The independent effects of hedgerow or grass ditches on the migration of runoff, sediment and nutrients are well known; however, the effects of combined hedgerow–grass ditch systems have rarely been assessed. Vegetation stem diameter (VSD) is an essential variable that changes the effectiveness of a hedgerow–grass ditch system in reducing runoff and sediment yield on sloping lands. A hedgerow–grass ditch system was simulated to interpret the effects of varied VSDs [i.e., 0 (control), 0.1, 0.2, 0.4 and 0.8 cm] in hedgerow on runoff and sediment yield by laboratory rainfall simulation. Compared to the control, the time to runoff initiation presented a 43.3% delay in 0.8 cm VSD (p p p p < 0.05). Our results have great significance for creating strategies for soil and water conservation on sloping lands.
