Pasture runoff can contribute to elevated concentrations of nutrients, solids, and bacteria indownstream waters. The objective of this study was to determine the effects of vegetative filter strip(VFS) length on concentrations and transport of nitrogen, phosphorus, solids and fecal coliform inrunoff from plots treated with cattle manure. Three plots with dimensions of 2.4× 30.5 m wereused. The upper 12.2 m of each plot was treated with cattle manure, while the lower 18.3 m acted asa VFS. Runoff produced by rainfall simulators was sampled at VFS lengths of 0, 6.1, 12.2, and 18.3m and analyzed for total Kjeldahl nitrogen (N), ammonia N, nitrate N, total phosphorus (P), ortho-P, fecal coliforms, total suspended solids and other parameters. The VFS significantly reducedconcentrations and mass transport of incoming solids, fecal coliform, and most nutrient forms,particularly P The relationships among VFS length, concentration and mass transport were well-represented by first-order exponential decay functions. Approximately 75 of incoming totalKjeldahl N, total P ortho-P and total suspended solids was removed within the first 6.1 m of the filterstrips. Runoff concentrations of fecal coliform concentrations entering the filter strips were as high as2× l0{sup}7 FC/100 mL; after a filter length of 6. m, however, the runoff exhibited no measurableconcentration of fecal coliforms. This experiment suggests that even relatively short filter strips canmarkedly improve quality of runoff from grassed areas receiving cattle manure.
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