Reclaimed Land in Korea and Its Soil Characteristics.

Reclaimed Land in Korea and Its Soil Characteristics Jang-Hee Lee,* Sun Kim, Whi-Jong Lee, Weon-Young Choi and Kyeong-Bo Lee Reclaimed Land Agriculture Research Division, NICS, RDA, Iksan, 570-080, Republic of Korea Abstract ˇˇWest-south coastline in Korean peninsula is a rias and has big difference between rise and fall of the tide. Reclaimed land with artificial dike has low groundwater table and poor vertical drainage. Reclaimed soil contain much Na and other salts, so to reduce salt content in soil to a level that crop can survive is important subject in agriculture. As high content of salt disturb nutrition absorption in plant, soil amelioration for early maturing on reclaimed land are needed. ˇˇThere are 1,641 reclaimed lands in south Korea and its total size is 135,100ha and 44,000ha is still under construction in 2009. Among them constructed lands by government is 94,911ha, by private is 40,189ha, and the Saemangeum reclaimed land is the biggest as 28,200ha that is still under construction in 2012. Reclaimed polder soil have low pore space ratio than mature upland and big bulk density. Geographically, reclaimed lands have high groundwater table and bad soil physical properties. Its desalinization by precipitation is not expected in most reclaimed land in Korea. When it precipitated, Na salt dispersed and combined with soil particle and filled pore space, which worsen soil vertical drainage. As it reclamation period longer in silt loam soil, clay in the surface used to be accumulated in subsoil and formed hardpan. Reclaimed land soil that had been influenced by sea have high contents of Na, Mg, Cl, SO4 but low of Ca, K, OM, P2O5, Fe. Chemical characteristics of newly reclaimed land soil in west coast mostly had high pH, organic matter lower than 1%. The pH values for upland soil were in the range of 5.7~5.9 and the lowest value was 5.5 of sampled in 1993. The organic matter content for upland soil was the highest as 25g kg-1 in 2005, while the available P2O5 content was lowest as 114mg kg-1 in the sampled from 1964 to 1968. ˇˇIn this paper, some soil amendments and amelioration method are suggested to reduce the period of soil desalinization in reclaimed land. Keywords: Reclaimed Land, Soil Amendment, Soil Chemical characteristics