Submitted to: Biomass and Bioenergy
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 30, 2006
Publication Date: December 20, 2006
Citation: Shinners, K.J., Binversie, B.N., Muck, R.E., Weimer, P.J. 2007. Comparison of wet and dry corn stover harvest and storage. Biomass and Bioenergy. 31:211-221. Interpretive Summary: Corn stover, the herbage left over after grain harvest, is a potential source of biomass for fermentation to fuel alcohol, but corn stover is difficult to harvest economically and to store without losses of material. We compared various methods for harvesting, baling, and storage of corn stover in order to identify the best alternatives. Harvesting stover at the time of grain harvest, rather than later in the season, improved stover yield. Storage of the wet (44% moisture) stover in the absence of air resulted in minimal losses of dry matter (less than 4%), while outdoor storage in various types of bale configurations resulted in substantial dry matter losses (up to 18%) and a reduction in stover quality. The results provide information to corn producers on economical storage methods necessary for the development of a corn-stover based biomass industry.
Technical Abstract: Corn stover has great potential as a biomass feedstock, but harvest and storage of this material is challenged by weather conditions at harvest, material moisture, and equipment shortcomings. Field drying characteristics, harvest efficiency and rate, product bulk density, and storage characteristics were quantified for stover harvested and stored in wet or dry form. Only in one case did stover reach dry baling moisture (~20%) within four days of field drying. Conventional hay and forage harvesting equipment produced an average harvested yield of about 30% of the total available stover mass. Harvesting capacity of this equipment was limited by difficulty in gathering shredded stover. The density of chopped or baled stover was less than that typically expected with hay and forage crops. Loss of wet stover ensiled at 44% moisture averaged 3.9% with low levels of fermentation products. Dry stover losses were 3.3% and 18.1% for bales stored indoors and outdoors, respectively. Harvesting wet stover right after grain harvest was timelier and resulted in greater harvesting rate and yield compared to dry stover harvest. Storing wet stover by ensiling resulted in lower losses and more uniform product moisture compared to dry stover bales stored outdoors.