Straw Mulching Effect on Splash Erosion, Runoff, and Sediment Yield from Eroded Plots

Land surface cover affects runoff generation and soil loss processes. Splash erosion occurs by the impact of raindrops on the soil surface. As a result of this process, raindrops detach soil particles, destroy soil structure, and finally, increase runoff and erosion. Amendments improve and reinforce soil aggregates and some physical barriers against raindrop impacts and runoff. The present research was an attempt to determine the efficiency of straw mulch applied at a rate of 0.5 g m−2 in changing the runoff commencement time, runoff amount, splash erosion, and sediment yield from eroded mid‐sized plots at different rainfall intensities under laboratory conditions. The research was conducted on a sandy loam soil taken from summer rangeland in the Alborz Mountains, northern Iran, with simulated rainfall intensities of 30, 50, 70, and 90 mm h−1 and a slope of 30% in three replicates. The collected data from 36 splash cups showed that the straw mulch played an effective role in reducing the splash erosion in both up and down directions, with the maximum reduction occurring at a rainfall intensity of 70 mm h−1. The results of the research also showed that the straw mulch had a significant effect in changing runoff and soil erosion characteristics at a confidence level of 99%. The maximum increase in runoff commencement time (110.10%) was observed for the rainfall intensity of 90 mm h−1. The runoff coefficient had a maximum reduction at rainfall intensities of 30 and 90 mm h−1. The maximum decrease in sediment yield (63.24%) also occurred at the rainfall intensity of 90 mm h−1.