The Hydrological Fate Of Nutrients And Pesticides In The Urban Landscape In Response To Management And Lawn Species
The applications of fertilizers and pesticides to home lawns may contribute to the deterioration of ground and surface water quality. Loss of nutrients and pesticides to ground and surface water can be detrimental for human consumption, reduce recreational usage, and negatively impact aquatic organisms. A field study was initiated to examine the effect fertilizer and pesticide applications can have on the concentrations and mass loss of nutrients and pesticides in leachate and runoff. Studies were arranged on a slope of 13-15% of Arkport Sandy Loam soil (coarseloamy, mixed, active, mesic Lamellic Hapludalf) through establishing Kentucky bluegrass (Poa pratensis L.) sod, or mixtures of Kentucky bluegrass sod and traditional weedy species (Taraxacum officinale, Trifolium repens, Plantago major, and Digitaria ischaemum) found in the Northeast of the U.S. Runoff and leachate collected from natural precipitation events were analyzed for nitrate (NO3--N), ammonium (NH4+-N), total Kjeldahl nitrogen (TKN), phosphate (PO43--P), total Kjeldahl phosphorus (TKP), and applied pesticides. Nitrate contributions in leachate reflected the overall largest potential loss from the landscape. Differences were observed among lawn types for NO3--N loss; however significant losses were seen from lawn types regardless of the application of supplemental fertilizer. Ammonium and PO43--P losses in runoff were significantly higher for the fertilized turfgrass plots compared to non-fertilized lawn types. Although differences in nutrient losses occurred from lawn types, less than 2% of total applied N was lost in leachate and less than 1% and 0.5% of N and P applied were lost in runoff respectively. Pesticide applications could pose a risk to water quality, but the risk to off-site surface water contamination appears to be much more prevalent. Over-time, levels of pesticides in runoff were reduced; however during establishment, concentrations of 2,4-D and Mecoprop were greater than 2800 and 1600 [mu]g L-1, respectively, which could negatively impact aquatic organisms. Overall, differences in nutrient loading existed, but the ability of turfgrass to reduce runoff volumes and utilize applied nutrients appeared significant. The percent of nutrients contributed by fertilizer applications to ground and surface water was minimal and may not pose a significant environmental concern.
dissertation or thesis