzed. Plant height and dry weight decreased significantly with increasing soil saturation paste extract electrical conductivity(ECe) and sodium adsorption ratio(SAR). The threshold ECe of salt inhibition for six crops was less than $1dS\;m^{-1}$ for young radish and kale, greater than $4dS\;m^{-1}$ for garland chrysanthemum, and greater than $6dS\;m^{-1}$ for small radish, lettuce, and red lettuce. At higher ECe that inhibits crop growth, with every increase in $1dS\;m^{-1}$, dry weight index decreased by 3.35 for kale, 3.92 for small radish, 3.98 for young radish, 4.66 for lettuce, 7.57 for garland chrysanthemum, and 8.45% for red lettuce, respectively. The ECe causing 50% reduction of dry weight index was $18.9dS\;m^{-1}$ for small radish, $17.3dS\;m^{-1}$ for lettuce, $15.4dS\;m^{-1}$ for kale, $12.0dS\;m^{-1}$ for red lettuce, $11.3dS\;m^{-1}$ for young radish, and $11.0dS\;m^{-1}$ for garland chrysanthemum. Among the tested 6 summer crops through field experiment and in-situ survey, kale was proved to be a favorable vegetable crop at reclaimed tidal land.