Evaluation of Soil Erosion and Soil Erodibility Factors for Composted Organics on Highway Right-of-Ways

Runoff and interrill erosion were measured on three composted organics applied at 5-cm and 10-cm depths, a topsoil treatment (15-cm application), and the existing soil on a highway embankment with a 3 to 1 slope. Treatments were tested immediately after preparation and six weeks later to allow for the vegetative cover crop to grow. Rainfall simulations were conducted at an average intensity of 95 mm/hr. The depth of compost application was a significant factor for runoff rates and infiltration rates of the un-vegetated plots. Compost application depth was not an important factor in measured interrill erosion rates or calculated interrill erodibility factors for un-vegetated plots. The depth of compost application was not a significant factor on the vegetated plots. Vegetated compost treatments were effective at reducing runoff rates and interrill erosion rates compared to the topsoil and control treatments. Compost treatments had significantly lower interrill erosion rates and interrill erodibility factors compared to topsoil and control treatments on un-vegetated plots.