What is 'new nitrogen'?
New nitrogen in the context of food production is reactive nitrogen that was just created (or fixed) from N2 to grow food. Examples of 'new nitrogen' include synthetic fertilizer (which is made with an industrial process) and nitrogen fixed by legumes grown in an agricultural setting.
What is 'recycled nitrogen'?
Recycled nitrogen is existing reactive nitrogen that was created for another purpose but is now being reused (or recycled!) to grow food. Examples include manure, compost, crop residue, and green manure.
How do new and recycled nitrogen inputs compare for organic and conventional food?
The data on nitrogen input types tells a clear story: organic food production uses mainly recycled nitrogen sources whereas conventional production uses mainly new nitrogen sources.
Conventional production of crop and animal products relies heavily on newly created nitrogen, particularly, synthetic fertilizer created through the Haber-Bosch process. In stark contrast, organic production utilizes a wide variety of existing nitrogen sources, including manures, crop residues and composts. These data imply that organic production adds less nitrogen to the global pool per unit product and therefore reduces the impact of human-made nitrogen on the environment.
In the new version of the N-Calculator (coming soon!), you will be able to see whether your food choices rely on recycled nitrogen or if they use newly created nitrogen.