469 Evaluation of Aluminum Sulfate (Alum) As a Feedlot Surface Amendment to Reduce Ammonia, Hydrogen Sulfide, and Greenhouse Gas Emissions from Beef Feedlots

• Published in: Journal of animal science Vol. 96; no. suppl_2; pp. 251 - 252
• Main Authors: Duncan, Z, Spiehs, M J
• Format: Journal Article
• Language: English
• Published: US Oxford University Press 10.04.2018
• Subjects: ammonia; aluminum sulfate; greenhouse gas
• ISSN: 0021-8812; 1525-3163
• DOI: 10.1093/jas/sky073.466

Abstract Ammonia (NH3) and greenhouse gas (GHG) emissions from concentrated feeding operations are a concern. The poultry industry has successfully used aluminum sulfate (Alum) as a litter amendment to reduce NH3 emissions from poultry barns. Alum has not been evaluated for similar uses on cattle feedlot surfaces. The objective of this study was to measure NH3, GHG, and hydrogen sulfide (H2S) emissions from feedlot surface material (FSM) containing 0, 2.5, 5, or 10% Alum over a 32-d period in lab-scale pans containing FSM. Pans containing FSM were sampled every other day for the first 2 wk, and twice weekly thereafter. Results were analyzed as repeated measures using the MIXED procedure of SAS. Average pH of the FSM was significantly lower (P < 0.01) when 2.5, 5, and 10% Alum was included (5.3, 4.4, and 4.2, respectively) compared to 0% Alum (8.1). After 5 d, the pH of FSM containing 2.5% Alum (4.1) was higher (P < 0.01) than FSM with 5 and 10% Alum (3.8 and 3.5, respectively). Ammonia emissions were immediately reduced from FSM that received Alum, with no NH3 volatilization occurring below pH 6.5. Overall NH3, carbon dioxide and nitrous oxide levels were lower (P < 0.01) from FSM containing Alum than those without, with the 10% Alum providing the greatest reduction in emissions. Hydrogen sulfide emissions were higher (P > 0.01) at 0 and 10% inclusion (67 and 104 ppb, respectively) compared to 2.5 and 5% inclusions (56 and 62 ppb, respectively). Total nitrogen content of FSM did not differ among treatments (P < 0.10), but ammonium-nitrogen was highest (P < 0.01) when 10% Alum was used (2.58 g kg-1). Application of Alum to FSM will reduce NH3 and GHG emissions, but H2S emission will increase at the 10% inclusion. Therefore, 5% Alum inclusion appears the most beneficial to reducing NH3 and GHG emissions from cattle feedlots. USDA is an equal opportunity provider and employer.