Impact of clay on wind erosion for a dry and loose soil surface
We did not measure soil loss for the dry mixed soil in the absence of a
soil crust because we hypothesized that clay amendment impacts wind
erosion within limits for a dry and loose soil surface. This can be
verified by wind erosion models. We used the Revised Wind Erosion
Equation (RWEQ) model to quantify the impact of clay amendment for a dry
and loose soil surface. RWEQ estimates soil loss influenced by clay
content in terms of soil erodible factor (EF ):
QR =EF*Qs (2)
\(\text{EF}=\frac{29.09+0.31sa+0.17si+\frac{0.33sa}{\text{cl}}-2.59OM-0.95CaCO}{100}\)(3)
where sa, si, cl, OM , and CaCO are respectively the
percentage of sand, silt, clay, organic material andCaCO3 in the soil,\(\frac{\text{sa}}{\text{cl}}\) is the sand to clay ratio (range =1.2 to
53) (Fryrear et al., 1998). Where QR is the soil
loss in the presence of clay amendments, whereasQS is the soil loss for the original soil. Soil
losses simulated by RWEQ as a function of clay amendment for the four
soil types are shown in the Figure 4. However, regression analysis
between clay amendment and soil loss indicated that both clay amendment
and soil loss are not statistically related (p<0.1). Simulated
soil loss decreased with the increasing clay amendment. RWEQ simulated
soil loss was reduced by 36%, 37%, 47% and 71% for Athena, Walla
Walla, Warden, and Farrell soil in the presence of 16% clay amendment.
Nonetheless, the rate of change in wind erosion was far less than those
caused by clay amendment within the disturbed crust surface through
crust and aggregate properties (discussed in section 3.4 and 3.5). The
results indicated clay amendment impacts wind erosion within limits for
the dry and loose soil surface.