Author
Bonifacio, Henry | |
Rotz, Clarence - Al | |
Leytem, April | |
Waldrip, Heidi | |
Todd, Richard |
Submitted to: Meeting Proceedings
Publication Type: Abstract Only Publication Acceptance Date: 2/5/2015 Publication Date: 3/31/2015 Citation: Bonifacio, H.F., Rotz, C.A., Leytem, A.B., Waldrip, H., Todd, R.W. 2015. Ammonia and nitrous oxide model for open lot cattle production systems{Abstract}. Waste to Worth. p 72819. Interpretive Summary: Technical Abstract: Air emissions, such as ammonia (NH3) and nitrous oxide (N2O), vary considerably among beef and dairy open lot operations as influenced by the climate and manure pack conditions. Because of the challenges with direct measurements, process-based modeling is a recommended approach for estimating air emissions from animal feeding operations. The Integrated Farm Systems Model (IFSM), a whole-farm simulation model for crop, dairy and beef operations, was previously expanded (version 4.0) to simulate NH3 emissions from open lots. IFSM and performed well in representing emissions for two beef cattle feedyards in Texas. However, the previous model was found to perform poorly in predicting NH3 emissions measured at an open lot dairy in Idaho, so further research was done to better represent the effects of climate on lot and manure pack conditions and to improve models representing nitrification and denitrification processes. The revised model appropriately predicted NH3 emissions for the two Texas beef cattle feedyards, with model predictions having 59 to 79% agreement with measured daily emissions. Simulated NH3 emissions for the Idaho open lot dairy significantly improved with 60% agreement between predicted and measured daily NH3 emissions. For the Idaho open lot dairy, IFSM also predicted daily N2O emissions with 81% agreement to those measured. These results support that IFSM can predict NH3 and N2O emissions from open lots as influenced by climate and lot conditions. IFSM provides a useful tool for estimating open lot emissions of NH3 and N2O. Performance aspects include environmental impact and economics of cattle feeding operations in different climate regions, and evaluating management strategies to mitigate emissions. |