Compost Improves Compacted Urban Soil.

Urban construction sites usually result in compacted soils that limit infiltration and root growth. The purpose of this study was to determine if compost, aeration, and / or prairie grasses can remediate a site setup as a simulated post-construction site (compacted). Five years after establishing the control (5 cm topsoil + bluegrass mixture) and treated areas (5 cm topsoil + 10 cm compost + prairie grasses), a rainfall simulation study was conducted. The areas with prairie grass had greater infiltration rates (2.5"/hr) compared with the control (2.1"/hr), and less sediment loss (22 vs 106  lb/Ac-h). Ortho phosphate loss was less for the prairie grass ( 0.05 lb/Ac) than for the bluegrass area (0.36 lb/Ac). Sampling to 2 m depth revealed prior disturbance to > 0.5 m for the whole area. Compost is recommended for post construction sites. Over time, prairie grasses were also beneficial. Soils in urban areas can have several disturbance events.