Submitted to: Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: July 25, 2011
Publication Date: October 16, 2011
Citation: Knoll, J.E., Anderson, W.F., Strickland, T.C., Hubbard, R.K. 2011. Production of napiergrass (Pennisetum purpureum Schum) for bioenergy under organic versus inorganic fertilization in the southeast USA. ASA-CSSA-SSSA International Meetings, San Antonio, TX, Oct. 16-20, 2011. CDRom. Interpretive Summary: not required
Technical Abstract: Napiergrass (Pennisetum purpureum Schum.) is being considered for use as a feedstock for the emerging bioenergy industry in the Southeast USA. However, research is needed to determine the most efficient and sustainable means of producing this crop for bioenergy in this region. Poultry litter is a readily available source of nutrients and could be used as a low cost fertilizer for biomass crops. This study was initiated at Tifton, GA in fall 2006 to compare biomass production and nutrient utilization of napiergrass fertilized with either poultry litter or inorganic fertilizer. An unfertilized control was also included. Each year approx. 84 kg N, P, and K/ha was applied as poultry litter or equivalent inorganic fertilizer. Biomass was harvested each winter after senescence. For the first two years, yield differences between the treatments were not significantly different, but in the third and fourth years, yields declined in the control treatment. In the fourth season, the inorganic treatment had slightly higher yield than the poultry litter treatment. In general, yields and total nitrogen removal tended to decline over time. N removal also exceeded the amount applied, suggesting that higher application rates may be necessary to maintain yields. After four years of production, soil cores were taken from each plot to assess changes in soil C and N pools. Poultry litter can be used as a fertilizer for biomass crops in the Southeast, but its high P content may limit its use. Supplementation of N and K with inorganic fertilizer is recommended.