Daily Variation of Soil Greenhouse Gas Fluxes In Rubber Plantations Under Different Levels of Organic Fertilizer Substitution

Strategic Insights -

Research conducted at Hainan University in the Longjiang Farm of Baisha Li autonomous county, Hainan Island, has shed light on the diurnal variations and sampling times for accurate estimation of soil greenhouse gas (GHG) fluxes. The study, which focused on rubber plantations with varying levels of organic fertilizer substitution, found significant single-peak daily variation of GHGs in rubber plantation soils. The researchers determined that soil GHG fluxes observed from 9:00-12:00 are closer to the daily average fluxes. The study also found that organic fertilizer substitution influenced soil CO2 and N2O fluxes but had no significant effect on soil CH4 fluxes.

Key Takeaways:

  • The study identified a significant single-peak daily variation of GHGs in rubber plantation soils, with the highest fluxes observed at 9:00-12:00.
  • The optimal observation time for daily average fluxes was found to be 9:00-12:00.
  • Organic fertilizer substitution had a positive effect on soil CO2 and N2O fluxes but no significant effect on soil CH4 fluxes.
  • Flooding excess N2O and CO2 was observed when the substitution ratios exceeded 50% or 75%.
  • Soil CO2 and N2O fluxes were positively correlated with soil temperature and soil moisture in both wet and dry seasons.
  • Soil CH4 fluxes were negatively correlated with soil temperature and soil moisture in both wet and dry seasons.

Statistics:

  • The study involved six treatment groups of rubber plantations with different levels of organic fertilizer substitution (25%, 50%, 75%, and 100%).
  • The soil GHG fluxes were observed by static chamber-gas chromatography for a whole day (24 h) during the wet and dry seasons.
  • The study found significant differences in soil CO2 and N2O fluxes between the control group and the groups with different levels of organic fertilizer substitution.
  • The optimal observation time for daily average fluxes was found to be 9:00-12:00, with the highest fluxes observed at this time.

Sources:

  • NewsRx. New Findings in Global Warming and Climate Change Described from Hainan University (Daily Variation of Soil Greenhouse Gas Fluxes In Rubber Plantations Under Different Levels of Organic Fertilizer Substitution). Global Warming Focus. May 26, 2025; p 2081.
  • Forests, 2025; 16(4):706. (Daily Variation of Soil Greenhouse Gas Fluxes In Rubber Plantations Under Different Levels of Organic Fertilizer Substitution)