title: Effect of urea addition on giant reed ensilage and subsequent methane production by anaerobic digestion.
abstract: The effect of urea addition on giant reed ensilage and sequential anaerobic digestion (AD) of the ensiled giant reed was evaluated. The dry matter loss during ensilage (up to 90 days) with or without urea addition was about 1%. Addition of 2% urea enhanced production of lactic acid by about 4 times, and reduced production of propionic acid by 2-8 times. Besides, urea addition reduced degradation of cellulose and hemicellulose, and increased degradation of lignin in giant reed during ensilage. Ensilage with or without urea addition had no significant effects on the enzymatic digestibility of giant reed, but ensilage with urea addition achieved a cumulative methane yield of 173 L/kg VS, which was 18% higher than that of fresh giant reed. The improved methane yield of giant reed could be attributed to the production of organic acids and ethanol during ensilage.
authors.affiliation: Department of Food, Agricultural and Biological Engineering, The Ohio State University/Ohio Agricultural Research and Development Center, 1680 Madison Ave., Wooster, OH 44691-4096, USA; Key Laboratory of Clean Utilization Technology for Renewable Energy in Ministry of Agriculture, College of Engineering, China Agricultural University, 100083 Beijing, PR China.
authors.forename: Shan
authors.initials: S
authors.lastname: Liu
authors.affiliation: Department of Food, Agricultural and Biological Engineering, The Ohio State University/Ohio Agricultural Research and Development Center, 1680 Madison Ave., Wooster, OH 44691-4096, USA.
authors.forename: Xumeng
authors.initials: X
authors.lastname: Ge
authors.affiliation: Quasar Energy Group, 5755 Granger Rd., Cleveland, OH 44131, USA.
authors.forename: Lo Niee
authors.initials: LN
authors.lastname: Liew
authors.affiliation: Department of Food, Agricultural and Biological Engineering, The Ohio State University/Ohio Agricultural Research and Development Center, 1680 Madison Ave., Wooster, OH 44691-4096, USA.
authors.forename: Zhe
authors.initials: Z
authors.lastname: Liu
authors.affiliation: Department of Food, Agricultural and Biological Engineering, The Ohio State University/Ohio Agricultural Research and Development Center, 1680 Madison Ave., Wooster, OH 44691-4096, USA. Electronic address: li.851@osu.edu.
authors.forename: Yebo
authors.initials: Y
authors.lastname: Li
mesh_terms: D000693:Anaerobiosis / Q000502:physiology; D001421:Bacteria, Anaerobic / Q000378:metabolism*; D056804:Biofuels / Q000382:microbiology; D008697:Methane / Q000378:metabolism*; D006109:Poaceae / Q000737:chemistry* / Q000382:microbiology*; D012820:Silage / Q000382:microbiology*; D014508:Urea / Q000737:chemistry*
chemical_list: D056804:Biofuels; D014508:Urea; D008697:Methane
keywords: Anaerobic digestion; Ensilage; Giant reed; Lactic acid; Urea addition