The Effect of Biochar Addition on Infiltration Rate and Soil Aggregation in the Lab

Abstract

The continuation of biweekly wetting-drying cycles to twelve soil types from four states allowed for the effect of biochar-amendment to be more clearly observed. The hypothesis that biochar amendment would increase infiltration in most soils depending on soil mineralogy and texture was tested. Of the twelve soils tested, six showed biochar-amended soils having higher steady state percolation rates compared to soils without biochar, as seen in Figure 4.1. These soils include DE-1, DE-3, MD-1, MD-2, MD-3, and NC-2. These increases in infiltration will be beneficial to stormwater treatment. Biochar has proven to reduce soil swelling for all replicates compared to control soils. Soils with biochar also show lower area of surface cracks before each storm event compared to control soils. The relation between the effective hydraulic conductivity ratio of soils with biochar to soils without biochar and volume change in control soils was also identified. Biochar amendment is beneficial in reducing soil swelling and cracking for replicates.