Simulated rainfall setup
The experiments were conducted at the artificial rainfall simulation plots in the Science and Technology Park of Soil and Water Conservation, Institute of Soil and Water Conservation of Heilongjiang Province, Binxian County, located in the central region of the Mollisols region of Northeast China. A down-sprinkler rainfall simulator was used to apply rainfall; the system has three different nozzle sizes, which can be adjusted to rainfall intensities ranging from 30 to 200 mm h-1 (Shen et al., 2005). A removable waterproof canvas ceiling was used on top of the system to protect all experimental plots from natural rainfall, and a set of droppable canvases were used to surround the testing plots to eliminate wind impacts during the experiment (Figure 2 and 3).