9. Conclusions and Summary

The sustained European interest in miscanthus suggests that this novel energy crop deserves serious investigation as a possible candidate biofuel crop for the United States alongside switchgrass (Table 1). Switchgrass may show some advantages over miscanthus (notably lower establishment costs from seed and being a native grass species), but miscanthus is worthy of consideration, at least for certain niche applications.

To date, no agronomic trials or trial results for miscanthus are known from the conterminous United States, so its performance under U.S. conditions is virtually unknown. Limited experience has been gained by the USDA/NRCS Plant Materials Center in Michigan, using an ornamental genotype of Miscanthus sinensis for vegetative barriers against wind erosion and run-off. Plantings in Ohio, Michigan, and southern Indiana established successfully, but those in Wisconsin did not work; limited experience has also been obtained in Louisiana (D. Bergdorf, personal communication). Small-scale Canadian trials of Miscanthus x giganteus began in 1997-1998 outside Montreal (lat. 42.5 N), with initial annual yields at spring harvest of 10-11 t/ha dry weight (R. Samson, personal communication).

Speculating from European data on small plots in agricultural experimental stations, the crop may attain as much as 25 t/ha (10 t/acre dry weight) by fall, but it is usually harvested in early spring, after nutrient recycling and drying has taken place -- by which time the yield has reduced to about 15 t/ha (6 t/acre dry weight). Over large areas, under typical agricultural practices, an average of about 8t/ha (3t/acre dry weight) may be expected at harvesttime. The European conditions for these trials range from lat. 50 N to 37 N (roughly from North Dakota to Kentucky, but note that the European climate tends to be warmer and more moderate at the same latitudes than the climate in the United States). Average annual temperatures and rainfall for the European trials range from 7.5 C to 17.5 C (45-63 F), and 500-1000 mm (20-40 in.), with irrigation at the warmer, more southern latitudes. Fertilizer needs appear to be relatively low, depending upon local soil fertility. As with most of the new bioenergy crops, there seems to be a steep "learning curve." Costs are expected to fall and uncertainties to be reduced as first demonstration trials and then commercial plantings become more widespread. Establishment costs appear to be fairly high at present (a wide range is reported from different European countries), although these may be expected to fall as improved management techniques are developed.