Soil N₂O Emissions from Specialty Crop Systems: A Global Estimation and Meta-analysis

Authors

• Lidong Li, Colorado State University-Fort CollinsFollow
• Mu Hong, Colorado State University-Fort Collins
• Yao Zhang, Colorado State University-Fort CollinsFollow
• Keith Paustian, Colorado State University-Fort CollinsFollow

ORCID IDs

Li https://orcid.org/0000-0001-5420-260X

Hong https://orcid.org/0000-0002-0932-1500

Zhang https://orcid.org/0000-0002-2669-1378

Paustian https://orcid.org/0000-0001-5262-5596

Document Type

Article

Date of this Version

2024

Citation

Global Change Biology (2024) 30: e17233

doi: 10.1111/gcb.17233

Comments

Open access

License: CC BY-NC-ND 4.0

Abstract

Nitrous oxide (N₂O) exacerbates the greenhouse effect and thus global warming. Agricultural management practices, especially the use of nitrogen (N) fertilizers and irrigation, increase soil N₂O emissions. As a vital sector of global agriculture, specialty crop systems usually require intensive input and management. However, soil N₂O emissions from global specialty crop systems have not been comprehensively evaluated. Here, we synthesized 1137 observations from 114 published studies, conducted a meta-analysis to evaluate the effects of agricultural management and environmental factors on soil N₂O emissions, and estimated global soil N₂O emissions from specialty crop systems. The estimated global N₂O emission from specialty crop soils was 1.5 Tg N₂O-N year⁻¹, ranging from 0.5 to 4.5 Tg N₂O-N year⁻¹. Globally, soil N₂O emissions exponentially increased with N fertilizer rates. The effect size of N fertilizer on soil N₂O emissions generally increased with mean annual temperature, mean annual precipitation, and soil organic carbon concentration but decreased with soil pH. Global climate change will further intensify the effect of N fertilizer on soil N₂O emissions. Drip irrigation, fertigation, and reduced tillage can be used as essential strategies to reduce soil N₂O emissions and increase crop yields. Deficit irrigation and non-legume cover crop can reduce soil N₂O emissions but may also lower crop yields. Biochar may have a relatively limited effect on reducing soil N₂O emissions but be effective in increasing crop yields. Our study points toward effective management strategies that have substantial potential for reducing N₂O emissions from global agricultural soils.