Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 9/2/2013
Publication Date: 11/6/2013
Citation: Read, J.J., Adeli, A., Anderson, W.F. 2013. Nutrient removal and allocation in napiergrass treated with swine lagoon effluent. Agronomy Abstracts, American Society of Agronomy Meetings, November 3-6, 2013, Tampa, FL. CD-ROM.
Technical Abstract: Animal waste in Mississippi is typically disposed of by application on subtropical forage grasses, but yield data using this management on napiergrass (Pennisetum purpureum Schum.) is lacking. Napiergrass is a dual-purpose, perennial forage and bioenergy crop candidate for the lower southeastern USA. This research determined yield of biomass and nutrients in ‘Merkeron’ napiergrass grown in a swine-effluent spray field located in north-central Mississippi. Regular applications of swine effluent from April to October provided approximately 318 kg N, 47 kg P, and 470 kg K per ha annually. Final biomass was determined in November and tillers (n=4 in each of four plants) were harvested biweekly beginning in May. A 17% increase in biomass from approximately 35 Mg/ha in 2011 to 41 Mg/ha in 2012 was associated with a 69% increase in tiller number per plant (range = -10 to 130%). Estimates for N, P, and K uptake in 2011 were approximately 380, 68, 862 kg/ha, respectively, and increased considerably in 2012 to approximately 458, 82, and 978 kg/ha, respectively. Leaf and stem contents of N and K (g tiller-1) reached their maximum levels in late-September to mid-October, when approximately 0.8-1.0 g more N and 3.0-3.8 g more K were allocated to stems, as compared to leaves. These results are consistent with reports of high K uptake in napiergrass, and the need for regular applications of conventional N-P-K fertilizer to enable rapid growth and high biomass yields.