Sediment and Phosphorus Losses From Newly Planted Cool-Season Turfgrass Areas.

Sediment and nutrient losses [e.g. phosphorus (P)], from runoff to surface water, can contribute to eutrophication of lakes and streams. Many home lawns are established on low-P sub-soil which may result in slow seedling development and further exacerbate sediment loss.  Quantifying the potential sediment and P losses from several common cool-season turfgrass establishment methods is important in minimizing the runoff impact from home lawns on surface water bodies.  Two independent simulated rainfall events were conducted 14 and 42 days after planting (DAP) on a calcareous clay-loam sub-soil with a slope of 3.5% to evaluate the effect of various establishment methods.  These methods included Kentucky bluegrass (Poa pratensis L.) sod, tall fescue (TF) [Schedonorus phoenix (Scop.) Holub.] seed, TF + a straw erosion control blanket, TF + compost and TF + sod buffer strips with P rates of 0, 32 and 86 kg P ha^-1 applied using a natural organic (5-4-5) and synthetic product (treble super phosphate).  Turfgrass canopy cover during the rainfall events ranged from 6-100% which influenced runoff and sediment losses. Time to continuous runoff, sediment loss, runoff, soluble phosphorus (SP) and total phosphorus (TP) all declined from the first simulation14 DAP to 42 DAP as turf cover increased.  Bare soil resulted in the highest cumulative mean sediment loss of 339 and 91 g m^-2 14 and 42 DAP, respectively and sediment losses of 14 and 11 g m^-2, from sod 14 and 42 DAP, respectively.  All treatments resulted in 57 to 81% reduction in total cumulative runoff loss compared to the bare soil control 14 DAP. Sod, buffer strips and straw blankets were highly effective in reducing sediment (14-57 g m^-2) losses compared to seeded treatments (88 g m^-2) and bare soil (339 g m^-2) 14 DAP.