Submitted to: American Society of Agricultural Engineers Meetings Papers
Publication Type: Abstract Only
Publication Acceptance Date: 10/11/2000
Publication Date: N/A
Technical Abstract: Dispersion characteristics around manure storage units determine the rate at which malodorous compounds move from the source into the surrounding atmosphere. There is little information on the air flow patterns and the microclimate around manure storage units that can be used to assess these dispersion characteristics. We designed a study that was conducted around and within lagoons in Iowa and Arkansas. The instrumentation was similar between the two sites, and measurements were made for almost 14 months from April 1997 through September 1998. Air temperature, relative humidity, and windspeed at 1 m above the berm were measured on each side of the lagoon. An additional unit was placed in the center of the lagoon on a buoy and held in position with a cable that extended across the lagoon. These instruments were recorded as 30 minute values throughout the study. To measure the turbulent exchanges around a lagoon we placed a three-dimensional sonic anemometer on the south and north berm and two on the lagoon surface, one near the south berm and one in the center. These units recorded data at 10 hz for a week to quantify the turbulent exchanges. Placement of manure storage units with the surrounding vegetation increases the air exchanges across the lagoon surface. Manure storage units are subjected to rapid dispersion that leads to enhanced transport into the atmosphere. There are large variations in these dispersion efficiencies throughout the year that are induced by changes in the elevation of the liquid surface and the characteristics of the surrounding vegetation. Increasing our understanding of air flow and dispersion around manure storage units will help us develop landscape practices to reduce offsite movement.