Submitted to: Transactions of the ASAE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/4/1996
Publication Date: N/A
Interpretive Summary: Runoff from fields fertilized with poultry litter can have high concentrations of heavy metals, such as copper, iron and zinc. Vegetative filter strips (VFS) have been shown to significantly reduce nutrient runoff from poultry litter, but the effect on metal runoff in unknown. A runoff study was conducted using tall fescue plots and rainfall simulators to find dout the effect of VFS on metal runoff. Vegetative filter strips had a significant effect on metal runoff, with concentrations typically decreasing in a dramatic fashion. Significant reductions occurred mainly in the first 3 meters (about 10 feet).
Technical Abstract: Runoff from land areas amended with poultry (Gallus gallus domesticus) manure can contain elevated concentrations of metals such as Cu, Fe, and Zn. Vegetative filter strips (VFS) can reduce runoff concentrations of animal manure components, but reported studies have typically focused on nutrients and solids rather than metals. This experiment assessed the impact of VFS length (0 to 12 m) on concentrations and mass losses of Cu, Fe, K, Na, Ni, and Zn in runoff from fescue grass (Festuca arundinacea Schreb.) Plots (1.5 m wide x 6 and 12 m long) treated with poultry litter. The runoff was produced from simulated rainfall applied at 50 mm h**-1 until 1 h of runoff had occurred. Runoff Ni concentrations were below detections levels in all cases. Concentrations of Cu, Fe, K, Na, and Zn did not differ between litter-treated plot lengths but were significantly (p<0.001) affected by VFS length, decreasing in an approximately first-order fashion. Means separation indicated that concentrations of Cu Fe, K, and Zn did not significantly decrease after a VFS length of 3 m, while Na concentrations decreased up to a VFS length of 6 m. Mass transport of only Cu significantly decreased with increasing VFS, suggesting that VFS removal mechanisms such as adsorption to clay particles might play a larger role with regard to Cu than to Fe, K, Na, and Zn.