| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1711036 | Biosystems Engineering | 2015 | 10 Pages |
•Optimal harvesting time for miscanthus was between September and October.•Plant fractions had significant differences in the first 31 d of batch digestion.•Chemical compositions and methane production rates varied.•Significant correlation between methane yield per ha and dry matter yield.
The perennial C4 grass miscanthus was evaluated for use as an energy crop for methane production when harvested green in the autumn. Miscanthus × giganteus (M. × giganteus) and Miscanthus sinensis (M. sinensis) were harvested on five occasions, from August to November 2012. Methane yields from stems and leaves were analysed using batch assay after 90 d digestion. Estimated dry matter yields were highest on 1st October for M. × giganteus and 13th September for M. sinensis. Cellulose and lignin contents were greater with M. × giganteus than M. sinensis and low lignin content in leaves led to rapid degradation during the early periods of anaerobic batch assay. After 90 d of anaerobic digestion, cumulative specific methane yields for M. × giganteus varied for stem and leaf from 285 to 333 and 286 to 314 Nl (normalised litre) kg−1 [VS] and 291 to 312 and 298 to 320 Nl kg−1 [VS] for M. sinensis. Estimated methane yields per ha were positively correlated with the dry matter yields of miscanthus (r = 0.92) and the optimal harvesting time was between September–October. Methane yield at optimal harvest time was estimated as 3.824 × 106 Nl ha−1 (stem) and 1.605 × 106 Nl ha−1 (leaf) for M. × giganteus and 3.507 × 106 Nl ha−1 (stem) and 2.957 × 106 Nl ha−1 (leaf) for M. sinensis. There was a discrepancy between the estimating dry matter yield by sampling single shoots and whole plot harvesting. This needs to be further investigated.
