Controlled-Release/Stable Nitrogen Fertilization Reduces Greenhouse Gas Emissions and Improves Vegetable Yields

A recent five-year field experiment conducted by researchers from Qingdao Agricultural University in China has demonstrated the efficacy of controlled-release/stable nitrogen (N) fertilization in reducing greenhouse gas emissions and increasing lettuce yield in long-term fixed-position vegetable rotation fields. The study, which was supported by various organizations including the Natural Science Foundation of Shandong Province, found that controlled-release/stable N fertilization resulted in lower nitrous oxide (N2O) and carbon dioxide (CO2) emissions compared to traditional farming practices.

Key Takeaways:

• The study employed six distinct treatments for N fertilization, including a control without N fertilizer and optimized application of urea with and without the supplementation of 3,4-dimethylpyrazole phosphate (DMPP) as a N inhibitor.
• The results showed that the treatments using controlled-release/stable N fertilization emitted 12.2%-56.7% less average annual cumulative N2O and 1.31%-10.0% less CO2 than the treatment with optimized application of urea without DMPP.
• No significant seasonal or interannual variability was observed in N2O and CO2 emissions from the controlled-release/stable N fertilization treatments.
• The observed phenomena were attributed to fluctuations in soil ammonium-and nitrate-N contents.
• The study concluded that long-term controlled-release/stable N fertilization resulted in reduced field N loss, benefitting vegetable yields without increasing CO2 emissions and highlighting the application potential of this technique for sustainable agricultural production.

Statistics:

• The study found that the treatment using polyurethane-coated urea at 320 kg N ha-1 with supplementation of 1.0 kg ha-1 DMPP emitted 45.1% less average annual cumulative N2O and 7.3% less CO2 than the treatment with optimized application of urea without DMPP.
• The treatment using polyurethane-coated urea at 320 kg N ha-1 without DMPP emitted 26.3% less average annual cumulative N2O and 3.9% less CO2 than the treatment with optimized application of urea without DMPP.
• The study observed that the controlled-release/stable N fertilization treatments resulted in a 10.8% increase in lettuce yield compared to the traditional farming practices.

Sources:

• Fangli Wang et al. Five-year Controlled-release/stable Nitrogen Fertilization Reduces Field Nitrogen Loss Without Increasing Carbon Dioxide Emissions In a Vegetable Rotation System. Pedosphere, 2025;35(4):741-750.
• NewsRx. Findings on Chemicals and Chemistry Reported by Investigators at Qingdao Agricultural University (Five-year Controlled-release/stable Nitrogen Fertilization Reduces Field Nitrogen Loss Without Increasing Carbon Dioxide Emissions In a Vegetable ...). Global Warming Focus. August 4, 2025; p 1329.