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United States Department of Agriculture

Agricultural Research Service

Research Project: EMISSION AND DISPERSION OF AIR QUALITY CONSTITUENTS FROM AGRICULTURAL SYSTEMS
2009 Annual Report


1a.Objectives (from AD-416)
Evaluate emission and dispersion patterns to the boundary layer as a function of complex terrain and structural obstructions; Quantify the effectiveness of agricultural management to reduce ammonia and nitrous oxide emissions into the atmosphere; Identify and quantify volatile organic compounds (VOC) attached to particulates emitted from animal feeding operations and manure application on to fields. Identify and quantify amounts of endotoxins and pathogens emitted and dispersed from animal feeding operations and manure application sites.


1b.Approach (from AD-416)
Utilize a wind tunnel to conduct a series of wind flow simulations over model scale terrain and structures to determine the wind flow patterns over complex agricultural sites that include buildings. Conduct lidar measurements of particulates and water vapor coupled with turbulence measurements obtained from sonic anemometers to characterize the turbulence regime in limited fetch environments. Evaluate the potential of using open path FTIR measurements to compliment the lidar measurements in the development of improved emission and dispersion models. Conduct studies on ammonia and nitrous oxide emission from controlled laboratory studies using soil columns and various manure application practices coupled with field studies to ascertain the impact of different soil and cropping management practices on these emissions. Collect particulate samples using samplers located at various positions from different livestock production facilities to determine the variation of particulate concentration and the VOC compounds attached to the particulates.


3.Progress Report
Through the use of Lidar and turbulence measurements in the vicinity of a poultry facility, the first estimates of particulate flux emissions are now being computed. This is critical to accurately evaluate management strategies to reduce emissions of particulates and gases to the atmosphere. Preliminary results clearly show that particulate emissions are not emitted as a Gaussian plume. This has serious implications for modeling efforts that assume Gaussian plume distribution. Additionally, turbulent transport processes are shown to be affected by building structures and windbreaks in a manner that cannot be described by simple assumptions. Alternative conservation tillage practices are shown to significantly reduce particulate emissions when compared with conventional methods. As part of our joint efforts with the Space Dynamics Laboratory (SDL), Environmental Protection Agency (EPA), and San Joaquin Air Resources Board, a study was completed that involved monitoring a dairy for particulate and ammonia emissions. Final report is in progress, but initial results indicate ammonia concentrations of 25-500 ppbv downwind from the dairy. This is result of a collaborative effort with the EPA and the San Joaquin Air Resources Board. Processing Lidar and turbulence data from swine and poultry buildings has resulted in two-dimensional maps of particulate emissions that reveal for the first time how complex emission and transport of particulates actually are. This is in sharp contrast to current model representations of emission and transport from animal facilities which assume a simplified Gaussian dispersion. Additionally, the two-D maps show vertical heights of emissions easily in excess of 50 m above the surface during the daytime. Current processing of the Lidar and meteorological data are yielding measured particulate flux estimates at the whole facility scale for the poultry facility. With respect to swine facility monitoring, sample collection and analysis for endotoxins were completed. Sample collection and analysis were reassigned to other units thus completing the work in this area. A significant collection of articles discussing particulate emissions and specifically their composition is current. New publications will be collected as they are generated. Objective 3 has been completed and no further research is anticipated.


4.Accomplishments
1. Simulating Atmospheric Stability Conditions in a Wind Tunnel Control Section. The control section of the National Soil Tilth Laboratory (NSTL) low-speed wind tunnel was modified to simulate stable (surface cooler than air above) and unstable (surface warmer than air above) atmospheric conditions. Tubing was arranged beneath the floor of the control section through which fluid was circulated from a heat exchanger. This system allowed both cooling and warming of the control section floor. A rake with 19 thermocouples from 2 to 455 mm above the control section floor was deployed to measure air temperature profiles. By balancing the fluid temperature and flow rate, equilibrium conditions could be reached within ~ three hours for varying stability conditions and air flow. The modified wind tunnel can now accurately simulate typical seasonal and diurnal variations in atmospheric conditions.

2. Lidar and Turbulence Measurements in the Flow Domain of a Poultry and Swine Facility. A particulate emission study was conducted at a poultry facility in north-central Iowa. This study focused on the effect of buildings and a windbreak on the transport of particulates emitted from poultry and swine buildings. Additional measurements on the emission of ammonia from these buildings were also made and found to be well correlated with the transport of particulates. Two important accomplishments were the determination that the flow field in the vicinity of buildings and windbreaks was significantly different than the traditional assumed Gaussian distribution. This was supported by the two-dimensional maps generated by the Lidar. Additionally, the first particulate emission fluxes were computed at a facility scale using Lidar and micrometeorological measurements. This was accomplished for both swine and poultry buildings. Emission totals from swine and poultry units are being evaluated. The impact of these accomplishments is the discovery of complex turbulence production zones that result in the vertical lofting of particulates at rates and heights not predicted by gaussian plume models. This will lead to modification of existing models to account for these turbulent zones.

