Production of Napiergrass as a Bioenergy Feedstock Under Organic Versus Inorganic Fertilization in the Southeast USA
- PDF / 273,437 Bytes
- 10 Pages / 595.276 x 790.866 pts Page_size
- 30 Downloads / 169 Views
Production of Napiergrass as a Bioenergy Feedstock Under Organic Versus Inorganic Fertilization in the Southeast USA Joseph E. Knoll & William F. Anderson & Ravindra Malik & Robert K. Hubbard & Timothy C. Strickland
Published online: 10 April 2013 # The Author(s) 2013. This article is published with open access at Springerlink.com
Abstract Napiergrass (Pennisetum purpureum Schum.) is a high-yielding perennial biomass crop that is well adapted to the Southeast USA where poultry litter is readily available. This research was conducted to compare biomass production and nutrient utilization of napiergrass fertilized with either poultry litter or inorganic fertilizer. Each spring, approximately 100 kg ha−1 of N, 40 kg ha−1 P, and 90 kg ha−1 K were applied as poultry litter or equivalent inorganic fertilizer. Biomass was harvested each winter after senescence. For the first 2 years, dry matter yield did not differ among treatments, but in the third and fourth years, yields declined in all treatments and were lowest in the unfertilized treatment. Biomass N concentration and N removal were greatest in the inorganic treatment. In general, N removal exceeded the amount applied, suggesting that higher application rates may be necessary to maintain yields. Biomass P concentration and total P uptake were greatest in the litter fertilized treatment, demonstrating that napiergrass can remove some of the excess P from applied litter. Soil cores were taken periodically to assess changes in soil properties. After 2 years of production, soil pH in the surface layer (0–15 cm) was lower in the inorganic treatment than in the other treatments. After 4 years, total soil C had increased by an average of 3,180 kg ha−1 though fertilizer J. E. Knoll : W. F. Anderson Crop Genetics and Breeding Research Unit, USDA–ARS, P.O. Box 748, Tifton, GA 31793, USA R. Malik College of Sciences & Health Professions, Department of Natural Sciences, Albany State University, Albany, GA 31705, USA R. K. Hubbard : T. C. Strickland (*) Southeast Watershed Research Laboratory, USDA–ARS, P.O. Box 748, Tifton, GA 31793, USA e-mail: [email protected]
treatments did not differ. Yield declined in all treatments after 4 years and N supplementation is recommended for production in upland fields. Keywords Poultry litter . Nitrogen . Phosphorus . Potassium . Biomass crops . Soil carbon . GRACEnet . LTAR
Introduction Napiergrass (Pennisetum purpureum Schum.), also known as elephantgrass, is a large perennial grass native to tropical sub-Saharan Africa. Because it is a C4 species, napiergrass is capable of producing large quantities of biomass in areas with long warm growing seasons and is being studied as a feedstock for the emerging bioenergy industry in the Southeast USA. Annual DMY over 24 Mg ha−1 has been reported in Florida [1, 2] and Georgia [3]. Research is needed to determine the most efficient, economical, and sustainable means of producing biomass from this crop. Because the per-unit value of raw lignocellulosic biomass is expected to be quite low, p
Data Loading...
