Residential Lawn Management Impacts on Nutrient and Sediment losses.

Differences in nutrient and sediment movement associated with overland runoff from residential landscapes as a function of management remain poorly defined.   The purpose of this study is to evaluate the loss of nutrients and sediment via overland runoff from three different residential landscapes: a high maintenance fescue (Festuca arundinacea) lawn (HMFL), a low maintenance fescue lawn (LMFL), and a forested residential landscape (RFL) with periwinkle (Vinca minor) understory and leaf litter.  A passive non-intrusive overland runoff catchment system was installed in each residential landscape. Runoff samples generated during natural rainfall events were captured in sterile media collection bags connected to the sampling system.   For each rainfall event, total runoff volumes were recorded and sub-samples analyzed for NO₃^--N, NH₃-N, PO₄^-3-P, and total suspended solids (TSS).  After 8 months of observations, runoff from the HMFL, LMFL, and RFL catchments occurred during 18%, 43% and 14% of the rainfall events, respectively.  The HMFL, LMFL, and RFL lost a total of 2.7 g NH₄⁺-N ha^-1, 19.2 g NH₄⁺-N ha^-1, 3.0 g NH₄⁺-N ha^-1, respectively.  Total NO₃^--N load measured from the LMFL (7.7 g NO₃^--N ha^-1) was higher than the HMFL (3.5 g NO₃^--N ha^-1) and RFL (0.4 g NO₃^--N ha^-1) catchments.  The LMFL catchment lost approximately 78% and 95% more PO₄^-3-P than the HMFL and RFL catchments, respectively.  The TSS total load measured from the LMFL catchment was 80% and 95% higher than the HMFL and RFL catchments, respectively.  Data collected thus far suggest that nutrient and sediment loads are lowest from the RFL system.