Prevalence, causes, and consequences of agricultural land abandonment: A case study in the Region of Murcia, Spain

•Abandoned terraces, particularly those in loamy soils, are prone to severe erosion due to piping.•The physical and chemical analyses of soils reveal detrimental changes that exacerbate erosion processes.•There is a critical need for effective land use planning and management, particularly in semi-arid regions such as Murcia (Spain). Agricultural land abandonment has received increasing attention from the scientific community and decision makers in recent years. In this study, we aimed to identify the current status of agricultural land abandonment in Europe, investigate its main causes and consequences, and propose management solutions based on future projections. We selected the Region of Murcia (RM) in southeastern Spain as the study area as it has been identified as a hotspot of agricultural land abandonment. A large number of areas with severe erosion (gullies and piping) attributed to abandonment have been identified in the Neogene and Quaternary basins. Morphometric analyses of various fields and estimates of soil loss were performed in 57 abandoned land areas in the RM. Additionally, physical and chemical soil analyses were performed in 15 selected areas. The results showed that abandoned crop terraces in loam soil promote piping processes owing to their flat surfaces and the formation of a hydraulic gradient. Furthermore, soils with a poor structure, fine texture, and low organic matter content are vulnerable to erosion processes. Additionally, increased exchange sodium percentage (ESP), electrical conductivity (EC), sodium absorption ratio (SAR), and soluble sodium percentage (SSP) contribute to these processes. The results of this study confirmed the detrimental effects of abandoning agricultural land. We found that multiple contributing factors led to severe erosion on abandoned land in the RM. Therefore, efficient land use planning and management are required, especially for land abandonment in Neogene and Quaternary basins in semi-arid regions.