Air pollution
; Digital storage
; Economics
; Environmental impact
; Ethanol
; Gas chromatography
; Methanol
; Organic compounds
; Ozone
; Particulate emissions
; Uncertainty analysis
; Volatile organic compounds
; Dairy farms
; Management options
; Process-based modeling
; Reducing emissions
; Silage
; System modeling
; Transport coefficient
; Uncertainty in measurement
; Farms
; alcohol
; methanol
; volatile organic compound
; agricultural emission
; alcohol
; atmospheric modeling
; cattle
; chemical pollutant
; dairy farming
; economic activity
; emission control
; environmental impact
; farming system
; ozone
; pollutant source
; silage
; troposphere
; volatile organic compound
; agricultural land
; Article
; California
; dairying
; environmental economics
; environmental impact
; exhaust gas
; food storage
; maize
; prediction
; predictive value
; priority journal
; process model
; silage
; simulation
; California
; United States
; Zea mays
Scopus学科分类:
Environmental Science: Water Science and Technology
; Earth and Planetary Sciences: Earth-Surface Processes
; Environmental Science: Environmental Chemistry
英文摘要:
Silage on dairy farms can emit large amounts of volatile organic compounds (VOCs), a precursor in the formation of tropospheric ozone. Because of the challenges associated with direct measurements, process-based modeling is another approach for estimating emissions of air pollutants from sources such as those from dairy farms. A process-based model for predicting VOC emissions from silage was developed and incorporated into the Integrated Farm System Model (IFSM, v. 4.3), a whole-farm simulation of crop, dairy, and beef production systems. The performance of the IFSM silage VOC emission model was evaluated using ethanol and methanol emissions measured from conventional silage piles (CSP), silage bags (SB), total mixed rations (TMR), and loose corn silage (LCS) at a commercial dairy farm in central California. With transport coefficients for ethanol refined using experimental data from our previous studies, the model performed well in simulating ethanol emission from CSP, TMR, and LCS; its lower performance for SB could be attributed to possible changes in face conditions of SB after silage removal that are not represented in the current model. For methanol emission, lack of experimental data for refinement likely caused the underprediction for CSP and SB whereas the overprediction observed for TMR can be explained as uncertainty in measurements. Despite these limitations, the model is a valuable tool for comparing silage management options and evaluating their relative effects on the overall performance, economics, and environmental impacts of farm production. As a component of IFSM, the silage VOC emission model was used to simulate a representative dairy farm in central California. The simulation showed most silage VOC emissions were from feed lying in feed lanes and not from the exposed face of silage storages. This suggests that mitigation efforts, particularly in areas prone to ozone non-attainment status, should focus on reducing emissions during feeding. For the simulated dairy farm, a reduction of around 30% was found if cows were housed and fed in a barn rather than in an open lot, and 23% if feeds were delivered as four feedings per day rather than as one. Reducing the exposed face of storage can also be useful. Simulated use of silage bags resulted in 90% and 18% reductions in emissions from the storage face and whole farm, respectively. � 2016
Pasture Systems and Watershed Management Research Unit, USDA Agricultural Research Service, University Park, PA, United States; Department of Chemical Engineering, Biotechnology and Environmental Technology, University of Southern Denmark, Odense, Denmark; Plant Science Department, The Pennsylvania State University, University Park, PA, United States; Department of Animal Science, University of California, Davis, CA, United States
Recommended Citation:
Bonifacio H,F,, Rotz C,et al. A process-based emission model of volatile organic compounds from silage sources on farms[J]. Atmospheric Environment,2017-01-01,152