Temporal effects of climate and soil fertility-mediated maize yield and its sustainability: A case study in subtropical China

The sustainability of food production systems requires accurate assessments of the combined impacts of climate change and soil fertility on crop yield. However, a knowledge gap remains regarding the interactions of climate and soil fertility for the determination of crop yield and sustainability. For this study, we investigated how climate and soil fertility affected maize yield and its sustainability over a 30-year experiment on red soil. Seven fertilization treatments were selected (CK (no fertilizer), N (chemical nitrogen), NP (chemical nitrogen and phosphorus), NK (chemical nitrogen and potassium), NPK, M (pig manure), and NPKM (NPK and M)). The link between grain yield and the sustainability yield index (SYI) increased exponentially (p < 0.001). Manure (M and NPKM) improved the concentrations of soil nutrients considerably compared to chemical fertilizer treatments (N, NP, NK, and NPK). The explanatory rates of selected climatic and soil parameters for grain yield and its SYI varied from 56.6% to 66.9%. Soil available nutrients (AP and AK) and total nutrients (TN and TP) regulated grain yield and the SYI at low and high soil fertility, respectively. Redundancy analysis showed a negative correlation between temperature throughout the maize growing season, grain yield, and the SYI, excluding the NPKM treatment. Correlations between temperature, grain yield, and the SYI were reduced as soil fertility increased. Climate (44.0%) and nutrient inputs (40.2%) under chemical and manure fertilization contributed the most to the observed yield. Path analysis explained 68% and 77% of the variations in grain yield under chemical fertilizers and manure treatments, respectively. Additionally, the results suggested that as air temperatures are predicted to rise early maize should be planted earlier and late maize should be planted later to optimize grain yield. Together, this study emphasized that improving soil quality and adjusting planting schedules in agricultural management practices can attenuate the negative impact of climate warming on grain yield sustainable production in the global subtropical regions.