Project Number: 6209-31630-002-21
Project Type: Reimbursable

Start Date: Sep 01, 2006
End Date: Feb 28, 2009

Objective:
To determine, in cooperation with scientists from Texas AgriLife Research and Extension Center (formerly TAES) , WTAMU, and TAMU, atmospheric ammonia and methane concentrations and emissions at commercial beef cattle feedyards. Additionally, to determine the effects of environmental and management factors on ammonia and methane concentrations and emissions.

Approach:
Ammonia and methane emissions from two commercial beef cattle feedyards in Texas with differing management and nutritional regimens will be measured continuously for approximately one year using open path lasers and a backward Lagrangian stochastic model. Effects of environmental conditions on ammonia and methane emissions will be determined. Nitrogen balance will be determined at the same feedyards based on chemical composition of rations, fresh feces, aged manure, and compost in order to support or refute the validity of the ammonia emissions obtained. These data can potentially serve as important components of computer models to predict ammonia and methane emissions from feedyards and to estimate the quantity and quality of manure removed from the feedyard. To study potential methods to decrease ammonia emissions from feedlot pen surfaces, a static chamber will be used in short intervals to measure the effects of pen surface treatments (urease inhibitors, alum, fat, zeolite, etc.) and environmental factors on ammonia emissions from urine spots. Ammonia emissions will be compared and correlated to chemical changes on the pen surface.