Fertilizer and Harvest Timing Effects On Miscanthus x Giganteus and Panicum Virgatum.

As the need to find sustainable solutions to our nation’s food and energy resources grows, bioenergy crops are going to play an important part in developing sustainable agricultural practices.  Research focused on how these dedicated energy crops respond to various management practices will be essential to the sustainability of these feedstocks.  Two critical aspects of dedicated perennial energy crops will be harvest timing and fertilizer management.  This research was conducted to gain insight on these management effects on sustainable biomass production of a mature Miscanthus x. giganteus and Panicum virgatum stand in Illinois.  Results conclude that yields were highest during the summer harvest months, but with each sequential harvest throughout the year for three years the yields declined.  Nitrogen fertilizer increased yield for these crops, yet nitrogen fertilization was not able to overcome the effects of harvests prior to senescence.  This resulted in sequential year harvests being negatively affected by the early harvest timing for both Miscanthus x giganteus and Panicum virgatum and biomass harvest after senescence minimized negative impacts of annual harvest on stand longevity. With the knowledge gained from these trials, producers and consumers of these feedstocks can have some useful information in determining the best management practices to follow.