3. Comparison of conventional and conservation tillage practices and its effect on particulate emissions. Particulate emissions in the San Joaquin Valley are significantly increased as a result of multiple passes made during each cultivation cycle. Typical stable boundary-layer conditions (inversions) can trap much of the particulates near the surface significantly impacting air quality. A study was conducted to evaluate particulate emissions from two different tillage systems following the harvest of wheat prior to the planting of corn in the lower San Joaquin Valley of California. This study is a result of an agreement involving United States Department of Agriculture (USDA) Agricultural Research Service (ARS), Environmental Protection Agency (EPA), the San Joaquin Air Pollution Control District, and the Space Dynamics Laboratory in support of project 3625-11630-002-00D, (Emission and Dispersion of Air Quality Constituents from Agricultural Systems). The tillage systems compared were the typical sequential operations with individual tillage implements compared to a single-pass planting operation that planted the corn directly into the wheat residue. Complete fields were evaluated and the study design was developed to measure particulate concentrations at the upwind and downwind positions along each side of the field. These measurements were coupled with micrometeorological measurements to determine atmospheric turbulence and stability. All of these observations are being combined to estimate a particulate flux for the different tillage operations. Preliminary results showed the single pass system reduced the particulate matter (PM) emissions but there was little effect on the PM2.5 emissions because these emissions were not affected by tillage operations.

4. Field assessment of Nitrous Oxide (N2O) flux from manure applied to soil. Summarized results from a study investigating: i) the temporal patterns of N2O emissions following addition of swine manure slurry in a laboratory setting under fluctuating soil moisture regimes, ii) assessed the potential of a rye (Secale cereale L.) cover crop to decrease N2O emissions under these conditions, and iii) quantified field N2O emissions in response to either spring applied urea ammonium nitrate (UAN) or different rates of fall-applied liquid swine manure, in the presence or absence of a rye/oat winter cover crop. In laboratory experiments we observed a significant reduction in N2O emissions in the presence of the rye cover crop. Field experiments were performed on a fine-loamy soil in Central Iowa from October 12, 2005, to October 2, 2006. Nitrous oxide emissions were evaluated at three swine manure application rates and with spring applied UAN, in the presence or absence of an oat/rye cover crop. We observed no significant effect of the cover crop on cumulative N2O emissions in the field. The primary factor influencing N2O emission was nitrogen (N) application rate, regardless of form or timing. The response of N2O emission to N additions was non-linear, with progressively more N2O emitted with increasing N application. These results indicate that while cover crops have the potential to reduce N2O emissions, N application rate may be the overriding factor. A paper was prepared and published.


Review Publications
Jarecki, M.K., Parkin, T.B., Chan, A.K., Hatfield, J.L., Jones, R. 2008. Comparison of DAYCENT-Simulated and Measured Nitrous Oxide Emission from a Corn Field. Journal of Environmental Quality. 37:1685-1690.

Hatfield, J.L. 2008. Special Issue From the 4th USDA Greenhouse Gas Symposium. Journal of Environmental Quality. 37:1311-1318.

Cosh, M.H., Kabela, A., Hornbuckle, B., Gleason, M.L., Jackson, T.J., Prueger, J.H. 2009. Observations of dew amount using in-situ and satellite measurements in an agricultural landscape. Agricultural and Forest Meteorology. 149:1082-1086.

Marchant, C.C., Wilkerson, T.D., Bingham, G.E., Zavyalov, V.V., Anderson, J., Wright, C.B., Cornelsen, S.S., Martin, R.S., Silva, P.J., Hatfield, J.L. 2009. Aglite Lidar: A Portable Elastic Lidar System for Investigating Aerosol and Wind Motions at or Around Agricultural Production Facilities. Journal of Applied Remote Sensing (JARS). 3:033511. [doi:10.1117/1.3097928]

Bingham, G.E., Marchant, C.C., Zavyalov, V.V., Ahlstrom, D.J., Moore, K.D., Jones, D.S., Wilkerson, T.D., Hipps, L.E., Martin, R.S., Hatfield, J.L., Prueger, J.H., Pfeiffer, R.L. 2009. Lidar Based Emissions Measurement at the Whole Facility Scale: Method and Error Analysis. Journal of Applied Remote Sensing (JARS). 3:033510. [doi:10.1117/1.3097919]

Gish, T.J., Prueger, J.H., Kustas, W.P., Daughtry, C.S.T., McKee, L.G., Russ, A.L., Hatfield, J.L. 2009. Soil moisture and metolachlor volatization observations over three years. Journal of Environmental Quality. 38:1785-1795.

Zavyalov, V.V., Marchant, C.C., Bingham, G.E., Wilkerson, T.D., Hatfield, J.L., Martin, R.S., Silva, P.J., Moore, K.D., Swasey, J., Ahlstrom, D.J., Jones, T.L. 2009. Aglite lidar: Calibration and retrievals of well characterized aerosols from agricultural operations using a three-wavelength elastic lidar. Journal of Applied Remote Sensing (JARS). 3:033522. [doi:10.1117/1.3122363]

Last Modified: 8/29/2014
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