Water–energy–food (WEF) is fundamental for human survival, with land use profoundly impacting their supply-demand relationships. Integrating land into the WEF nexus is crucial for sustainable development. This study used a pressure–state–response model to establish its water–energy–food–land (WEFL) evaluation indicator system. The entropy method and coupling coordination degree (CCD) were applied to assess the WEFL nexus of Shanxi Province during 2000−2023. The obstacle degree model and Geodetector were utilized to identify internal constraints and external drivers, while the ARIMA model was employed to predict future CCD trends. The results show that (1) the comprehensive evaluation index and CCD increased over time, but overall coordination remained limited (average CCD = 0.575). Most regions were at bare to primary coordination levels, indicating persistent subsystem constraints. The spatial pattern evolved from “high in north and south, low in central region” to “high in north and west, low in south and east.” (2) Energy and land subsystems were the main sources of constraints, while the obstacle degrees of the water and food subsystems increased. External drivers shifted from being dominated by government scale and economic growth to being led by technological innovation and urbanization, with growing interaction between anthropogenic and natural factors. (3) The ARIMA model predicted further CCD improvement to intermediate coordination by 2030, although regional disparities persisted. These results provided a scientific basis for resource management and sustainable development in Shanxi Province.

The 24 solar terms (STs) comprise a traditional Chinese seasonal calendar that has long guided agricultural practices, but their agronomic relevance under observed historical climate change remains uncertain. We assessed 24 STs’ applicability in Shanxi Province using climate records from 23 meteorological stations during 1960–2019. Climate trends were analyzed at the ST scale, and the Decision Support System for Agrotechnology Transfer (DSSAT) CERES-Maize model, calibrated for Denghai 679, was applied to simulate maize phenology and yield for evaluating phenological shifts and sowing-date effects. Results showed that (1) warming was concentrated during Yushui–Qingming and Xiaoxue–Dahan, with sunshine declines across Mangzhong–Xiaoshu and Bailu–Hanlu. Precipitation trends were weak and spatially variable. (2) The calibrated CERES-Maize model reliably reproduced regional yields and phenology. Simulated V3 growth stage, anthesis, and maturity dates advanced by 1.53, 1.88, and 3.11 days per decade, respectively. V3 was associated with early-spring hydrothermal and radiation conditions, while anthesis and maturity were closely associated with summer heat during the STs Xiazhi, Xiaoshu, and Dashu. (3) Model-derived optimal ST/hou sowing windows were Guyu–H2–H3, Xiaoman–H1–H2, and Xiaoman–H2–H3 for Northern, Central, and Southern Shanxi, respectively. Optimized sowing shifted V3 towards Xiaoman–Mangzhong, delayed anthesis from early Xiaoshu to late Dashu–Liqiu, and postponed maturity towards Qiufen, all referring to STs. These findings provide a scientific basis for continued use of the 24 STs in guiding agricultural practices for maize.