Uniform rainfall at a constant intensity was applied for 1 h to the experimental plots. Runoff samples were collected at 2.5 min intervals until the rainfall was stopped and then was continuously recorded at 3.0 min intervals up to 90 min. Thereafter, the clear water was removed from the collected runoff by pipette, and the remaining sediment was oven-dried at 105 °C for 24 h. Next, the tested soil in the plot was left for at least 2 d before the next test. The tested soil was raked to loosen material from the previous testing. Before each testing, about 5–10 cm of surface soil was removed and replaced by fresh soil.