Biochar granulation enhances plant performance and leachate water quality on a green roof substrate

Biochar has been promoted as an ideal substrate additive on green roofs. However, biochar is susceptible to wind and water erosion. Applications of granulated biochars or large biochar particles may increase biochar erosion resistance, but the effects on plant performance and leachate quality have not been examined. Therefore, we investigated the effects of two types of biochars at a wide particle size range on plant performance and leachate quality. We found that granulated biochars enhanced plant performance and integrated water quality and reduced leachate total suspended solids (TSS). In contrast, unprocessed biochars suppressed plant performance and increased the leachate TSS.