Influence of particle size and packaging on storage dry matter losses for switchgrass

The objective of this study was to estimate the storage dry matter (DM) losses for switchgrass bales that were preprocessed using an industrial baler technology prior to storage with three particles sizes of feedstock and two types of bale wraps. Mixed models were used to test difference in DM losses across the particle sizes, wrap materials, and storage days. Response functions were also estimated to determine DM losses for each particle size and wrap material at storage over time. DM losses were found to be different across particle size, wrap material, and storage period. Specifically, the DM losses were lower when the particle size of switchgrass baled decreased from full length to less than two centimeters. The results show switchgrass bales stored at the smallest particle size had lower DM losses than bales stored at the full length of feedstock. Also, applying additional film wrap that completely covers the net wrapped bale reduced DM losses relative to bales wrapped only in net. Furthermore, storage DM losses of preprocessed switchgrass bales increased linearly with days in storage. Our findings suggest that applying both net and film wrap to switchgrass bales composed by a particle size less than two centimeters can reduce DM losses during storage. Economic analysis indicates the price of switchgrass was also important in the choice of storage method for switchgrass. The results provide valuable insight into improving feedstock logistics and the feasibility of the advanced biofuels industry. (C) 2014 Elsevier Ltd. All rights reserved.