Vegetation and soil quality effects from hydroseed and compost blankets used for erosion control in construction activities

ABSTRACT:

Soil erosion is one of the biggest contributors to nonpoint source pollution in the United States. Soil loss rates from construction sites are 10 to 20 times that of agricultural lands. The use of surface applied organic amendments has been shown to reduce runoff and erosion through enhanced vegetation growth and soil quality characteristics. The objective of this study was to evaluate the vegetation growth and soil quality effects from compost blanket and hydroseed applications to soils disturbed by construction activities. Four types of compost blankets, two hydroseeded treatments (silt fence and mulch filter berm) and a bare soil (control) were applied in field test plots. Treatments were seeded with common Bermuda grass (Cynodon dactylon). Vegetative growth (percent cover and biomass of weeds and grasses) and soil quality characteristics were evaluated periodically over one year and 18 months, respectively. Results showed compost blankets provided an average of 2.75 times more vegetative cover than hydroseed after three months. After one year, cover was similar, but hydroseed had significantly greater weed biomass than compost and a greater ratio of weed biomass relative to Bermuda grass biomass. One type of compost blanket increased surface soil extractable organic carbon, and another type increased organic matter in 0 to15 cm (0 to 6 in) soil depths relative to hydroseed treated soils. A one-time application of hydroseed that included mineral phosphorus (P) fertilizer elevated surface soil P after 18 months. On construction sites where disturbed soils are prone to erosion and vegetation establishment is required, compost applications will promote quicker vegetation cover with less weed growth than hydroseeding. Some compost erosion control blankets have the ability to increase soil quality characteristics relative to hydroseed applications within 18 months of application.