A study on the effects of the aggregate size on erosion by runoff and splash under simulated rainfall conditions.

The aim of this study was to determine the effect of different sized aggregates on runoff, sediment by runoff, and by splash with simulated rainfall. A soil sample which is known and well aggregated, was taken from the Agriculture Faculty’s Research Field of Ege University, and passed through different sieves (25-20 mm, 20-16 mm, 16-10 mm, 10-5 mm, 5-2 mm, 2-1 mm, and 1-0.2 mm) to establish 7 grouping. The sieved soil samples were placed in the erosion trays (30x30 cm), and simulated rainfall (65 mm h-1) was applied to the trays for 1 hour. According to the results of the simulated rainfall experiments, the aggregate sizes were found very effective on runoff (p= 0.0001; r= -0.420**), sediment by runoff (p= 0.0001; r= -0.980**), water resistance aggregate stability (p = 0.0001; r= 0.840**), mean weight diameter (p= 0.041; r= 0.550*), and aggregate index (p= 0.0001; r= 0.867**), significantly. No correlation was found between the aggregate sizes and sediment by splash linearly but polynomial relationships were found between the aggregate sizes and sediment by splash in the study.