Impact of aggregate GMD on soil loss
Only aggregate GMD and crushing energy appeared to increase with increasing crust crushing energy for the four soil types. The relationship between aggregate GMD and soil loss for the four soil types examined in this study is illustrated in Figure 7b. Soil loss appeared to decrease linearly with increasing aggregate GMD. Actually, soil loss is directly related to the amount of aggregates >0.84 mm in diameter, which are considered nonerodible aggregates (Zobeck et al., 2011). However, the impact of aggregate GMD on soil loss varied among soil types based on regression coefficients and ANOVA. We found that the impact of aggregate GMD on soil loss was higher for Farrell sandy loam and Warden sandy loam than Walla Walla silt loam and Athena silt loam based on the regression coefficients (Figure 7b).
Aggregate size distribution not only determines the amount of wind erosion due to the amount of erodible size aggregates present on the soil surface, but also impacts other key wind erosion factors such as the threshold friction velocity, PM10 or suspension potential (Zobeck,1991b). The impact of aggregate crushing energy on wind erosion will be discussed in section 3.6.