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The Center for Native Grasslands Management

Title: Alternative nitrogen for southern switchgrass production
Year: 2010
Author(s): Holmberg, M., Rushing, B., Baldwin, B.
Source Title:
Source Type: Proceedings
pages: 36
Original Publication:  
Abstract: Switchgrass (Panicum virgatum) has become an important biomass crop. Nitrogen is the most abundant element in the atmosphere and is often a limiting factor for plant growth. One of the greatest input costs for crop production is nitrogen. Warm winter temperatures in the southeastern US allow establishment of cool‐season legumes. These legumes have the potential to provide nitrogen to switchgrass, replacing or reducing the need for chemical nitrogen fertilizer. This study was arranged as an RCB with four reps, comparing biomass production of switchgrass plots fertilized with three levels of nitrogen (0, 22.7, and 45.4 kg/ha) and seeded to four clover species: arrowleaf (Trifolium vesiculosum), ball (T. nigrescens), crimson (T. incarnatum), and white (T. repens). Clovers were planted on December 18, 2006 and November 3, 2008, and yield data collected in October, 2007 and 2009, respectively, on already established switchgrass plots. In 2006-07, plots seeded to white (8.96 kgN/ha) and crimson (8.39 kgN/ha) clover produced more switchgrass than 0 kgN/ha (6.54 kgN/ha), but between 22.7 kgN/ha (8.21 kgN/ha) and 45.4 kgN/ha (11.26 kgN/ha). In 2008-09, plots seeded to crimson (17.54 kgN/ha) and ball (17.77 kgN/ha) had switchgrass yields similar to 22.7 kgN/ha (18.72 kgN/ha) and 45.4 kgN/ha (16.91kgN/ha). Crimson clover plots had consistent performance (replacing between 22.7 and 45.4 kgN/ha) both years. Follow-up work is necessary to determine the value of legumes in a low‐input system. Subsequent studies will observe re-establishment of the legume crop from seed/rhizomes to persistence and reseeding requirements.
Publisher: Proceedings of the Seventh Eastern Native Grass Symposium. Knoxville, TN, October 5-8, 2010
Editor(s): C. Harper