Nitrogen fertilizer and landscape position impacts on CO2 and CH4 fluxes from a landscape seeded to switchgrass.

摘要: This study was conducted to evaluate the impacts of N fertilizer and landscape position on carbon dioxide (CO2) methane (CH4) fluxes from a US Northern Great Plains seeded switchgrass (Panicum virgatum L.). The experimental design included three levels (low, 0 kg N ha−1; medium, 56 kg N ha−1; high, 112 kg N ha−1) replicated four times. experiment repeated at shoulder footslope positions. Soil CO2 CH4 were monitored once every 2 weeks May 2010 October 2012. 40% higher than position, similar in both averaged over sampling dates not impacted by rates. Seasonal variations showed highest release uptake summer fall, likely due warmer moist soil conditions. Higher observed winter possibly increased anaerobic However, year (2010–2012) more pronounced impact positions Drought conditions reported 2012, with annual temperature lower moisture long-term average, resulted fall (between 1.3 3 times) 2011 2010. These also promoted net 2012 comparison when there release. Results this conclude that positions, air temperature, content strongly influenced fluxes, whereas direction (uptake or release). comprehensive life cycle analysis would be appropriate environmental associated production under local