Nitrogen Management in Giant Miscanthus Biomass Production in Piedmont Region of North Carolina.

To date in the United States production of biofuels like ethanol has only been economically feasible from food crops high in sugar and starch, such as corn. There are several other crops that can produce biomass from which biofuels like ethanol and biodiesel can be extracted. The need for cheap and sustainable production of biomass is now than ever. This project is focusing on miscanthus biomass production. Miscanthus produces large quantities of biomass for long periods of time (15 – 20 years), hence it’s a dependable source of feedstock for producing ethanol. There are many reasons why Miscanthus is being used as an energy crop, these include: low moisture content of crop if harvested in early spring, this can be as low as 15% by weight. When harvested the crop has a low mineral content, due to the crop being left to recycle its nutrients, this improves fuel quality (Lewandowski and Kicherer, 1995 & Lewandowski et al, 1997). The crop is harvested annually so the farmer have a regular income and to an extent some income security (ORNL, 2006). Late winter or early spring is the ideal time for harvesting the miscanthus as this would allow the above ground stems and leaves to transfer the nutrients to the rhizome in preparation for winter hibernation. Early harvest will give higher yield but the biomass has significant moisture and other unwanted mineral content which makes the processing and conversion to ethanol challenging. Late winter or early spring harvest has the added advantage of reduced fertilizer requirement and better quality feedstock (Heaton et al., 2009).  Giant miscanthus as a bioenergy feedstock has gained importance only in the recent few years and comparatively less research work has been attempted and published on agronomic and nutrient management aspects. Freedom ® variety of Giant Miscanthus from Repreve Reneables was planted in May, 2013 on a Mecklenberg Sandy Loam soil at NC A&T State University Research farm. Five fertilizer treatments [0 (T1), 60 (T2), 120 (T3), 180 (T4) and 240 (T5) Kg N ha^-1) in four replications were adopted for this study. Plots were randomized and miscanthus biomass was harvested at two times, early October, 2013 (fresh) and late January, 2014 (dry). For both fresh (22 t/ha) and dry (12.9 t/ha) biomass fertilizer treatment T3 has given significantly higher yields compared to all other treatments. Average moisture content was determined to be around 40 – 50% after drying the fresh biomass in an oven. This data is from the first growing season of giant miscanthus and the results need to be optimized over the next few growing seasons as miscanthus is a perennial grass which can grow and produce biomass for long period of time.