To investigate the effects of extreme soil erosion on physical and chemical properties of soil and crop yield

simulated experiments were conducted in topsoil (30 cm)

transition layer (40 cm) and parent material layer (＞70 cm) of Mollisols farmlands. Treatments including 70 cm topsoil removal

30 cm topsoil removal

no eroded soil

30 cm sediment deposition and 70 cm sediment deposition were set respectively. The results showed that compared with no eroded soil

soil bulk densities

soil mass water contents

soil water storages of the other four treatments were all significantly increased in tillage layer (0—20 cm)

while soil porosities

contents of soil water stable aggregates were greater than 0.25 mm

mean weight diameters

geometric mean diameters

field capacities

saturated moistures and soil nutrient contents of the four treatments were all significantly decreased. Furthermore

compared with no eroded soil

corn yields of the treatments of 30 cm and 70 cm soil removal reduced by 42.1% and 52.6%

respectively. There was no significant difference in corn yield between no eroded soil and 30 cm sediment deposition. Corn yield of the treatment of 70 sediment deposition significantly decreased by 12.4%. Thus

extreme soil erosion

no matter topsoil removal or sediment deposition

will lead to the decline of soil quality

reduce soil fertilizer supply and conservation ability

then reduce corn yield.