Methane, carbon dioxide and nitrous oxide fluxes in soil profile under a winter wheat-summer maize rotation in the North China Plain

PLoS One. 2014 Jun 3;9(6):e98445. doi: 10.1371/journal.pone.0098445. eCollection 2014.

Abstract

The production and consumption of the greenhouse gases (GHGs) methane (CH4), carbon dioxide (CO2) and nitrous oxide (N2O) in soil profile are poorly understood. This work sought to quantify the GHG production and consumption at seven depths (0-30, 30-60, 60-90, 90-150, 150-200, 200-250 and 250-300 cm) in a long-term field experiment with a winter wheat-summer maize rotation system, and four N application rates (0; 200; 400 and 600 kg N ha(-1) year(-1)) in the North China Plain. The gas samples were taken twice a week and analyzed by gas chromatography. GHG production and consumption in soil layers were inferred using Fick's law. Results showed nitrogen application significantly increased N2O fluxes in soil down to 90 cm but did not affect CH4 and CO2 fluxes. Soil moisture played an important role in soil profile GHG fluxes; both CH4 consumption and CO2 fluxes in and from soil tended to decrease with increasing soil water filled pore space (WFPS). The top 0-60 cm of soil was a sink of atmospheric CH4, and a source of both CO2 and N2O, more than 90% of the annual cumulative GHG fluxes originated at depths shallower than 90 cm; the subsoil (>90 cm) was not a major source or sink of GHG, rather it acted as a 'reservoir'. This study provides quantitative evidence for the production and consumption of CH4, CO2 and N2O in the soil profile.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Carbon Dioxide / analysis*
  • China
  • Methane / analysis*
  • Nitrous Oxide / analysis*
  • Seasons
  • Soil / chemistry*
  • Triticum*
  • Zea mays*

Substances

  • Soil
  • Carbon Dioxide
  • Nitrous Oxide
  • Methane

Grants and funding

This research is supported by the “Strategic Priority Research Program of Chinese Academy of Sciences” (Grant No. XDA0505050202 and XDA05050601) and the “National Science & Technology Pillar Program” (Grant No. 2012BAD14B07-5). It is also supported by the “National Basic Research Program of China” (Grant No. 2010CB833501); the “National Natural Science Foundation of China” (Grant No. 30970534) and the “Main Direction Program of Knowledge Innovation of Chinese Academy of Sciences” (Grant No. KSCX2-EW-J-5). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.