Assessing the influence of primary soil particles on soil aggregate
distribution for different breakdown mechanisms: A new method
- Hai Xiao,
- Mingyi Li,
- Yueshu Yang,
- Feng Gao,
- Zhenyao Xia,
- Lun Zhang,
- Ping Guo,
- Wennian Xu
Abstract
Soil aggregates are the basic unit structing soils, and their stability
is an important index for soil degradation. However, current
methodologies rarely assess the influence of primary soil particles on
soil aggregates distribution for different breakdown mechanisms.
Therefore, a new method that separates the primary soil particles from
the soil aggregates for different breakdown mechanisms with a series of
in-lab experiments were developed to fill this gap. The whole soil
sample was treated by fast wetting, slow wetting, and mechanical
breakdown by pre-wetting and stirring to simulate the different
breakdown mechanisms of slaking, differential swelling of clays, and
mechanical breakdown by raindrop impact, respectively. Then, attempts
were made to separate the primary soil particles from the soil
aggregates of various particle size fractions by using sodium
hexametaphosphate and hydrogen peroxide to eliminate the influence of
the primary soil particles on the soil aggregate distribution. Four
soils collected from different areas with different soil textures were
used to assess the soil aggregate distribution by using the new method
to highlight the importance of separating the primary soil particles
from the soil aggregate for different breakdown mechanisms. The results
indicated that the primary soil particles have much greater influence on
the micro-aggregates than on macro-aggregates. Different breakdown
mechanisms and soil types could affect the influence of the primary soil
particles affects the on soil aggregate distribution. This study
highlights the influence of separate primary soil particles on soil
aggregate distribution for different breakdown mechanisms.