Response of “Alamoȁd; switchgrass tissue chemistry and biomass to nitrogen fertilization in West Tennessee, USA

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• 作者：Charles T. Garten Jr.^a ; ^{gartenctjr@ornl.gov} ; Deanne J. Brice^a ; Hector F. Castro^a ; Robin L. Graham^a ; Melanie A. Mayes^a ; Jana R. Phillips^a ; Wilfred M. Post III^a ; Christopher W. Schadt^a ; Stan D. Wullschleger^a ; Donald D. Tyler^b ; Phillip M. Jardine^b ; Julie D. Jastrow^c ; Roser Matamala^c ; R. Michael Miller^c ; Kelly K. Moran^c ; Timothy W. Vugteveen^c ; R. Cesar Izaurralde^d ; Allison M. Thomson^d ; Tristram O. West^d ; James E. Amonette^e ; Vanessa L. Bailey^e ; F. Blaine Metting^e ; Jeffrey L. Smith^f
• 关键词：Switchgrass ; Nitrogen fertilization ; Shoot biomass ; Root biomass ; Carbon stocks ; Nitrogen stocks ; Tissue chemistry ; Nitrogen balance ; Root ; shoot ratio ; C ; N ratio
• 刊名：Agriculture, Ecosystems & Environment
• 出版年：2011
• 出版时间：30 January 2011
• 年：2011
• 卷：140
• 期：1-2
• 页码：289-297
• 全文大小：824 K

文摘

Switchgrass (Panicum virgatum) is a perennial, warm-season grass that has been identified as a potential biofuel feedstock over a large part of North America. We examined above- and belowground responses to nitrogen fertilization in “Alamoȁd; switchgrass grown in West Tennessee, USA. The fertilizer study included a spring and fall sampling of 5-year old switchgrass grown under annual applications of 0, 67, and 202 kg N ha⁻¹ (as ammonium nitrate). Fertilization changed switchgrass biomass allocation as indicated by root:shoot ratios. End-of-growing season root:shoot ratios (mean ± SE) declined significantly (P ≤ 0.05) at the highest fertilizer nitrogen treatment (2.16 ± 0.08, 2.02 ± 0.18, and 0.88 ± 0.14, respectively, at 0, 67, and 202 kg N ha⁻¹). Fertilization also significantly increased above- and belowground nitrogen concentrations and decreased plant C:N ratios. Data are presented for coarse live roots, fine live roots, coarse dead roots, fine dead roots, and rhizomes. At the end of the growing season, there was more carbon and nitrogen stored in belowground biomass than aboveground biomass. Fertilization impacted switchgrass tissue chemistry and biomass allocation in ways that potentially impact soil carbon cycle processes and soil carbon storage.