Research Highlights

Recent highlights of our science

Improved modeling of soil nitrogen loss

August 1, 2015

Objective

  • Improve prediction of soil nitrogen losses via advection (i.e., nitrate) and gaseous emissions (i.e., N2O and N2)
  • Improve the ACME Land Model (ALM) numerical representation of nutrient competition coupled with abiotic processes.

Approach

  • We modified the ALM nitrogen competition module with the Equilibrium Chemistry Approximation (ECA) approach that represents the multi-substrate, multi-consumer environment.
  • Advective nitrate losses and competition with biotic consumers (e.g., plants) were more realistically represented.

Results/Impacts

  • As shown in the upper left panel, the current versions of ALM and CLM4.5 poorly represent the gaseous proportion on nitrogen losses (fdenit).
  • The bottom two panels show the dramatic improvements in partitioning of N losses with our ECA and advection changes.
  • We are integrating these concepts into ALMv1.

Zhu, Qing, and William J. Riley. August 1, 2015. “Improved Modelling of Soil Nitrogen Losses.” Nature Clim. Change, 5(8):705–706. doi:10.1038/nclimate2696.