Evaluation of Various Establishment Techniques Implemented to Reduce Sediment and Runoff Loss.

Sediment and nutrient runoff, especially phosphorus (P), from losses from lawns to fresh surface waters, contributes to accelerated eutrophication of lakes and streams, a process whereby increased aquatic plant causes a reduction of water clarity, habitat loss, and decreased dissolved oxygen levels which can lead to taste/odor problems and widespread fish kills.  Although Indiana soils generally contain adequate (>13 mg P kg^-1) P, many new lawns are established on low-P subsoil which may result in slow seedling development and further exacerbate sediment loss. Two independent field-scale simulated rainfall (approx. 40 mm hr^-1) events were conducted 14 and 43 days after planting on a calcareous clay loam subsoil with a 3.5% slope to evaluate the effect of a variety of establishment techniques which included Kentucky bluegrass sod, turf-type tall fescue seed, seed + an erosion control fabric and seed + sod buffer strips with and without supplemental fertilizer. Canopy coverage during the rainfall events ranged from 6-100% turf cover which strongly influenced the time to continuous runoff and sediment loss. Sediment loss from the bare soil control was 2360 and 633 kg ha^-1 for event 1 and 2 respectively. The most effective treatments for reducing sediment loss were sod, seed + a sod buffer strip, seed + erosion blanket and fertilization at seeding which produced turf coverage ranging from 23-30 % in the non-sodded plots. Where reduced sediment loss is desired during seedling establishment it is recommended that seedlings be supplementally fertilized early in the developmental phase and sod or sod buffer strips be installed adjacent to hardscape.