Compaction effects on greenhouse gas and ammonia emissions from solid dairy manure

Area of Science:

• Agricultural Science
• Environmental Science
• Waste Management

Background:

• Solid dairy manure management is crucial for controlling gas emissions.
• Understanding gas transport within manure piles is essential for developing effective mitigation strategies.
• Greenhouse gases (GHGs) and ammonia emissions from manure contribute to environmental pollution.

Purpose of the Study:

• To investigate gas transport and emission dynamics within solid dairy manure under controlled conditions.
• To evaluate the impact of applied stresses and moisture content on gas emissions.
• To identify key factors influencing greenhouse gas and ammonia release from manure piles.

Main Methods:

• Controlled experiments were conducted to simulate manure pile conditions.
• Fourier-transform infrared spectroscopy was used to monitor concentrations of methane, carbon dioxide, nitrous oxide, and ammonia.
• Gas flux rates were calculated based on measured gas concentrations and transport properties.

Main Results:

• Carbon dioxide was the predominant greenhouse gas emitted across all tested conditions.
• Manure with high mechanical strength and permeability facilitated greater gas transfer, primarily through diffusion.
• Increased moisture content in manure with high water-holding capacity led to a significant reduction in gas emission rates.
• Compaction treatments had a less pronounced effect on gas emission rates compared to moisture content.

Conclusions:

• Moisture content is a critical factor in reducing gas emissions from solid dairy manure.
• Manure properties like mechanical strength and permeability influence gas transport dynamics.
• These findings offer fundamental insights for optimizing waste management practices to minimize environmental impact from dairy manure.