Dicyandiamide and 3,4-dimethyl pyrazole phosphate decrease N2O emissions from grassland but dicyandiamide produces...

Area of Science:

• Agricultural Science
• Environmental Science
• Soil Science

Background:

• Nitrogen fertilizers cause ecological issues like nitrate leaching and greenhouse gas emissions.
• Agricultural soils are significant sources of nitrous oxide (N2O), a potent greenhouse gas.
• N2O emissions result from soil nitrification and denitrification processes.

Purpose of the Study:

• To evaluate nitrification inhibitors (NIs) dicyandiamide (DCD) and 3,4-dimethyl pyrazole phosphate (DMPP) as management tools.
• To mitigate N2O emissions from mineral and slurry fertilization in grassland systems.
• To assess the phytotoxic effects of DCD and DMPP on white clover.

Main Methods:

• Field experiments were conducted on grassland systems (Experiments 1 and 2).
• Laboratory experiments assessed the phytotoxicity of DCD and DMPP on white clover (Experiment 3).
• Soil nitrogen dynamics and N2O emissions were monitored following fertilizer application with and without NIs.

Main Results:

• Both DCD and DMPP maintained soil nitrogen in ammonium form, reducing cumulative N2O emissions.
• DCD significantly decreased N2O emissions but caused phytotoxic effects and yield reduction in white clover.
• Phytotoxicity manifested as chlorosis and necrosis, indicating a nutrient imbalance.

Conclusions:

• Nitrification inhibitors are effective in reducing N2O emissions from fertilized soils.
• DCD poses a risk of phytotoxicity and yield loss in clover, unlike DMPP.
• Careful selection and application of NIs are crucial for sustainable agricultural management.