Global-scale prevalence of low nutrient use efficiency across major crops.

Abstract

Enhancing nitrogen (N) and phosphorus (P) use efficiency (NUE and PUE) is essential for advancing sustainable agriculture and reducing dependency on non-renewable fertilizers. However, the long-term dynamics of NUE and PUE across major crops remain poorly understood at a global scale. Here, we compile a comprehensive global database encompassing 3360 observations across 205 countries to analyze trends in NUE and PUE for major crops from 1961 to 2018. Today, PUE and NUE are still suboptimal, particularly in developing regions, emphasizing the need for context-specific strategies to improve nutrient use efficiency. Global mapping shows that NUE and PUE are highly context-dependent, with variations observed by crop type and region. For instance, rice achieves optimal NUE and PUE in tropical zones, while wheat performs best in temperate climates. Notably, maize continues to exhibit significant nutrient inefficiencies, especially in China and the United States, with considerable N and P surpluses. Taken together, this global analysis provides spatially explicit insights to guide region-specific efforts toward improving nutrient use efficiency, supporting sustainable agricultural practices and reducing global fertilizer dependence.