1) Miscanthus Fertilization Trials.

In the last 20 years, a great deal of interest has been given to the C4 perennial grass Miscanthus x giganteus as an emerging bioenergy crop. High aboveground net primary productivity on a per area basis and relatively low fertilizer input requirements compared with other annual crops are valuable characteristics of this species. The amount of fertilizer needed to maintain high productivity of Miscanthus largely depends upon soil, climate and management conditions which make generalized best management recommendations difficult. E.G., results of growth response to N in fertilization studies have been inconsistent both in the US and abroad. This trial was conducted as a part of a larger regional feedstock partnership with the objective of generating appropriate fertilization recommendations for Miscanthus in various regions of the US. A multi-year study was conducted in Gretna, VA with N fertilization rate (three levels: 0, 60 and 120 kg N ha^-1) as the sole treatment factor. Plots were fertilized in April or May and plant heights were measured during the growing season once a month from April/May through November. Biomass and morphological data (e.g., stem length and diameter, number of leaves and nodes) were collected in December. Unfertilized plants were shorter during the growing season until time of inflorescence emergence, with small to none differences between moderate and high N rates. Biomass yields from fertilized plots were generally greater than from control plots but similar for the two N-added fertility treatments. Results indicate that moderate N rates are sufficient to maximize Miscanthus x giganteus production in the Piedmont region of Virginia.