Effects of Compost Incorporation on Nutrient Availability and Vegetation Establishment on Construction Sites

Presentation Description : This presentation will be on the role of compost incorporation in post-development urban landscape restoration for improving nutrient availability, vegetation establishments, stormwater infiltration, and soil stabilization. Participants will learn the effectiveness of wildflowers as erosion control vegetation establishment in varying slopes.

Full Presentation Abstract: Urban soils are highly degraded and prone to erosion, and lack of nutrients poses challenges for establishing resilient vegetation cover. This 24-month study investigated the potential of compost incorporation for enhancing soil nutrient availability and erosion-control vegetation establishment along with use of wildflower as an alternative to conventional grass practices in urban landscapes. A split plot design was used where three vegetation (grass, grass-wildflower, and wildflower) as main plot and four amendment treatments, namely compost-fertilizer (CF), compost-no fertilizer (CNF), no compost-fertilizer (NCF), and no compost-no fertilizer (NCNF) as the subplot factors were evaluated. Significant improvements in soil chemical properties (pH, CEC, humic matter) and macronutrient availability (P, K, Ca, Mg, and S) were found with compost incorporation even after 24 months. Additionally, compost positively influenced Mn and Zn availability while decreasing copper availability by 17-30 %. Compost incorporation increased organic carbon 2.5 times, total nitrogen 2 times, and reduced the C/N ratio to ~10, indicating sustained nitrogen mineralization and carbon sequestration potential over an extended period. CF, CNF, and NCF treatments resulted in significantly higher vegetation cover up to 13 months compared to NCNF, reaching about 95-98 % coverage. Except during the first winter, the three vegetation types had similar total vegetation cover, suggesting that integrating wildflowers into urban landscapes for erosion control is viable. Volunteer plant cover was higher in unamended plots, suggesting that compost incorporation does not necessarily promote volunteer plant infestation. This study underscores the potential of compost incorporation as a sustainable urban soil management practice, especially for soil quality improvement and vegetation cover establishment.