Scale effect on runoff and soil loss control using rice straw mulch under laboratory conditions

Amendments can control the runoff and soil loss by protecting the soil surface. However, scale effects on runoff and soil loss control have not been considered yet. The present study has been formulated to determine the efficiency of two plot sizes of 6 and 0.25 m super(2) covered by 0.5 kg m super(-2) of straw mulch with regard to changing the time to runoff, runoff coefficient, sediment concentration and soil loss under laboratory conditions. The study used a sandyloam soil taken from summer rangeland, Alborz Mountains, northern Iran, and was conducted under simulated rainfall intensities of 50 and 90 mm h super(-1) and in three replicates. The maximum change in soil loss at the intensities of both 50 and 90 mm h super(-1) occurred in the 0.25 m super(2) plot, with 100%, whereas in the 6 m super(2) plot, decreasing rates of soil loss for the intensities of both 50 and 90 mm h super(-1) were 46.74 and 63.24%, respectively.