Use of bedding materials in beef bedded manure packs in hot and cool ambient temperatures: Effects on ammonia, hydrogen sulfide, and greenhouse gas emissions

Authors: JADERBORG, JEFFREY - University Of Minnesota; Spiehs, Mindy; Woodbury, Bryan; DICOSTANZO, ALFREDO - University Of Minnesota; Parker, David

Submitted to: Transactions of the ASABE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/16/2021
Publication Date: 7/1/2021
Citation: Jaderborg, J.P., Spiehs, M.J., Woodbury, B.L., DiCostanzo, A., Parker, D.B. 2021. Use of bedding materials in beef bedded manure packs in hot and cool ambient temperatures: Effects on ammonia, hydrogen sulfide, and greenhouse gas emissions. Transactions of the ASABE. 64(4):1197-1209. https://doi.org/10.13031/trans.14291.
DOI: https://doi.org/10.13031/trans.14291

Interpretive Summary: Throughout the upper Midwest, farmers have observed an increase in land prices and fertilizer prices resulting in the increased popularity of confinement feeding facilities such as mono-slope and hoop barns with bedded packs. In these barns, bedding is added weekly or every other week, and a pack of bedding material is allowed to accumulate in the center of the barn. The urine and feces around the edges of the pack is removed. Common bedding materials used are corn stover or wheat straw. The barns are naturally ventilated so a wide range of temperatures can be found in these barns throughout the year. A study was conducted to determine the effect of bedding material and environmental ambient temperature on concentration of ammonia, hydrogen sulfide, and greenhouse gases (methane, carbon dioxide, and nitrous oxide) in air from lab-scaled bedded packs that are designed to simulate a bedded pack barn. The hot treatments were 30 °C (86 °F) and cold treatments were 15 °C (59 °F). Four bedding materials were tested: corn stover, bean stover, wheat straw, and pine wood chips. Producers should evaluate their bedded pack management system and consider potential bedding material being used and bedded pack removal frequency based on seasonal ambient temperatures to reduce overall operation flux emissions. The results were variable. Ammonia and greenhouse gases were higher in hot environments compared to cold environments, while hydrogen sulfide was higher in cold environments. Corn stover bedding resulted in the lowest ammonia emissions, while wheat straw produced the lowest hydrogen sulfide emissions. However, methane was highest from corn stover and bean stover bedding, while carbon dioxide emissions were greatest for wheat straw bedding. Producers need to evaluate which gases they are attempting to control and consider the seasonal barn temperature when selecting bedding materials for their facility.

Technical Abstract: Throughout the Upper Midwest, farmers have observed an increase in land and fertilizer prices resulting in increased popularity of confinement feeding facilities such as mono-slope and hoop barns with bedded packs. Environmental and public pressure has been placed on the agriculture community to reduce ammonia (NH3), hydrogen sulfide (H2S), and greenhouse gas (GHG) emissions from concentrated animal feeding operations (CAFOs). A study was conducted to determine the effect of bedding material (corn stover (CS), bean stover (BS), wheat straw (WS) or pine wood chips (PC)) and environmental ambient temperature (15°C (COOL) or 30°C (HOT)) on NH3, CH4, CO2, N2O, and H2S, flux in air samples collected in headspace above lab-scaled bedded packs. All bedded packs were housed at 18°C for initial 3 weeks of study before being placed in their respective environmental chamber at 15°C or 30°C for the remainder of the 6-wk study. Significant two-way interactions for bedding material by ambient temperature for NH3 flux were observed (p = 0.0094). Ammonia flux was larger at higher ambient temperatures, while CS bedding had the lowest NH3 emissions compared to the other bedding materials. A significant two-way interaction for bedding material by ambient temperature for H2S flux was observed (p < 0.0001) with significantly greater H2S produced in headspace of COOL-BS compared to all other treatments. Additionally, a significant (p = 0.0357) two-way interaction between ambient temperature and age of bedded pack was observed for H2S flux. Hydrogen sulfide flux appeared to be influenced by low bedded pack pH to a greater extent than increases in ambient temperature. Greenhouse gas emissions tended to be higher from bedded packs at HOT ambient temperatures. A significant (p = 0.0422) interaction between bedding material, ambient temperature and age of bedded pack was observed for CH4. Significantly greater CH4 flux was observed in headspace above HOT-BS and HOT-CS at Week 6 compared to all other treatments. A significant two-way interaction for bedding material by ambient temperature for CO2 flux was observed (p = 0.0189). The largest CO2 levels were observed above WS bedding material, regardless of environmental temperature. Nitrous oxide flux decreased over the 6-wk study for all bedded packs, while WS and PC bedded packs produced the greatest N2O flux. The current experiment results indicate feedlot operators maintaining bedded pack facilities will have the greatest reduction in NH3 emission when using CS bedding regardless of ambient temperature. To reduce CH4 emissions, producers should avoid allowing BS and CS bedded packs that are maintained for longer than 6 weeks in HOT 30°C temperatures; frequent cleaning during summer months is recommended. Based on CO2-equivalent of CH4 and N2O, producers should consider PC as option to reduce GHG emission.