Submitted to: Transactions of the ASAE
Publication Type: Peer reviewed journal
Publication Acceptance Date: 2/2/1998
Publication Date: N/A
Citation: Interpretive Summary: Problems can arise when horse manure and sewage sludge is land applied, due to surface runoff of pollutants like phosphorus. The objective of this study was to determine the effect of adding aluminum sulfate (alum) to horse manure and sewage sludge on the amount of runoff of nutrients and harmful bacteria from small plots. Devices that create artificial rainfall were used to provide enough water to cause surface runoff. Runoff water samples were analyzed for nitrogen, phosphate, harmful bacteria, and hormones that occur in animal manures. Alum decreased phosphorus runoff, as expected, but increased nitrate ruoff. Other parameters were not affected. These studies contribute to our understanding of how alum interacts with animal manures to make these manures more friendly to the environment when they are applied to land surfaces.
Technical Abstract: Land application of horse stall bedding and municipal sludge can increase runoff concentrations of nutrients, organic matter and bacteria as well as steroidal hormones such as estrogen. Aluminum sulfate (alum) has the potential for reducing concentrations of materials in runoff from sites treated with animal manures. The objectives of this study were to (a) quantify concentrations of nitrate, ammonia, ortho-phosphorus, fecal coliform, chemical oxygen demand and 17-beta estradiol in runoff from plots treated with horse stall bedding and municipal sludge; (b) assess runoff quality effects of alum addition to those treatments; and (c) determine time variations in concentrations of the analysis parameters. Horse bedding and municipal sludge were applied to twelve 2.4 by 6.1 m fescue plots. Three of the bedding-treated and three of the sludge-treated plots were treated with alum. Simulated rainfall (64 mm/h) was applied to the 12 treated plots and to three control (no treatment) plots. Mass losses of all parameters were low and agronomically insignificant. Alum addition decreased runoff PO4-P concentrations and increased NO3-N concentrations but had no effect on concentrations of other parameters.