Nitrogen flow analysis in Spain: Perspectives to increase sustainability

Area of Science:

• Environmental Science
• Agricultural Science
• Circular Economy

Background:

• Nitrogen (N) is crucial for agriculture but excessive use causes environmental issues like eutrophication.
• The Haber-Bosch process for N fertilizer is energy-intensive, and Europe, including Spain, relies heavily on imports.
• Sustainable alternatives and efficient management aligned with circular economy principles are needed.

Purpose of the Study:

• To conduct a nitrogen flow analysis (NFA) for Spain in 2016.
• To assess N interactions and flows within agriculture and waste management systems.
• To analyze N-use efficiency and the impact of diet on the N cycle.

Main Methods:

• Nitrogen flow analysis (NFA) for Spain (2016).
• Sub-models for agriculture and waste management systems.
• Inclusion of country-specific data for food and non-food flow systems.

Main Results:

• Spain imported 2142 kt N/y, with 43% accumulating in soils and water bodies.
• Agriculture caused the largest N losses (724 kt N/y to water, 132 kt N/y to soils).
• Wastewater treatment plants (WWTPs) discharged 49 kt N/y, representing 79% of total reactive N loss to water.

Conclusions:

• Significant nitrogen accumulation and losses occur in Spain, primarily from agricultural activities.
• Current wastewater treatment and biosolids management show limited recovery for fertilization.
• Improving N-use efficiency and considering dietary impacts are critical for sustainable nitrogen management.