Analysis of spatiotemporal heterogeneity of wheat potential yield and the driving factors in Hubei Province

Climate change has induced diverse spatiotemporal alterations in climatic factors, intensifying the spatial disparities in crop yields. Assessing the impact of climatic factors on potential yield is pivotal for comprehending the mechanisms influencing spatial variations in potential yield. This understanding is crucial for strategic crop planning within regions and for mitigating interregional yield disparities. This study used climate data spanning the wheat-growing season in Hubei Province from 1985 to 2021. The validated APSIM-Wheat was employed to simulate the potential wheat yield. Various methods, such as multiple regressions, were employed to assess the impact of different climatic factors on variations in potential yield. These approaches were utilized to analyze the mechanisms underlying the spatial heterogeneity of potential yield. Our results showed that wheat potential yields were ranged from 5068.9 to 7895.3 kg∙hm⁻² with a mean of 7187.6 kg∙hm⁻² in Hubei Province. Over the past 35 years, the mean temperature and total precipitation during the wheat growth period escalated at rates of 0.1 ℃∙(10a)⁻¹ and 13.2 mm∙(10a)⁻¹, respectively, whereas total solar radiation declined at a rate of 123.3 MJ∙m⁻²∙(10a)⁻¹. These shifts in climatic factors exacerbated waterlogging and suboptimal light conditions during the growth period, culminating in diminished wheat production potential. The potential yield declined by an average rate of 422.0 kg∙hm⁻²∙(10a)⁻¹, with heightened precipitation primarily contributing to this reduction, as evidenced by a substantial correlation coefficient of −0.73. Spatially, the potential wheat yields exhibited a pattern of higher yields in the north and lower yields in the south of Hubei Province. The potential yield difference and photothermal quotient disparity between northern and southern wheat were 218 kg∙hm⁻² and 0.06 MJ∙m⁻²∙d⁻¹∙℃⁻¹, respectively. The significant spatial heterogeneity in photothermal quotient emerged as the primary determinant of variations in potential yield, supported by a notable correlation coefficient of 0.82. Due to the uneven spatiotemporal dispersion of photothermal quotient, the average daily growth rate of wheat from jointing to maturity was 28.5 kg∙hm⁻²∙d⁻¹ lower in Jingzhou compared with Xiangyang. This discrepancy consequently led to a lower potential yield in Jingzhou. In summary, climate change has precipitated an overarching decline in the potential wheat yield across Hubei Province. In the context of the prevalent waterlogging and insufficient light conditions in the wheat growth environment of the Jianghan Plain region, the development of wheat varieties with high light utilization efficiency and soil waterlogging resilience is of significance in bridging interregional yield disparities and fostering a comprehensive upswing in regional food production.