Nitrogen Use Efficiency in Agricultural Systems

Nitrogen use efficiency (NUE) is a pivotal metric in contemporary agriculture, denoting the fraction of applied nitrogen that is assimilated into crop biomass rather than lost to the environment. Improving NUE is essential to reconcile the dual imperatives of increasing food production and reducing ecological harm. Worldwide, less than half of applied nitrogen is typically recovered by crops, with the remainder contributing to greenhouse gas emissions, eutrophication of water bodies and soil acidification. Advances in precision application, site‐specific management, integration of legumes and cover crops, and policy instruments such as nutrient credit schemes all contribute to raising NUE. Underpinning these advances is an appreciation of the agronomic, environmental and socio‐economic dimensions of nitrogen management, framed within a circular economy that valorises organic residues and recovered nutrients. Emerging challenges include adapting to climate‐driven variability in precipitation, aligning global nutrient flows with regional demands, and translating research insights into farmer practice and regulatory frameworks.

Research from Nature Portfolio

Recent studies have quantified the impact of integrative mitigation packages on global croplands, identifying a suite of management measures that collectively reduce nitrogen losses to air and water by up to 70%, while enhancing crop yields and NUE by 10–80%. Modelling suggests that widespread adoption of these measures could increase food‐system nitrogen productivity by 20% and cut fertiliser requirements by one‐fifth. Complementary meta‐analyses of field experiments have demonstrated that optimised combinations of nutrient, crop and soil management can lift global nitrogen recovery efficiency from an average of 48% to over 75%. These analyses highlight the dominant role of tailored nutrient management and the secondary but still significant benefits of crop diversification and soil health interventions, emphasising the importance of local climate and soil conditions in guiding practice.

Nitrogen Use Efficiency in Agricultural Systems publication trend

The graph below shows the total number of articles in nitrogen use efficiency in agricultural systems across all publications each year (not limited to Nature Index journals).

Technical terms

Nitrogen Use Efficiency (NUE): The ratio of nitrogen taken up by the crop to the total nitrogen applied, reflecting overall resource use effectiveness.

Recovery Efficiency (NUEr): The proportion of applied nitrogen harvested in crop yield, indicating the balance between plant uptake and environmental losses.

Non-point source pollution: Diffuse losses of nitrogen from agricultural fields into waterways and the atmosphere, rather than from identifiable point discharges.

Nitrogen credit system (NCS): A policy mechanism that allocates tradable credits or subsidies to farmers for implementing nitrogen‐saving practices.

Circular nutrient management: An approach that recovers and reuses nutrients from organic waste streams to reduce dependence on synthetic fertilisers.

Machine learning models: Computational algorithms that analyse large datasets to predict agronomic outcomes and inform adaptive nitrogen management.

References

1. Cost-effective mitigation of nitrogen pollution from global croplands. Nature (2023).
2. Energy Demand of Nitrogen and Phosphorus Based Fertilizers and Approaches to Circularity. ACS Energy Letters (2023).
3. Global mean nitrogen recovery efficiency in croplands can be enhanced by optimal nutrient, crop and soil management practices. Nature Communications (2023).
4. Mitigating nitrogen losses with almost no crop yield penalty during extremely wet years. Science Advances (2024).