Study of Rainfall Processes in Calcareous Soils Aggregates under Laboratory Conditions in NW Zanjan, Iran

Rainfall erosion processes a long with the rainfall characteristics can be affected by soil properties. The study was conducted to investigate the susceptibility of the aggregates in different soil textures to the rainfall erosion processes. The experiment was done on thirty soil samples recognized in four soil textures with different replications as the completely randomized design. Ninety boxes were filled with aggregates (6-8 mm) and were exposed to the simulated rainfall for 30 minutes. Results indicated that there were significant differences among different soil textures in the aggregate breakdown (P< 0.001), soil compaction (P< 0.001), and soil particles splash (P< 0.01). The highest aggregate breakdown was observed in sandy loam soils, whereas the highest soil compaction and soil particles splash occurred in clay loam soils. The aggregate breakdown was significantly affected by silt particles (r= -0.63, P<0.01) and clay particles (r= -0.70, P<0.01). Nevertheless, the soil compaction and particles splash were significantly increased by silt and clay particles. Sand contrary to other soil particles (silt and clay) had different effect on the rainfall erosion processes.