2016/05/31 by Gabriel T. LaHue, Gabriel LaHue, Chris van Kessel +3
Agricultural and Biological Sciences · Environmental Science · #Phosphorus and nutrient management #Soil Carbon and Nitrogen Dynamics #Soil and Water Nutrient Dynamics
paper · doi:10.2134/jeq2015.07.0409
openalex publication_date 2016/05/31 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Agricultural N fertilization is the dominant driver of increasing atmospheric nitrous oxide (N 2 O) concentrations over the past half‐century, yet there is considerable uncertainty in estimates of N 2 O emissions from agriculture. Such estimates are typically based on the amount of N applied and a fertilizer‐induced emission factor (EF), which is calculated as the difference in emissions between a fertilized plot and a zero‐N control plot divided by the amount of N applied. A fertilizer‐induced EF of 1% is currently recognized by the Intergovernmental Panel on Climate Change (IPCC) based on several studies analyzing published field measurements of N 2 O emissions. Although many zero‐N control plots used in these measurements received historical N applications, the potential for a residual impact of these inputs on N 2 O emissions has been largely ignored and remains poorly understood. To address this issue, we compared N 2 O emissions under laboratory conditions from soils sampled within zero‐N control plots that had historically received N inputs versus soils from plots that had no N inputs for 20 yr. Historical N fertilization of zero‐N control plots increased initial N 2 O emissions by roughly one order of magnitude on average relative to historically unfertilized control plots. Higher N 2 O emissions were positively correlated with extractable N and potentially mineralizable N. This finding suggests that accounting for fertilization history may help reduce the uncertainty associated with the IPCC fertilizer‐induced EF and more accurately estimate the contribution of fertilizer N to agricultural N 2 O emissions, although further research to demonstrate this relationship in the field is needed. Core Ideas The IPCC fertilizer‐induced emission factor for N 2 O is based on zero‐N control plots. Many of these zero‐N control plots received fertilizer N inputs 1 to 2 yr earlier. We compared soils with no N inputs (>20 yr) to soils with N inputs until 1 to 2 yr ago. Soils with historical N inputs had higher N 2 O emissions during an incubation. Higher N 2 O emissions were related to increased soil inorganic N and labile organic N.