Improving green infrastructure: Enhancing multidimensional benefits from a soil health perspective.

Abstract

Green infrastructure offers an effective solution to the challenges of runoff control, pollutant removal, and carbon storage in urban water management, but few studies have focused on optimizing the structure and effectiveness of the facilities themselves. This study evaluated the effects of five practical improvement measures, including the addition of herbaceous biochar (HB), wood biochar (WB), earthworm activity (EA), chemical fertilizer (CF) and leaf litter (LA), on green infrastructure in terms of carbon sequestration, pollution reduction, and, ultimately, soil health. The results showed that runoff control was more than 70 % in all groups, and the pollutant removal rates were total phosphorus (81.6 %-93.3 %), ammonia nitrogen (69.9 %-79.2 %), and chemical oxygen demand (42.0 %-61.9 %), respectively. Biochar significantly increased soil organic carbon (SOC) stock, with SOC stock reaching 52.5 Mg C/ha in HB and 25.0 Mg C/ha in WB. In terms of soil health, WB showed the highest soil quality index (2.57), an improvement of 25 % compared to the control group. The individual application of EA and LA showed limited effects. Overall, this study provides an important scientific basis for the optimal design and management of green infrastructure.