干旱区生态环境知识资源中心

Monitoring of soil properties is a significant process and plays an important role about how it can be used sustainably. This study was performed in a local area in Sawda Mountains KSA to map out some soil properties and assess their variability within the area under different land cover. Soil sampling was carried out in four different sites using the grid sampling technique. Ten samples were collected in each location within a 10 by 10 km area; soil was sampled at 0-30-cm depth. The soil samples were air-dried, crushed, and passed through a 2-mm sieve before analyzing it for pH, EC, CaCO3, organic matter contents, and bulk density. The thematic maps of these characteristics were produced using ArcGIS 10.0 software. Finally, the land degradation was assessed using three factors: soil salinization, compaction, and edibility. The obtained results showed that the high risk of soil compaction, salinization, and erodibility occupied an area 5.6 ha (17.5%), 3.7 ha (11.54%), and 8.1 ha (25.3%), respectively, in the surface soil layer. The land degradation risk in the study area due to salinization was low to high; however, the degree of soil compaction was moderate to very high. The K-factor (soil erodibility) in the area ranged between 0.1 and 0.35 Mg h MJ(-1) mm(-1), and most of the study area was located in moderate to high erodibility classes.