Small-scale integrated farming systems can abate continental-scale nutrient leakage

Area of Science:

• Agricultural Science
• Environmental Science
• Nutritional Science

Background:

• Beef production is resource-intensive, contributing to nutrient pollution via synthetic fertilizer use.
• Alternative agriculture models aim to improve nutrient cycling and mitigate environmental impacts.
• The dietary potential and environmental viability of livestock-centric alternative models remain underexplored.

Purpose of the Study:

• To evaluate nitrogen-sparing agriculture (NSA) as a viable alternative to the current US food system.
• To assess the environmental and dietary implications of a mixed-use NSA model focused on nitrogen management.

Main Methods:

• A specific model of mixed-use NSA was devised, integrating plant-based food production, forage cultivation, and intensive beef operations.
• The model forgoes synthetic fertilizers, relying on manure and nitrogen fixers for nutrient input.
• Simulations were based on deployment across high-quality US cropland, assessing dietary output, protein delivery, and environmental metrics.

Main Results:

• NSA could support a diverse, high-quality national diet superior to the current US diet.
• The model allows for 70%-80% of current beef consumption levels.
• NSA reduces fertilizer use by approximately 60% and total greenhouse gas emissions by about 10%.

Conclusions:

• Nitrogen-sparing agriculture presents a potentially viable and scalable alternative to the current US food system.
• NSA offers significant environmental benefits, including reduced fertilizer use and greenhouse gas emissions.
• Successful implementation requires a substantial shift towards increased reliance on plant-based foods.