Divergent nitrogen transition pathways during global agricultural development

Reactive nitrogen inputs are crucial for global food production, yet balancing protein availability with limiting agricultural nitrogen pressure poses a significant sustainability challenge. A study analyzed changes in nitrogen use, cropland nitrogen surplus, and protein supply across 130 countries from 1992 to 2022, aiming to identify recurring nitrogen transition patterns during agricultural and economic development.

Countries exhibited diverse trajectories rather than converging towards a common nitrogen transition. Absolute decoupling, characterized by increasing protein supply and declining cropland nitrogen surplus, was observed in 35.4% of countries. Conversely, other nations witnessed relative improvements or increasing nitrogen pressure. As agricultural nitrogen inputs intensified, cropland nitrogen surplus grew more rapidly.

Long-term trajectories revealed contrasting forms of nitrogen system reorganization, ranging from persistently lower-pressure systems to intensifying ones. Absolute decoupling was not systematically associated with a country's development level. While higher-development countries that decoupled generally reduced nitrogen surplus from higher starting levels, they still ended with higher surpluses upon completion.

Therefore, it is possible to increase protein provision while reducing nitrogen surplus, but improvement does not necessarily mean convergence towards low nitrogen pressure.