a C, FT, R, R + FT stand for the control, freeze-thaw, root system and root system + freeze-thaw treatments, respectively.
b Lowercase letters in this line indicate a significant difference for different treatments of sand soil at P< 0.05. The capital letters in this line indicate a significant difference for different treatments of loessal soil atP < 0.05.
Table 3 Regression relationships between soil detachment capacity (SDC) and hydraulic parameters of sand soil