Monitoring soil characteristics of the Saemangeum reclaimed agricultural soils for enhancing upland crop productivity

Reclaimed agricultural soils, which accounts for 7.1% (112,464 ha) of Korea's agricultural land, is increasingly required to support upland crop cultivation amid national efforts to enhance grain self-sufficiency.However, both low-fertility and high-salinity of these soils significantly hinder crop productivity.This study aimed to assess the physicochemical properties of reclaimed agricultural soils from 69 locations in the Saemangeum reclaimed area to provide foundational documents for improving upland crop productivity.Soil samples were collected in 10 cm increments down to a 70 cm depth and analyzed for bulk density, moisture content, porosity, pH, electrical conductivity (EC), and exchangeable cations (i.e., K + , Ca 2+ , Mg 2+ , and Na + ) content.The averaged bulk density (1.44 gcm -3 ) and porosity (45.76%) at a depth of 0 -30 cm met the appropriate range for upland crop cultivation, although localized compaction requires attention.Gravimetric and volumetric moisture contents exceeded the optimal standard, ranging from 20 to 25%, suggesting the need for periodic monitoring.Soil pH and EC values increased with the deepening of soil depth but generally remained within sustainable ranges (pH, 6.0 -7.0; EC, 2.0 dSm -1 ).However, the Saemangeum reclaimed agricultural soils had the excessive K + and Mg 2+ concentrations and insufficient Ca 2+ level, which may impair crop productivity.These findings highlight the necessity of targeted soil amelioration strategies, especially Ca 2+ supplementation and Na + mitigation, for sustainable crop cultivation in reclaimed agricultural soils.