Targeted management of agricultural nitrogen for tackling air pollution in the Indo-Gangetic Plain and Himalayan Foothill region

Agricultural ammonia emissions from excess nitrogen fertiliser use are a major but under‑addressed contributor to PM₂.₅ pollution across the Indo‑Gangetic Plain and Himalayan Foothills, particularly through the formation of secondary particulate matter during winter smog episodes. This report synthesises evidence from literature, satellite data, and GAINS modelling to show that fertiliser‑derived ammonia contributes an estimated 3.5–6.0 µg/m³ to annual PM₂.₅ concentrations, undermining progress made through controls on combustion sources. It highlights a critical policy mismatch between urban‑focused air quality programmes and predominantly rural ammonia sources, and reviews international best practices for improving nitrogen use efficiency. The report identifies targeted fertiliser management, enhanced‑efficiency products, and incentive‑based schemes such as PM‑PRANAM as cost‑effective opportunities to align agricultural, air quality, and fiscal objectives. It concludes that meaningful progress toward the region’s 35‑by‑35 clean air goal will require explicit integration of agricultural ammonia mitigation into airshed‑based air quality strategies, supported by stronger institutional coordination and regional cooperation.