Effect of nitrogen fertilizer application rate on yield, methane and nitrous oxide emissions from switchgrass (Panicum virgatum L.) and reed canary grass (Phallaris arundinacea L.).

Wile, A., Burton, D.L., Sharifi, M., Lynch, D., Main, M., Papadopoulos, Y.A., and Coulman, B.E. (2014). "Effect of nitrogen fertilizer application rate on yield, methane and nitrous oxide emissions from switchgrass (Panicum virgatum L.) and reed canary grass (Phallaris arundinacea L.).", Canadian Journal of Soil Science, 94(2), pp. 129-137. doi : 10.4141/cjss2013-058  Access to full text

Abstract

This 2-yr (2008–2009) study conducted in Truro, Nova Scotia, measured plant biomass production (yield and ash content) and greenhouse gas emissions (methane and nitrous oxide), from the bioenergy crops switchgrass (SG; Panicum virgatum L.) and reed canarygrass (RCG; Phalaris arundinacea L.) receiving spring application of nitrogen fertilizer at 0, 40 and 120 kg N ha-1. In both years, crop yields were unresponsive to N fertilizer. In 2008, SG average yields were greater than RCG producing 7.0 vs. 4.6 Mg ha-1, respectively, while ash content was significantly greater for RCG in both years. Cumulative seasonal (May–November) N2O emissions were<1 kg N2O-N ha-1in 2008 and<0.2 kg N2O-N ha-1in 2009 with crop (SG>RCG) and N fertilizer (N120>N40= N0) effects found in 2008 only. Nitrate exposure was greater for SG in 2008 only, but responded to N fertilization in both years (N120>N0). These crops were net sinks for methane and the magnitude of the sink was not influenced by crop type, N fertilization or year. Despite lower yields, the greenhouse gas intensity calculated for RCG (−2 to 20 kg CO2e t-1biomass) was lower than for SG (8 – 60 kg CO2e t-1 biomass) as a result of lower N2O emissions.

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