Nitrogen is essential for life on Earth, but too much nitrogen can accelerate climate change and degrade water, soil and air quality. Existing methods of measuring and monitoring excess nitrogen are expensive, inaccurate and difficult to scale.
Nitrogen balance, or N balance, overcomes those challenges. It provides a user-friendly, scientifically robust way to assess environmental results.
N balance is the nitrogen added to a farm field minus nitrogen removed during harvest. The remaining nitrogen is vulnerable to being lost to the air as nitrous oxide — a powerful greenhouse gas 300 times more potent than carbon dioxide — and to the water as nitrate — a contaminant to drinking water and ecosystems.
Grounded in science, good for farmers
N balance is widely accepted by scientists as the preferred metric for measuring the risk of nitrogen losses to the environment, reflecting impacts on both climate and water quality.
EDF experts partnered with scientists at land-grant universities across the U.S. to determine the “safe zone” — a range of N balance scores in which a farmer is optimizing yields, minimizing excess nutrients and protecting long-term soil health.
N balance focuses on the variables that are within a farmer’s control and is calculated with minimal data that is easy for farmers or their trusted advisers to collect.
By measuring their N balance scores at the field or farm scale year over year and striving to achieve scores in the safe zone, farmers can take steps to reduce their risk of nitrogen losses, all while gaining valuable insights on the economic benefits for their operation.
A breakthrough to eliminate nitrogen losses
EDF scientists also developed two new environmental models that calculate changes in nitrous oxide emissions and nitrate leaching using aggregated N balance scores from across a watershed or sourcing region.
This modeling is a breakthrough that provides a practical and cost-effective way to measure environmental outcomes from agriculture at regional scales. Many food companies currently measure progress toward sustainability goals by counting acres of practice adoption or using complicated, data-intensive models that provide few benefits to farmers.
EDF’s streamlined models provide an easier and more accurate way for food companies, policymakers and other stakeholders to drive measurable environmental progress at scale, for farm and future.
How-to guide for practitioners
EDF's N-Visible framework is an open-source, straightforward way for practitioners to use these scientific advancements and environmental models in real world scenarios.
The four-part N-Visible implementation guide can be used in its entirety or modularly, depending on your needs.
- Why nitrogen balance is a robust and practical way to measure excess nitrogen [PDF] »
- How to calculate nitrogen balance [PDF] »
- What the nitrogen balance safe zone indicates [PDF] »
- How to use nitrogen balance to estimate nitrous oxide and nitrate losses [PDF] »