Location: Livestock Bio-Systems
2022 Annual Report
Objectives
Objective 1: Develop pen surface amendments and treatment practices for concentrated animal feeding operations (CAFO) to reduce emissions to the environment, including greenhouse gases (GHG) and odors.
Sub-objective 1.A: Determine the effect of climatic conditions on GHG and odor emission from beef feedlot pen surfaces from various geographical locations.
Sub-objective 1.B: Evaluate the addition of feedlot surface amendment(s) in lab-scale studies to reduce emission of GHG and odorous compounds from beef feedlot pen surfaces from various geographical locations.
Sub-objective 1.C: Evaluate the validity of using electromagnetic induction surveys to predict and mitigate spatially variable feedlot surface GHG and odor emissions.
Sub-objective 1.D: Determine seasonal and annual ammonia transport and dry deposition from beef confinement facilities in and around the livestock facility.
Sub-objective 1.E: Determine NH3 and H2S emissions from swine finishing barns and manure storage based on feed inputs.
Sub-objective 1.F: Continue developing treatment methods for removing certain antimicrobials from wastewater and expand the efficacy of this process for additional pharmaceutically active compounds.
Objective 2: Quantify how long-term manure additions to soil alter soil health as measured by chemical, physical, and biological properties.
Approach
Concentrated animal feeding operations (CAFOs) cause environmental concerns because of the organic, inorganic, pathogenic, and pharmaceutical residues sometimes found in manure and their potential as sources for contamination of soil, surface and groundwater, and air quality. The multifaceted, integrated research proposed herein will provide valuable information for managing the impact of manure on the environment. This work focuses on beef and swine production with an emphasis at the pen because that is where manure is most concentrated, and where management can have a significant impact. A series of experiments are planned to better understand how emission characteristics vary based on climatic conditions and geographical location within the U.S. of open-lot beef pen surface material (PSM). Effects of spatial location within the pen will also be examined. It is anticipated this information will provide insight for the development of precision pen surface management practices for improved environmental control, including the use of pen surface amendments. Nitrogen deposition surrounding the beef feedlot, and the effect of dietary inputs on nitrogen (N) and sulfur (S) outputs from a swine facility will contribute towards larger efforts to model air emissions from livestock production facilities. Additional experiments will develop methods to remove antibiotics and other pharmaceutical compounds in beef, swine, and dairy wastewater prior to land application. The removal of antibiotics and other pharmaceutical compounds will mitigate the potential spread of antimicrobial resistance (AMR) in the environment. Finally, the impacts of manure application as a fertilizer amendment will be examined to better characterize the benefits for improving sustainability of soils for crop production. The unique resources and scientific expertise at the U.S. Meat Animal Research Center (USMARC) will enable successful completion of this plan.
Progress Report
Objective 1: Lab-scale experiments have been conducted to evaluate the effectiveness of three pen-surface amendments – lime, aluminum sulfate (alum), and a microbial-based amendment. Air samples were analyzed for odorous volatile organic compounds (VOC) as well as ammonia (NH3), hydrogen sulfide (H2S), and greenhouse gases including nitrous oxide (N2O), methane (CH4), and carbon dioxide (CO2). The first lab-scale study examined 10% alum, 5% alum, 10% lime, and 5% lime (g g-1 mass basis) treatments. A subsequent study examined low (0.1 g product to 4.5 kg FSM), medium (0.5 g product to 4.5 kg FSM), and high (1.0 g product to 4.5 kg FSM) concentrations of the microbial product. A final study compared 10% alum and the microbial-based product at a concentration of 0.5 g product to 4.5 kg FSM mass.
An on-farm project was initiated in May 2022 to evaluate the effectiveness of a microbial-based pit additive in reducing gas and odor emissions from the underground pit beneath a slatted-floor beef cattle barn. Chemical and physical properties of the stored manure are also being evaluated. The microbial-based pit additive was added to two of the five underground pits in May 2022. Once monthly, just prior to the monthly maintenance addition of the pit additive, air samples were collected from the barn, and manure samples collected from the pit of four of the five pens. Air samples were analyzed for odorous VOC, NH3, H2S, CO2, N2O, and CH4. Manure nutrient content was determined at each sampling. Air samples were analyzed from the stored manure samples at Day 1, 4, 6, and 7 post-collection and analyzed for VOC, NH3, H2S, CO2, N2O, and CH4. Data collection on this project will conclude in November 2022.
A final lab-scale project will start in July to determine the effect of climatic conditions on greenhouse gases (GHG) and odor emissions from beef feedlot pen surfaces from two geographical regions with significant cattle production (Texas and Nebraska). Feedlot surface material (FSM) from Texas and Nebraska feedlots will be evaluated at three moisture levels defined as dry (air-dried), wet (1:2 water-to-FSM ratio), and saturated (1:1 water-to-FSM ratio) and three different ambient temperatures (15, 25, and 35°C). A series of lab-scale studies will be conducted for 14 days each to determine VOC, NH3, H2S, CO2, N2O, and CH4 emissions.
To determine seasonal and annual NH3 transport and dry deposition from beef confinement facilities in and around the livestock facility, scientists have mapped two potential data collection arrays surrounding a 6,000-animal beef feedlot located near Clay Center, Nebraska. Equipment needs and detection capabilities of Ogawa passive NH3 samplers are currently being evaluated.
