September 18, 2008
System Offers New Option for Managing Manure ASABE Members Design Alternative System
A typical 1,000-head beef feedlot produces up to 254 metric tons (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 it is far from perfect. Over time, nutrients can percolate through the soil into groundwater. Also, pond maintenance is expensive and difficult.
Research leader and ASABE member John Nienaber worked with agricultural engineers and ASABE members 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.
For more information, contact USDA-ARS public affairs specialist Laura McGinnis, Laura. McGinnis@ ars.usda.gov.
The water on the left was collected in a solids-separation basin at the low end of the feedlot pen (on the right) after a rain. After the solids settle, the water in the basin will be distributed throughout the vegetative treatment area.
Copyright American Society of Agricultural Engineers Jul 2008
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