Use of wood-based materials in beef bedded manure packs: 1. Effect on ammonia, total reduced sulfide, and greenhouse gas concentrations

The objectives of this study were to determine the effect of using corn stover or three different wood-based bedding materials (kiln-dried pine wood chips, dry cedar chips, or green cedar chips) on airborne concentrations of NH₃, total reduced sulfides (TRS), CO₂, CH₄, and N₂O above lab-scaled bedded manure packs. Four bedded packs of each bedding material were maintained for two 42-d periods. Airborne NH₃, TRS, CO₂, CH₄, and N₂O were measured weekly. Bedded packs containing dry or green cedar had lower concentrations of NH₃ (350.8 and 357.3 mg m^-3, respectively; P < 0.05) than bedded packs containing pine chips or corn stover (466.0 and 516.7 mg m^-3, respectively). Airborne CO₂ was also lower from bedded packs containing dry and green cedar (1343.7 and 1232.3 mg m^-3, respectively; P < 0.001) compared with bedded packs containing pine chips or corn stover (2000.2 and 1659.8 mg m^-3, respectively). Air samples from bedded packs containing green cedar chips had a higher (P < 0.01) concentration of CH₄ than bedded packs containing dry cedar chips, corn stover, or pine chips at Day 35 and 42. Initially, TRS concentration was similar among all bedding materials; at 28 to 42 d, TRS was higher (P < 0.001) from bedded packs containing the cedar products. Airborne N₂O was similar (P = 0.51) for all bedding materials. Pine chips and cedar products can be adequate substitutes for corn stover in deep-bedded barns, but cedar bedding may need to be removed more frequently.