Korean Journal of Soil Science and Fertilizer ISSN:0367-6315(Print) 2288-2162(Online) 한국토양비료학회 학회지

Typical reclaimed lands located in coastal areas including Saemangeum are not suitable for cultivation of upland crops due to a high salinity and groundwater levels and low nutrient contents. Therefore, for sustainable crop cultivation, it is necessary to soil salinity, water content, and nutrients that are necessary for development of land management for upland crops cultivation. In this study, we investigated physico-chemical characteristics of soils including pH, electrical conductivity (EC_1:5), organic matter contents, available phosphorus (Avail. P₂O₅), and exchangeable (Exch.) cations concentrations, as well as bulk density, hardness, and soil texture. Soil samples were collected from soil layers up to 120 cm at 20 cm interval of survey fields (80 ha) of Saemangeum reclaimed land. Groundwater levels and soil water contents were also monitored. The EC (0.14 - 0.51 dS m^-1) was lower than those of other reclaimed land in South Korea, indicating desalinization across 120 cm of soil depth, and pH (5.5 - 6.9) was also lower in accordance of the removal of non-acid cations through desalinization. Soil organic matter (1.5 - 5.2 g kg^-1), and nutrient (Avail. P₂O₅ 17.2 - 35.5 mg kg^-1 and Exch. calcium 0.8 - 1.0 cmol_c kg^-1) contents were lower than the standard levels for upland crop cultivation (Organic matter: 20 g kg^-1, Avail. P₂O₅: 300 mg kg^-1, Exch. calcium: 5 cmol_c kg^-1). However, the soil hardness (15.1 - 18.6 mm) was lower than the suitable level (21 mm) for crop cultivation. Meanwhile, water contents of top soil (0 - 20 cm) were greatly changed by rainfall pattern; in particular, the soil located near the coastal areas had a large rise in groundwater level during rainfall. Our study provide key information on the changes in soil physico-chemical properties across soil depth for Saemangeum reclaimed land, which was necessary for development of land management practices for cultivation of upland crops.

Groundwater levels and precipitation in investigated site (i.e., a, b, c and d, respectively) of Saemangeum reclaimed land during July to December 2022.