Mechanical stability of aggregate is a key factor influencing soil resistance to erosion. To investigate the variations of aggregate tensile strength for zonal soils and their stabilization mechanisms

aggregates of different sizes (1~2

2~3

3~5 and 5~10 mm) for six typical zonal soils (Cinnamon soil

Yellow-cinnamon soils

Brownish red soils

Red soils

Latosolic red soils and Latosols) in central-southern China were selected. In the study

the tensile strength and their relationships with soil physicochemical properties were examined. Main results were shown as follows: (1) With the increase of hydrothermal condition

soil pH and kaolinite content gradually decreased from north to south

while opposite trends were displayed in free iron (Fed) and aluminum (Ald) oxides. The content of organic matter decreased with soil depth. (2) All these soils were in heavy texture. Aggregate tensile strength generally decreased with the increase of aggregate size. For the same size aggregates

tensile strength showed a decreased trend from north to south in China. (3) Tensile strength was correlated positively with pH

silt content and vermiculite content significantly (R>0.63

p<0.01)

while negatively with clay content

1.4 nm transition mineral content

kaolinite content

Fed and Ald (R