Beyond waste: Transforming manure into a resource through integrated systems

Area of Science:

• Agricultural Science
• Environmental Science
• Soil Science

Background:

• US livestock generates over 1.27 billion metric tons of manure annually.
• Manure presents both a valuable nutrient resource and significant environmental risks.
• Sustainable manure management is crucial for the livestock industry and environmental protection.

Purpose of the Study:

• To synthesize current knowledge on manure's agronomic and soil health benefits.
• To evaluate environmental risks associated with manure management.
• To critically assess advanced treatment and valorization technologies for manure.

Main Methods:

• Comparative analysis of manure management approaches (land application, stockpiling, lagoons).
• Assessment of advanced technologies: anaerobic digestion, nutrient recovery, biochar co-composting, precision application.
• Evaluation of adoption drivers (regulations, incentives, digital innovations) and barriers (costs, logistics, knowledge gaps).

Main Results:

• Manure offers agronomic and soil health benefits but poses environmental risks (CH4, N2O, NH3 emissions, pathogen fate).
• Advanced technologies show promise for nutrient recovery and resource valorization.
• Regulatory frameworks and economic incentives can drive adoption, but barriers remain significant.

Conclusions:

• Optimizing manure management requires balancing benefits and risks through integrated strategies.
• Further research is needed to address knowledge gaps in emission quantification and site-specific trade-offs.
• Transitioning to a circular agricultural economy necessitates advancing manure management technologies and policies.