Physical properties of greenhouse soils in Chungnam Province: current status and temporal changes from 2016 to 2024

다국어 초록 (Multilingual Abstract)

Greenhouse cultivation areas have been steadily expanding in South Korea. However, intensive tillage and excessive fertilizer use can deteriorate key soil physical properties, such as bulk density and structure. This study investigated temporal changes in soil physical properties at 37 greenhouse cultivation sites in Chungnam province over three monitoring cycles (2016, 2020, and 2024). Sampling sites were selected based on the regional distribution of major greenhouse-crops such as watermelon and tomato. The soils were classified into 18 soil series and 4 topographic types, with river alluvium being the most dominant (75.7%).
Soil texture in both topsoil and subsoil was dominated by silt loam, loam, and sandy loam. Among the topographies, river alluvium had the greatest average plowing depth (24.2 cm). In contrast, fluvio-marine deposits showed the lowest bulk density (1.08 Mg m-3) and the highest organic matter content. This suggests an inverse relationship between bulk density and organic matter. During the survey period, the plowing depth consistently met the recommended standard (>20 cm). However, a gradual decreasing trend was observed over time (from 26.7 cm to 23.0 cm). The bulk densities of both topsoil and subsoil remained within the appropriate standard (<1.6 Mg m-3 for sandy loam and 1.5 Mg m-3 for silty clay loam). However, the subsoil bulk density showed a steady increase over time(from 1.29 to 1.43 Mg m-3), indicating progressive soil compaction. Organic matter content declined in 2020 but slightly recovered by 2024. Overall, greenhouse soils in Chungnam are relatively well-maintained. However, the decline in plowing depth and the rise in subsoil compaction highlight the need for improved soil management. Practices such as deep tillage and regular application of organic amendments are recommended.