|Fransen, Steve - WASHINGTON ST UNIV|
|Smith, J - WASHINGTON ST UNIV|
Submitted to: American Society of Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: May 26, 2007
Publication Date: October 30, 2007
Citation: Collins, H.P., Fransen, S., Smith, J.L. 2007. Carbon Sequestration under Irrigated Switchgrass Production. American Society Agronomy Abstracts, 2007 International Meetings, New Orleans, LA, Nov 4-8, 2007, on CD, © Copyright 2007, ASA-CSSA-SSSA.I Technical Abstract: Innovative strategies to mitigate threats of global climate change warrant evaluation of crops capable of producing high biomass for both energy generation and promotion of soil organic matter through C sequestration. Bioenergy crops have the potential to reduce the rate of atmospheric CO2 enrichment as well as supply a portion of U.S. energy needs. Perennial herbaceous plants (e.g. switchgrass) have been shown to improve soil quality, enhance nutrient cycling, improve wildlife habitat and sequester C. However, none of this work has been conducted in the PNW. With the increased likelihood of a bio-based energy industry being created in the Columbia Basin of Eastern WA (proposed 115-M L biodiesel and 1100–M L of ethanol facilities), we initiated research (2003) on the production of oilseeds and biomass crops and are just now evaluating secondary benefits of environmental improvement through C sequestration and removal of soil nutrients. Above ground biomass annual yields averaged 20.4 16.9 and 14.5 Mg dry matter ha-1 for the Kanlow, Shawnee, and Cave in Rock varieties, respectively. The cumulative export of C and N from the field at harvest averaged 15.2 Mg C ha-1 and 427 kg N ha-1 among varieties over two years of production. Root biomass produced after three seasons averaged 9.2 Mg ha-1 to a depth of 1-m, with an estimated C pool of 4.1 Mg C ha-1 m-1. On average 24% (~1.8 Mg C ha-1) of the soil C has been derived from the inclusion of switchgrass.