System Offers New Option for Managing Manure

A typical 1,000-head beef feedlot produces up to 280 tons of manure in just one week. That's a lot of manure—and for hundreds of U.S. cattle feedlots, disposal is an important management issue.

Fortunately, Agricultural Research Service (ARS) scientists in the Environmental Management Research Unit at the U.S. Meat Animal Research Center (USMARC) at Clay Center, Neb., have developed and tested a new method of runoff control.

In the United States, feedlot runoff is often stored in a large pond or basin. From there, it is either distributed as nutrient-rich irrigation water or processed for safe disposal. This method is approved by U.S. Environmental Protection Agency, but is far from perfect. Over time, nutrients can percolate through the soil into groundwater. Also, pond maintenance is expensive and difficult.

Research leader John Nienaber worked with agricultural engineers Roger Eigenberg and Bryan Woodbury to design an alternative system, in which runoff containing manure solids enters temporary storage basins at the base of the sloped feedlot.

The basin is large enough to hold runoff for several hours to allow the solid waste to settle to the bottom. The remaining liquid is then drained through distribution tubes that provide even dispersal over a grassy field or "vegetative treatment area" (VTA).

The VTA system, conditionally approved by EPA, has many benefits. It requires minimal management, significantly reduces waste storage time, eliminates the need for costly runoff pumping, and removes standing water.

This manure-disposal technology could also be applied to other livestock. The system should be less expensive to construct and maintain than the traditional system, though the cost and suitability would vary with topography, climate and animal type.

Read more about the research in the November/December 2007 issue of Agricultural Research magazine.