Achieving high yield and nitrogen agronomic efficiency by coupling wheat varieties with soil fertility

Wheat breeding has progressively increased yield potential through decades of selection, markedly increased the capacity for food production. Nitrogen (N) fertilizer is essential for wheat production and N agronomic efficiency (NAE) is commonly index used for evaluate the effects of N fertilizer on crop yield, calculated as the difference of wheat yield between N fertilizer treatment and non-N fertilizer treatment divided by the total N application rate. However, the impact of variety on NAE and its interaction with soil fertility remain unknown. Here, to clarify whether and how wheat variety contributes to NAE, and to determine if soil conditions should be considered in variety selection, we conduct a large-scale analysis of data from 12,925 field trials spanning ten years and including 229 wheat varieties, 5 N fertilizer treatments, and a range of soil fertility across China's major wheat production zones. The national average NAE was 9.57 kg kg-1, but significantly differed across regions. At both the national and regional scales, variety significantly affected NAE, and different varieties showed high variability in their performance among low, moderate, and high fertility soils. Here, superior varieties with both high yield and high NAE were identified at each soil fertility fields. The comprehensive effect of selecting regionally superior varieties, optimizing N management, and improving soil fertility could potentially decrease the yield gap by 67 %. Therefore, variety selection based on soil conditions could facilitate improved food security while reducing fertilizer inputs to alleviate environmental impacts.