2008 Joint Annual Meeting (5-9 Oct. 2008): Nitrogen Fertilization for Ethanol Production with Sweet Sorghum and Corn.
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747-4 Nitrogen Fertilization for Ethanol Production with Sweet Sorghum and Corn.



Wednesday, 8 October 2008: 9:15 AM
George R. Brown Convention Center, 360F
Gene Stevens1, Roland Holou2, Matthew Rhine3 and David Dunn3, (1)University of Missouri, PO Box 160, Portageville, MO 63873
(2)Plant Science Division, University of Missouri, Agriculture Building, Columbia, MO 65201
(3)University of Missouri, University of Missouri-Delta Center, PO Box 160, Portageville, MO 63873
Most of the ethanol in the United States is manufactured from corn which typically requires 130 to 225 kg N ha-1 to produce optimum grain yields. Rising natural gas prices have resulted in increased nitrogen fertilizer costs to farmers.  Research was begun at Portageville, Missouri to determine the effects of N fertilization on corn and sweet sorghum used to produce ethanol. A field experiment was conducted on a Tiptonville silt loam soil with sprinkler irrigation. Seven N rate treatments per crop were used with four replications on each crop. Ammonium nitrate was broadcast applied. Corn plots were harvested with a plot combine and sweet sorghum plots were harvested with a sickle mower. In 2007, the highest ethanol amounts were produced with 67 kg N ha-1 on sweet sorghum and 179 kg N ha-1 on corn. The optimum corn yield was 12857 kg ha-1.  Sweet sorghum stalks with 67 kg N ha-1 produced 45.7 Mg ha-1 fresh biomass and contained 329 g solids kg-1.  Water soluble sugars were measured on a fresh weight basis. Sweet sorghum stalks contained 121 g sucrose kg-1, 17 g glucose kg-1, and 14 g fructose kg-1. On a dry weight basis, bagasse contained 436 g cellulose kg-1, 228 g hemicellulose kg-1, and 325 g lignin kg-1. Fermentation from raw sugars and sugars from cellulose in sweet sorghum was done in a laboratory. Assuming 90% recovery from sugars and 85% recovery from cellulose, 4250 liter ha-1 was produced from sugars and 1342 liter ha-1 from cellulose. 
See more of: Crop Response to Nitrogen Fertilizer
See more of: S04 Soil Fertility & Plant Nutrition