In collaboration with other ARS scientists, a swine facility in Iowa has been equipped with the necessary sampling equipment and preliminary sampling will begin in the fall of 2022. These initial samples from the swine facility will help better refine the potential array surrounding the beef confinement facility before final installation takes place. To determine NH3 and H2S emissions from a swine finishing barn and manure storage based on feed inputs, one swine barn at a collaborator’s site in Iowa has been fitted with necessary air sampling equipment. Initial sampling is being conducted to determine concentration ranges and effectiveness of the sampling protocol in collecting necessary data. Data collection will begin in the fall of 2022 at the Iowa site and in fiscal year (FY) 2023 at the site near Clay Center, Nebraska.
Objective 2: Quantify how long-term manure additions to soil alter soil health as measured by chemical, physical, and biological properties. Samples were collected and analyzed from a 12 year-long fertilizer study comparing commercial fertilizer with manure to meet the nitrogen needs for corn silage crop that was terminated approximately 10 years ago. Both treatments had a cover crop and a no-cover crop treatment. Preliminary analysis of the data shows significant differences in the chemical, physical and biological properties of the soil for the manure treatments compared to the commercial fertilizer. Summarizing these changes using the Haney Soil Health procedure as a measure indicated the manured treatments with cover crop was greater than the commercial fertilizer treatments. Also, the cover crop treatment appeared to be more important for improving soil health when manure treatments are applied compared to commercial fertilizer treatment. Additional sampling and analysis are planned to better quantify the effects observed.
Accomplishments
1. Manure application method and soil water condition affect emission of volatile organic compounds from beef cattle manure. Limited information is available concerning best management practices for reducing odorous volatile organic compound (VOC) emissions following land application of solid beef manure to crop systems. ARS scientists at Clay Center, Nebraska, conducted a study to evaluate the effects of animal diet, land application method, soil water condition, and time since manure application on odorous VOC emissions from areas on which beef manure had been applied. The largest contributors to odors were heptanoic acid, hexanoic acid, indole, and dimethyl disulfide, which together accounted for 65.5% of the odor. Measurements of VOC were greater from plots where manure was surface applied than from plots with incorporated manure. Emission of sulfide compounds were greater for plots with manure from beef cattle fed a diet containing 30% wet distiller’s grain with solubles compared to cattle fed a diet without ethanol by-products. Rainfall immediately after manure application influenced the type and amounts of VOC that were emitted. Beef producers can now employ effective best management practices for reducing VOC emissions by incorporating manure directly after application and delaying land application if there is a high probability of rainfall.
2. Aluminum sulfate amendments unsuccessful in lowering gas emissions from beef feedlot surface material. Producers need an affordable and effective method of reducing noxious odors and greenhouse gases from beef feedlots. Aluminum sulfate (alum) is widely used in the poultry industry to lower the litter pH, which holds the nitrogen in the litter and prevents volatilization as ammonia (NH3). ARS researchers at Clay Center, Nebraska, determined that application of 5 and 10% alum (g g-1 mass basis) to beef feedlot surface material (FSM) was able to effectively lower the pH of FSM for nearly a month, but NH3 emissions were only significantly reduced for 7-14 days. Total nitrogen content was higher in the FSM that contained alum, which may improve the fertilizer value of the manure. However, these benefits are offset by the significantly higher sulfide emissions that result from lowering the pH and adding sulfurs substrate to the FSM, meaning that the application alum is not an effective feedlot surface amendment for cattle producers.
3. Methane emissions vary temporally and spatially from open-lot beef cattle feedlots. Management of open-lot feedlots to control emissions is a difficult challenge for producers because the deposited manure, a mixture of urine and feces, is subjected to precipitation, solar, wind, heat, and other climatic variables. Over time, the manure pack develops several layers; the thickness of the layers depends on time of deposition, location within the pen, topography, animal activity, and climatic variables. There is a limited understanding on the amount of methane emitted directly from the manure surface in open-lot feedlot pens. A collaborative study was conducted by ARS researchers at Bushland, Texas, and Clay Center, Nebraska, to quantify pen surface emissions during cool and warm seasons. The study revealed that open-lot beef feedlots are a source of greenhouse gas emissions including methane and nitrous oxide. Methane was generated in the lower anaerobic layers of the manure pack. However, methane emissions decreased after rainfall due to methane oxidation or blocking of pore space in the manure layer, and pen surface methane emissions accounted for less than 1% of overall feedlot greenhouse gas as a carbon dioxide equivalent. Therefore, efforts to mitigate greenhouse gas from open-lot beef feedlots should focus on sources with higher percentages of overall greenhouse gas, such as enteric methane, pen surface nitrous oxide, and nitrous oxide from fertilized cropland.
Review Publications
Spiehs, M.J., Woodbury, B.L. 2022. Effect of using aluminum sulfate (alum) as a surface amendment in beef cattle feedlots on ammonia and sulfide emissions. Sustainability. 14(4). Article 1984. https://doi.org/10.3390/su14041984.
Woodbury, B.L., Gilley, J.E., Parker, D.B., Marx, D.B. 2022. Emission of volatile organic compounds as affected by beef cattle diet and soil water content. Transactions of the ASABE. 65(1): 123-133. https://doi.org/10.13031/ja.14587.
Parker, D.B., Casey, K.D., Waldrip, H., Min, B., Woodbury, B.L., Spiehs, M.J., Campbell, T.N., Meyer, B.E., Willis, W.M. 2022. Temporal and spatial variability of methane emissions from Texas open-lot beef cattle feedyard pens. Transactions of the ASABE. 64(6):1781-1794. https://doi.org/10.13031/trans.14672.
