Targeted Nitrogen Management to Increase Cereal Production while Reducing Nitrogen Consumption in India

Nitrogen is the most essential nutrient in crop production but a substantial portion of applied N to the cropland is lost into the environment by means of volatilization, leaching, or emissions causing multiple adverse effects on terrestrial and aquatic systems and on human health. Consumption of Fertilizer-N in India, the second largest consumer of N fertilizer in the world, has increased steadily since 1960s and is expected to further increase in the future to produce more food to meet the projected food demand. However, inequality is the core of the problem with some regions applying more N fertilizer than required leading to negative environmental externalities and other regions applying far less N leading to lower yields and soil mining adding to the vicious cycle of food insecurity. A data-based approach to identify areas of N surplus/N deficit, the magnitude of nitrogen-use-efficiency (NUE) and N harvest gaps helps develop location-specific fertilizer management strategies. Here, we developed a global NUE atlas using various sources of data on N input and N output to show the priority areas of N management work to address the issues of over- and under-fertilization. Adopting this data-based approach and using examples from field and national level analyses, we suggest spatially tailored agronomic, economic, and policy strategies of N management to address food, fertilizer, and climate crisis in India.