Investigating the effects of antecedent rainfall on splash erosion in a Marl soil using rainfall simulator

Splash erosion is one of the most important kinds of water erosion. Splash of soil particles may affected by some factors especially antecedent rainfall event. Up to now, there isn’t any study on the effects of antecedent rainfall on splash erosion in the next rainfall. This study was conducted to investigate effect of the antecedent rainfall on the particles splash in a marl soil. Toward this, aggregates with a diameter of 6-8mm were taken of a marl soils under fallow condition in 2016. Aggregate were packed in 24 boxes with 30cm× 40cm dimensions and 30cm depth to investigate effect of eight rainfall durations levels at three replications. Simulated rainfall was applied to soil samples with eight durations (0, 7, 14, 21, 28, 35, 42 and 49 min). Aggregate breakdown and soil water content were determined in the soil samples after one day. After one day, soil boxes were placed under the same rainfall with a constant intensity of 40 mm h-1 for 15 min. Based on results, duration of antecedent rainfall significantly affected on the aggregate breakdown and increasing soil water content. The longest rainfall duration (49 min) appeared the highest aggregate breakdown (21.72%) as well as soil moisture content (29.08%).The amount of splash erosion in the next rain event were significantly influenced by the two soil variables changed by the antecedent rainfall i.e. aggregate breakdown (P