Soil-climate interactions enhance understanding of long-term crop yield stability

Improving crop yield and stability is crucial for sustainable food production, which is predominantly influenced by climate. Nutrient management mitigates the negative impacts of climate change on yield stability, but little is known about the explanatory capability of climate variables (especially canopy, soil, and nighttime temperatures) and soil nutrient interactions for yield anomalies. This study evaluated the long-term (1992–2020) responses of wheat and maize yields and yield anomalies to various climatic variables under distinct combinations of nitrogen (N), phosphorus (P), and potassium (K) nutrient supplies in the North China Plain. Results showed that NPK treatment improved the stability of relative yield anomalies (RYA) for wheat and maize by up to 65 % compared to the unfertilized control, while negatively affecting the stability of absolute yield anomalies (AYA). Nutrient supply affected the yield stability of maize more than that of wheat. Ground and soil temperatures contributed the most to the yield and yield anomalies, while air temperature was less associated. Models relying solely on climate data explained 34 % and 28 % of the wheat RYA and AYA, respectively, and 44 % and 49 % of the maize RYA and AYA, respectively. Incorporating nutrient-climate interactions improved the model explanatory power to 67 % for wheat RYA and to 62 % for maize RYA. Additionally, annual random effects were less critical in explaining maize yield and yield anomalies but significant for wheat RYA. The nutrient-climate interactions greatly improved the explanatory capability of models to crop yield anomalies, thereby supporting strategies for sustainable food production amidst changing climate.