水保所知识产出(1956---)知识库

Soil interparticle forces, involving in van der Waals attractive force, and surface hydration and electrostatic
repulsive forces, greatly influence the soil aggregate stability. However, current studies on methods for evalu-
ating the impact of soil interparticle forces in aggregate stability are scarce. This research was aimed to examine
the impact of soil interparticle forces on aggregate stability using diverse methods for different soil types. Soil
aggregate stability was tested through the pipette method, wet sieving, and rainfall simulation, respectively
characterized by aggregate stability index (ASI), mean weight diameter (MWD), and splash erosion mass (SE).
Soil interparticle forces were adjusted by the changing concentrations of NaCl solution. The results showed that
all three approaches can be applied to study the impact of soil interparticle forces on aggregate stability. The ASI,
MWD, and SE showed little change below 10 −2 mol L −1 NaCl concentration and then ASI and MWD increased at
a high rate above 10 −2 mol L −1 concentration of NaCl, while the SE showed the opposite trend. These results
were as expected for soil interparticle forces. Moreover, for a single soil, a substantial correlation existed between
the aggregate stability indicators obtained from three methods. However, the order of soil aggregate stability,
measured by three methods were varied among soil types. Our results suggest that a single method cannot be
applied to determine the aggregate stability of all soil types even if the breakdown mechanism was identical,
because organic matter content and particle size distribution of soil are important factors influencing aggregate
stability. Hence, in order to compare the difference in aggregate stability between various soils, multiple methods
should be considered to investigate the impact of interparticle forces of soil on its aggregate stability. If a single
method was to be chosen, wet sieving may be a good choice as it was not only relatively simple and time-saving
but also reflected more comprehensive information about sizes and amount of fragments released from soil
aggregates.