The change of soil physical quality depending on long-term land use types in a semi-arid ecosystem

In agricultural areas, soil physical quality controls critical properites for plant growth, such as aeration, soil water, and strength. This study investigated the impacts of different long-term land use types (LUTs) (natural pasture (control), kiwi fruit, cherry laurel, forage crops, soybean, and maize) on soil physical properties, such as structure stability index (SSI), bulk density (ρ_b), aeration capacity (AC), and Dexter's index (S-index). The long-term LUTs significantly affected all the examined soil properties (p < 0.01 or p < 0.001). Other soil physical properties, except for plant available water content, macroporosity, clay content, and silt content, changed statistically depending on soil sampling depths. The S-index values (≥ 0.050) obtained for all LUTs indicate very good physical quality or structural quality in the study area, but the S-index values decreased with the effect of LUTs compared to the natural pasture (control) land use. Different LUTs, such as cherry laurel, soybean, and maize land uses, have caused different structural degradation due to tillage practices. While the natural pasture (control) land use type revealed the best results regarding primarily soil organic carbon (SOC) and SSI, these values were lower in LUTs, where soil tillage is the most common, such as cherry laurel, soybean, and maize land use types. The results regarding S-index reveal that the soils in the study area will continue to be degraded as the impacts of the current LUTs continue. Therefore, for these soils in the future, there is a need for sustainable soil management practices that will protect the physical or structural quality and increase soil organic matter content.