Traditionally, nitrogen (N) fertilizers have been applied uniformly across entire field while ignoring inherent spatial variation in crop N needs across crop fields. This results in either too little or too much application of N in various parts of the fields. Too little N reduces yields while too much N reduces nitrogen use efficiency (NUE).  To overcome the limitations of traditional N management practices, scientists all over the world have conducted research during the last 15-20 years to develop precision nitrogen management strategies. The objectives of this study were: (i) to analyse the global consumption of N fertilizer and current status of NUE of three major cereal crops – wheat, maize and rice, and (ii) to discuss the scope of improving NUE using precision N management strategies.

Currently, 100 million tonnes of N per annum is applied as fertilizer for agricultural production worldwide, out of which 50% is consumed in production of three major crops – wheat, maize and rice. China is the largest consumer of N fertilizer followed by India, USA and EU; and together these countries consume about 70% of world fertilizer N. While the global NUE for major cereal crops (wheat, maize and rice) is still low, there is a potential of increasing NUE as evidenced by N fertilizer consumption trends and the adoption of precision N management strategies in the USA over the last 10-15 years. Based on current cost of US$1000 per metric ton of N fertilizer, a 10% increase in NUE of these major crops would result in savings of about US$5 billion per year and substantial improvement in environmental quality.