title: Evaluation of Optimum Moisture Content for Composting of Beef Manure and Bedding Material Mixtures Using Oxygen Uptake Measurement.
abstract: Moisture content influences physiological characteristics of microbes and physical structure of solid matrices during composting of animal manure. If moisture content is maintained at a proper level, aerobic microorganisms show more active oxygen consumption during composting due to increased microbial activity. In this study, optimum moisture levels for composting of two bedding materials (sawdust, rice hull) and two different mixtures of bedding and beef manure (BS, Beef cattle manure+sawdust; BR, Beef cattle manure+rice hull) were determined based on oxygen uptake rate measured by a pressure sensor method. A broad range of oxygen uptake rates (0.3 to 33.3 mg O2/g VS d) were monitored as a function of moisture level and composting feedstock type. The maximum oxygen consumption of each material was observed near the saturated condition, which ranged from 75% to 98% of water holding capacity. The optimum moisture content of BS and BR were 70% and 57% on a wet basis, respectively. Although BS's optimum moisture content was near saturated state, its free air space kept a favorable level (above 30%) for aerobic composting due to the sawdust's coarse particle size and bulking effect.
authors.affiliation: Department of Animal Biosystems Science, Chungnam National University, Daejeon 305-764, Korea.
authors.forename: Eunjong
authors.initials: E
authors.lastname: Kim
authors.affiliation: Animal Environment Division, National Institute of Animal Science, Jeonju 55365, Korea.
authors.forename: Dong-Hyun
authors.initials: DH
authors.lastname: Lee
authors.affiliation: Department of Animal Resources, College of Life & Environmental Sciences, Daegu University, Daegu 38453, Korea.
authors.forename: Seunggun
authors.initials: S
authors.lastname: Won
authors.affiliation: Department of Animal Biosystems Science, Chungnam National University, Daejeon 305-764, Korea.
authors.forename: Heekwon
authors.initials: H
authors.lastname: Ahn
keywords: Bedding Material; Beef Manure; Moisture Content; Oxygen Uptake Rate; Water Holding Capacity