|AYADI, FEROUZ - South Dakota State University|
|CORTUS, ERIN - South Dakota State University|
|DJIRA, GEMECHIS - South Dakota State University|
Submitted to: Transactions of the ASABE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/17/2015
Publication Date: 6/30/2015
Citation: Ayadi, F.Y., Cortus, E.L., Spiehs, M.J., Miller, D.N., Djira, G. 2015. Ammonia and greenhouse gas concentrations at surfaces of simulated beef cattle bedded manure packs. Transactions of the ASABE. 58(3):783-795.
Interpretive Summary: Producers that raise beef cattle in confined facilities may apply bedding material to manage the manure and provide comfort for the animal. Some producers let manure and bedding build up to a bedded manure pack that is compacted over time by cattle activity. If it can be determined how bedding material and storage length affect manure composition and emission, producers can make changes accordingly to optimize manure fertilizer value and reduce gaseous emission. These emissions include ammonia (NH3) and the greenhouse gases carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O). We conducted a lab-scale experiment to determine differences in NH3, and CO2, N2O, and CH4 concentrations above simulated beef cattle bedded manure packs based on manure age, bedding material, and temperature. The study was performed for three weeks using temperature/humidity-controlled chambers. Gas concentrations were determined through dynamic flux chamber measurements from the headspace of the simulated bedded manure packs. Fecal material, urine, and bedding were added weekly to twenty four lab-scale bedded manure packs (n=2 per treatment combination). Corn stover or soybean stubble was used as bedding material, at 10°C (50°F) and 40°C (104°F) for 0 to 3, 3 to 6, and 6 to 9 week old bedded manure packs. At fixed intervals, gas samples were taken for NH3 and CO2, N2O, and CH4 with simultaneous pH and temperature measurements from the headspace of simulated bedded manure packs. The study showed that the higher storage temperature of 40°C increased all CO2, N2O, and CH4 concentrations approximately twofold, compared to cooler storage at 10°C, while average NH3 concentrations were almost three times higher in the hot chambers compared to the cold chambers. The CH4 concentrations significantly increased as the age of the bedded manure packs increased, whereas CO2 concentrations increased with age only at 10°C. Ammonia concentrations were significantly higher at 40°C with corn stover as the bedding material compared to soybean stubble. These data suggest seasonal management decisions can impact gas production and release in barns using bedded manure packs. During summer months, NH3, CO2, CH4 and N2O concentrations are expected to increase and when applying corn stover as the bedding, NH3 concentration will likely be higher as when using soybean stubble. During moderate season, CO2 and CH4 concentration are anticipated to increase with longer storage time of bedded manure packs.
Technical Abstract: Bedding is used in livestock operations to facilitate manure management and provide comfort for the animal. The research objective was to determine differences in ammonia (NH3), carbon dioxide (CO2), nitrous oxide (N2O) and methane (CH4) concentrations from simulated beef cattle bedded manure packs (BP) related to storage length (0 to 3, 3 to 6 and 6 to 9 weeks), bedding material (corn stover (CS) or soybean stubble (SB)), and temperature (10°C or 40°C). Bedding, fecal material, and urine were added weekly to twenty four lab-scale BP (n=2 per treatment combination). Static flux chamber samples from the BP headspace were analyzed for CO2, N2O, and CH4 at 0, 24, 46 and 144 h and for NH3 at 0, 5, 9, 23, 34, 46 and 144 h after weekly manure and bedding addition for three consecutive weeks using a doubly repeated measures design. Ammonia concentrations were three times higher above BP housed in the hot chamber (1190 ppm, SE = 47) compared to the cold chamber (400 ppm, SE = 9). Average concentrations for CO2 (6033 ppm, SE = 211), CH4 (42 ppm, SE = 4), and N2O (0.61 ppm, SE = 0.05) were approximately twice as high at 40°C as for CO2 (3902 ppm, SE = 161), CH4 (21 ppm, SE = 2), and N2O (0.39 ppm, SE = 0.03) at 10°C. At 40°C, NH3 concentrations above CS treatments (1388 ppm, SE = 75) were higher than above SB treatments (992 ppm, SE = 51). Overall, a higher storage temperature increased all gas concentrations. Increases in concentration with length of storage were detected for CH4 and CO2, while bedding affected NH3 at 40°C and impacted changes in increase for CH4 concentration. These data suggest seasonal management decisions can impact gas production and release in barns using BP. During hot months, NH3, CO2, CH4 and N2O concentrations are expected to increase and likely higher with CS bedding compared with SB bedding. During moderate seasons, CO2 and CH4 concentration are anticipated to increase with longer storage lengths.