Study on Genetics Reveals Insights into Nitrogen Loss and Associated Microbial Gene Expression in Soils

Strategic Insights -

Research conducted at Hefei University of Technology in Hefei, People's Republic of China, has shed light on the complex mechanisms involved in nitrogen loss in soils. The study, titled "Effect of Fe (III) Addition on Ammonium Loss and Associated Microbial Gene Expression in Soils," used a response surface methodology to evaluate the combined effects of temperature, Fe (III) contents, NH4+-N contents, and soil-liquid ratio on ammonium loss in soils. The research found that the maximum NH4+-N loss was 86.1% under specific conditions, and the prediction result was similar to experimental data. The study also explored the microbial mechanisms behind nitrogen transformation and quantified functional genes related to nitrification and denitrification.

Key Takeaways:

  • The study used a response surface methodology to evaluate the combined effects of temperature, Fe (III) contents, NH4+-N contents, and soil-liquid ratio on ammonium loss in soils.
  • The maximum NH4+-N loss was 86.1% under the conditions of 17.0 °C, 0.772 g·kg-1 Fe (III), 21.9 mg·kg-1 NH4+-N, and soil: liquid ratio of 1:1.
  • The prediction result was similar to experimental data, with NH4+-N loss at 83.2% under the condition of 25 °C, 0.723 g·kg-1 Fe (III), 20 mg·kg-1 NH4+-N, and soil-liquid ratio of 1:1.
  • The N2O flux reached its minimum value of 8.35 mg·m²·h-¹ under the experimental conditions, correlating with gene copy numbers for ammonia-oxidizing bacteria ammonia monooxygenase subunit A gene (AOB-amoA), and nitrite reductase genes (nirK) at maximum values of 4.5 x 10^5 and 4.8 x 10^5 copies·g-1, respectively.
  • NH4+-N loss resulted from multiple interacting processes beyond ammonia-oxidizing bacteria (AOB) and ammonia-oxidizing archaea (AOA) mediated oxidation.

Statistics:

  • Maximum NH4+-N loss: 86.1% (under specific conditions)
  • Prediction result (experimental data): 83.2% (under specific conditions)
  • N2O flux: 8.35 mg·m²·h-¹ (under experimental conditions)
  • Gene copy numbers for ammonia-oxidizing bacteria ammonia monooxygenase subunit A gene (AOB-amoA): 4.5 x 10^5 copies·g-1
  • Gene copy numbers for nitrite reductase genes (nirK): 4.8 x 10^5 copies·g-1

Sources:

  • "Effect of Fe (III) Addition on Ammonium Loss and Associated Microbial Gene Expression in Soils." BioResources, 2025, 20(4), 8713-8724. (BioResources - https://bioresources.cnr.ncsu.edu/).
  • Liyu Cheng, Hongjie Zhu, Weihao Xing, Benjun Zhou. "Effect of Fe (III) Addition on Ammonium Loss and Associated Microbial Gene Expression in Soils." BioResources, 2025, 20(4), 8713-8724.
  • The publisher for BioResources is North Carolina State University.