5% biochar-amended soil presented unobvious changes throughout the duration, and a gradual decrease in porosity appeared in the 5% biochar-amended soil. Fig. 2g indicates that MWD of soil aggregation PS-341 cost was consistently higher for the biochar-amended soils than the control after incubation of 21 d; however, significant differences between the amended soils and the control were found after incubation of 84 d. An obvious peak that occurred at 21 d was found

for all treated soils. Furthermore, applying biochar to the soil caused a significant increase in the saturated hydraulic conductivity (Ksat). At the end of the incubation, the Ksat values of the amended soils were twice as high as the control soils (Table 2), although there were great variances found at the beginning of the incubation, especially for

the 5% biochar amended buy SB431542 soil (Fig. 2h). After incubation of 21 d, the Ksat stabilized gradually and kept higher consistently for the biochar-amended soils to the end of the incubation. To understand the changes of soil microbial activity after biochar application, the microbial biomass carbon (MBC) contents were determined at 0 d, 21 d, 63 d, and 105 d of incubation. Results indicate that the biochar application significantly increased the MBC at the beginning of incubation, 63 d and 105 d (only in 5% application rate). The differences were statistically significant (p < 0.05), except for the analytical results at 21 d ( Fig. 3). In addition, the highest contents of MBC were found at 21 d for each treated soil, which were 3200 mg kg− 1 for 5% biochar-amended

soil, 1145 mg kg− 1 for 2.5% biochar-amended soil and 1759 mg kg− 1 for the control, respectively. Table 2 shows the soil loss rate under a simulated rainfall intensity of 80 mm h− 1. The highest soil loss rate (1458 ± 50.0 g m− 2) GBA3 occurred in the control soil, and the lowest (532 ± 106 g m− 2) occurred in the amended soil with the highest application rate (5%). The soil loss rate significantly decreased as the biochar application rate increased, indicating that biochar largely ameliorated soil erosion potential in highly weathered soils. The results of this study confirmed the effectiveness of wood biochar in improving the physical and chemical properties of soil that is highly weathered. The results indicated that the improvements in soil characteristics varied with variations in the amount of biochar added to the soil. Incubation results indicated that soil pH, CEC, and BS increased significantly after the addition of biochar, particularly at the application rate of 5%. The high liming potential of the biochar (pH > 9.0) raised the pH of the highly weathered soil. Our results further showed that pH increased significantly with increasing application rates of biochar, reflecting the fact that the liming potential increased with increasing application rates of biochar.