2011 Annual Report
1a.Objectives (from AD-416)
The purpose of this project is to address atmospheric emissions of trace gases from concentrated dairy operations and manure management systems. The goal is to develop emissions factors which will allow decision makers to evaluate the contribution of these constituents from dairy production with other agricultural and industrial sectors and assist in long-term planning efforts aimed at improving air quality and reducing emissions. Additionally, this project examines emissions of bioaerosols from dairy production facilities as well as airborne transport of pathogens during the reuse of dairy wastewater for crop irrigation. This information will be used to determine the potential for off site transport of bioaerosols and pathogens from dairy production, which is a community concern. The specific objectives and goals of the project are listed below (investigator involved and their time commitment).
Objective 1. Determine emission rates of gases and bioaerosols from dairy operations. (Leytem 0.3, Dungan 0.2, Bjorneberg 0.2)
• Research Goal 1.1. Estimate on-farm emissions of ammonia, methane, nitrous oxide, and carbon dioxide from dairy production facilities to determine emission factors that account for diurnal and seasonal fluctuations in emissions.
• Research Goal 1.2. Compare gas monitoring equipment effects on estimates of ammonia and methane emissions.
• Research Goal 1.3. Develop on-farm emissions factors for ammonia, methane, and nitrous oxide from dairy wastewater storage ponds based on wastewater characteristics, management practices, and climatic conditions.
• Research Goal 1.4. Measure airborne concentrations of culturable bacteria, virus, and filamentous fungi and endotoxins downwind from a concentrated dairy operation to assess diurnal and seasonal variations.
Objective 2. Utilize fecal contamination indicators to assess the downwind transport of pathogens in dairy wastewaters delivered via sprinkler irrigation systems. (Dungan 0.3, Leytem 0.2, Bjorneberg 0.1)
• Research Goal 2.1. Assess the transport of aerosolized bacterial and viral pathogens generated during the land application of dairy wastewaters using sprinkler irrigation systems.
1b.Approach (from AD-416)
A year long study will determine the emissions of ammonia, methane, nitrous oxide, and carbon dioxide from the barns and wastewater storage pond of a large freestall dairy. Additionally, bioaerosol transport from the barns to downwind locations will be assessed. The emissions of ammonia, methane, and nitrous oxide from dairy liquid storage ponds will also be assessed in order to determine the factors affecting these emissions and develop better methods for predicting emissions from these systems. An assessment of the transport of pathogens from sprinkler irrigation of dairy wastewater will also be undertaken to determine the risk of pathogen drift to human receptors and potential health risks. A better understanding of the type and amount of constituents released into the air from animal production and manure storage areas are expected results. This information will allow us to develop emissions factors and assess the risk of pathogen drift from these systems.
Significant progress was made on both project objectives that address National Program 214, component 3, Atmospheric Emissions. Under Objective 1.1, gas measurements were completed at a 10,000 cow freestall dairy. Data are being processed to calculate ammonia, methane, nitrous oxide, and carbon dioxide emission rates. Under Objective 1.3, dairy cooperators have been identified and gas measurements were conducted for one week each month at wastewater ponds at two open-lot dairies. Under Objective 1.4, bioaerosol measurements at a large freestall dairy have been completed and published. Under Objective 2.1, sprinkler drift studies were conducted with a portable irrigation boom using irrigation water and a tracer to quantify water drift from various sprinkler types and operating conditions to optimize future experiments with wastewaters.
Airborne endotoxin and microorganism concentrations decrease rapidly downwind from a dairy. Airborne microorganisms could be a human health concerns near dairy farms. ARS researches at Kimberly, Idaho, measured bioaerosol concentrations at a freestall dairy to assess concentration changes downwind from the dairy and assess diurnal and seasonal variations in concentrations. Results showed that airborne endotoxin and bacteria concentrations 150 ft from the dairy could be several-hundred times greater than background concentrations. These concentrations decreased to near background concentrations at 600 ft downwind. Although bioaerosol concentrations did not have a seasonal trend, concentrations did correlate with meteorological factors such as temperature and solar radiation. These results suggest a reduced risk for exposure to bioaerosols as distance from dairy operations is increased, which is useful information for creating offset distances for new residential or commercial developments near dairy farms.
Shao, L., Liu, B., Griffiths, P.R., Leytem, A.B. 2011. Using multiple calibration sets to improve the quantitative accuracy of partial least squares (PLS) regression on open-path fourier transform infrared (OP/FT-IR) spectra of ammonia over wide concentration ranges. Applied Spectroscopy. 65(7):820-824.
Moore, A.D., Olsen, N.L., Carey, A.M., Leytem, A.B. 2011. Residual effects of fresh and composted dairy manure applications on potato production. American Journal of Potato Research. Available: http://www.springerlink.com/content/ek7858uj37088r50/fulltext.html.