Fig. 4 Variation in soil bulk density changes at different depths with different rates of sludge application following a wetting event in (A) silty clay soil, (B) loamy soil, and (C) sandy loam soil. Each value in this figure represents the mean of the changes in bulk density for each application rate (i.e., the average of the values from the three replicates). SE = standard error. The , *, ** symbols represent the linear contrasts significant at P 0.10, 0.05, and 0.01, respectively