A 60-year study covering 205 countries and regions worldwide has systematically uncovered the evolutionary patterns of nitrogen and phosphorus use efficiency (NUE and PUE) in the four major staple crops—rice, wheat, maize, and soybean.

The research, recently published in Nature Communications, finds that despite continued growth in global fertilizer inputs, nutrient use efficiency in major crops has not improved correspondingly and remains generally low. This underscores that "high input, low efficiency" remains a systemic challenge facing global agriculture.

Significant disparities in efficiency were observed across crops and regions, the researchers noted. Rice grown in tropical regions and wheat in temperate zones consistently exhibit relatively higher NUE. In contrast, maize production in major growing regions such as China and the United States follows a distinct "high input-low utilization" pattern, identifying it as a key focus area for optimization.

Notably, phosphorus use efficiency for all four crops is generally below 50%, indicating that crop phosphorus nutrition remains largely dependent on native soil phosphorus pools rather than fertilizers applied in the current growing season.

The study points out that the fundamental bottleneck to agricultural green transformation is not a lack of technology, but rather spatiotemporal mismatches between crop physiological demands, environmental nutrient conditions, and human management practices. Thus, the core of future agricultural optimization should shift from "how to fertilize" to "how to systematically restructure"—redesigning the underlying architecture of agroecosystems through intelligent matching of crops, climate, and soil conditions.

Based on these findings, the research proposes a three-tier parallel systemic optimization pathway: "crop-region-technology." At the crop level, targeted precision fertilization should be implemented for inefficient crop-climate zone combinations. At the regional level, management resources should be prioritized for "efficiency sink" areas based on spatially explicit efficiency distributions. At the technological level, measures including high-nutrient-use varieties, conservation tillage, straw return, and functional microorganism application should be integrated into comprehensive technology packages to boost efficiency and reduce emissions.

The global nutrient efficiency atlas developed in the study not only reveals the core contradiction in agricultural nutrient management but also provides a scientific framework for dynamically diagnosing systemic bottlenecks and simulating management outcomes, the researchers noted.

The research was led by the Institute of Earth Environment of the Chinese Academy of Sciences, and supported by the National Natural Science Foundation of China, the European Union's Horizon Europe Framework Programme, and other sources.