Excessive nitrogen from human activities poses a major threat to water quality, ecosystems, and climate. Net anthropogenic nitrogen input (NANI) is a key indicator that integrates fertilizer use, food and feed trade, crop fixation, and atmospheric deposition to measure the overall nitrogen pressure on a region. While NANI increased rapidly in China before 2010, driven mainly by fertilizer application, less was known about how it changed after 2012—a period marked by major environmental policies, rapid urbanization, and economic restructuring.
To address this gap, researchers from the Chinese Academy of Agricultural Sciences and collaborators analyzed socioeconomic and agricultural data from 31 provincial-level regions in China from 2012 to 2023. They calculated NANI for each province, examined its spatial and temporal patterns, and used partial least squares path modeling (PLS-PM) to explore how urbanization, economic development, and industrial structure adjustment were linked to nitrogen inputs.
The results show that China’s national NANI declined by 22% over the study period, with an annual mean of 5,773 kg N km⁻² yr⁻¹. Nitrogen fertilizer application remained the largest component (39%) but also dropped by 33%, contributing most to the overall decline. Atmospheric deposition fell by 29%, while nitrogen from food and feed imports decreased slightly. Spatially, NANI was consistently higher in the east and lower in the west, with traditional agricultural provinces such as Henan, Jiangsu, and Shandong showing the highest levels.
The study further reveals a striking regional difference. In eastern China, NANI decreased by 26%, and industrial structure adjustment showed a strong negative association with NANI—especially with fertilizer use. In western China, NANI declined by only 13%, and economic development remained more closely linked to nitrogen inputs. According to the authors, these differences suggest that nitrogen reduction in the east has benefited from a shift toward less nitrogen-intensive industries, while the west still needs to balance economic growth with greener agricultural practices.
The authors note that China’s nitrogen trajectory has shifted from continuous growth to a decline, but the pathways differ between regions. They suggest that region-specific strategies are essential—improving fertilizer efficiency in the west, and continuing industrial restructuring and nitrogen-efficient production in the east.
The work titled “Net anthropogenic nitrogen input intensity in China from 2012 to 2023: Spatiotemporal evolution, regional differences, and reduction strategies” was published in Agricultural Environment and Sustainability (published in October 2026).
doi:10.1016/j.ages.2026.100040