Water, Air, & Soil Pollution: Focus

, Volume 4, Issue 6, pp 177–186

Carbon sequestration: Do N inputs and elevated atmospheric CO2 alter soil solution chemistry and respiratory C losses?

  • P. Hill
  • C. Marshall
  • H. Harmens
  • D. L. Jones
  • J. Farrar
Article

DOI: 10.1007/s11267-005-3028-6

Cite this article as:
Hill, P., Marshall, C., Harmens, H. et al. Water Air Soil Pollut: Focus (2005) 4: 177. doi:10.1007/s11267-005-3028-6

Abstract

Soil respiration is a large C flux which is of primary importance in determining C sequestration. Here we ask how it is altered by atmospheric CO2 concentration and N additions. Swards of Lolium perenne L. were grown in a Eutric cambisol under controlled conditions with and without the addition of 200 kg NO3 −N ha−1, at either 350 ppm or 700 ppm CO2, for 3 months. Soil respiration and net canopy photosynthesis were both increased by added N and elevated CO2, but soil respiration increased proportionately less than fixation by photosynthesis. Thus, both elevated CO2 and N appeared to increase potential C sequestration, although adding N at elevated CO2 reduced the C sequestered as a proportion of that fixed relative to elevated CO2 alone. Across all treatments below-ground respiratory C losses were predicted by root biomass, but not by soil solution C and N concentrations. Specific root-dependent respiration was increased by elevated CO2, such that belowg-round respiration per unit biomass and per unit plant N was increased.

Keywords

climate changedissolved organic carbonelevated CO2global warmingsoil organic matter

Copyright information

© Kluwer Academic Publishers 2004

Authors and Affiliations

  • P. Hill
    • 1
  • C. Marshall
    • 1
  • H. Harmens
    • 2
  • D. L. Jones
    • 3
  • J. Farrar
    • 1
  1. 1.School of Biological SciencesUniversity of WalesBangor, GwyneddUK
  2. 2.Centre for Ecology and HydrologyBangor, GwyneddUK
  3. 3.School of Agricultural and Forest SciencesUniversity of WalesBangor, GwyneddUK