The impact of a wood biochar on stormwater retention and infiltration in roadside soils seeded with turfgrass
Date
2023
Authors
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Publisher
University of Delaware
Abstract
Greenway soils that are directly adjacent to the roadside are typically highly compacted and degraded from construction. These soils are no longer "natural," and have altered physical properties that decrease stormwater infiltration, volume of water retained, and water quality with a negative impact on vegetation establishment and growth. One way to mitigate this loss in soil function is to amend existing roadside soils with biochar, which may enhance soil structure, resulting in improved stormwater infiltration and retention. A comprehensive laboratory study was conducted to examine the influence of biochar amendment on the early-time (one-year) performance of a typical roadside soil. The impact of biochar amendment, turfgrass amendment, and compaction on runoff reduction (RR), water retention, water-stable aggregation (WSA), and soil structure were examined. RR and water retention increased with increasing biochar content and the presence of turfgrass, and these effects were most pronounced in highly compacted soils. Independently developed models to predict the effect of biochar on soil hydrology and water retention were consistent with measurements of RR and water retention. While there was minimal statistical difference in WSA between all treatments, differences in soil structure with biochar amendment and turfgrass were observed in x-ray images, particularly in the compacted soils. These results show that amending soils with a wood biochar could be a viable, sustainable solution for enhancing stormwater treatment through increased infiltration and retention through improved soil physical properties.
Description
Keywords
Water-stable aggregation, Biochar, Runoff reduction, Hydrology, Soil structure, Turfgrass