Nitrogen fertilization mitigates global food insecurity by increasing cereal yield and its stability

Abstract

It is well known that nitrogen (N) fertilization can significantly enhance cereal yield. However, unknowns remain regarding the effects of long-term N fertilization on cereal yield stability, which is as important as cereal yield in addressing the global food crisis. To address this knowledge gap, I synthesized 467 N application studies with duration ≥5 years in croplands across the world. Overall, long-term N fertilization increased both cereal yield (3099 ± 210 kg ha−1 yr−1 [95% CI] under control vs. 5163 ± 303 kg ha−1 yr−1 under N fertilization) and its stability (interannual coefficient of variation: 34 ± 3% under control vs. 28 ± 2% under N fertilization). Soil properties mostly explained the variations of the responses of cereal yield (62%) and its stability (50%) to N fertilization. From fertilizer management perspective, the highest and most stable cereal yield were produced when N was applied with phosphorus and potassium fertilizers. Overall, this study suggests that long-term N fertilization can contribute to relieving the global food crisis by not only enhancing cereal yield but also promoting its stability.