Simulated management effects on ammonia emissions from field applied manure

Area of Science:

• Agricultural Science
• Environmental Science
• Soil Science

Background:

• Manure nutrient utilization is suboptimal due to ammonia (NH3) volatilization during land application.
• Effective management strategies are needed to mitigate NH3 emissions, especially under Canadian conditions.
• Simulation models offer a validated approach to assess management strategies for diverse field conditions.

Purpose of the Study:

• To utilize the Volt'Air simulation model to estimate NH3 volatilization from manure spreading.
• To evaluate the impact of various manure spreading considerations on NH3 emissions in eastern Canada.
• To quantify the effectiveness of different management strategies in reducing NH3 losses.

Main Methods:

• The Volt'Air simulation model was employed to predict NH3 volatilization.
• Simulations assessed factors including soil liming, time of day, rainfall, and manure incorporation (timing, depth, coverage).
• Model parameters were set for atmospheric conditions typical of eastern Canada.

Main Results:

• Liming increased NH3 emissions by 3.3 kg ha⁻¹ per 0.1 pH unit increase.
• Delaying manure spreading past 0800 h reduced NH3 losses by 1.5 kg ha⁻¹ per hour.
• Rainfall (10mm) at least 20h post-application reduced losses; incorporation within 1h was optimal.
• Increased incorporation depth (5cm) reduced emissions by 4.4 kg ha⁻¹, and 10% greater coverage reduced losses by 2 kg ha⁻¹.

Conclusions:

• The Volt'Air model provides valuable insights into simulating manure management strategies.
• Specific management practices, such as timely incorporation and strategic rainfall utilization, significantly mitigate NH3 emissions.
• Understanding these effects aids in optimizing manure application for improved nutrient use and reduced environmental impact.