Insights from a two‐decade study of crop rotation and biocover impact on yield in no‐till corn

Crop rotation and cover crop (biocover) management can improve the productivity and yield stability of no‐till corn, yet long‐term evidence for humid subtropical silt loams remains limited. This study evaluated corn ( Zea mays L.) grain yield across a 20‐year period (2002–2021) under varying crop sequences and biocovers at two Tennessee locations: the Research and Education Center at Milan (RECM; Loring silt loam) and the Middle Tennessee Research and Education Center (MTREC; Maury silt loam). Treatments were applied as a split‐block (strip‐plot) design. The main plot consisted of repeated 4‐year phases of varying crop sequences containing corn, soybean ( Glycine max L.), and/or cotton ( Gossypium hirsutum L.) (10 sequences at RECM and seven at MTREC). Sub‐plots contained biocover treatments: Austrian winter pea ( Pisum sativum L. sativum var. avense ), hairy vetch ( Vicia villosa L.), wheat ( Triticum aestivum L.), poultry litter, or winter fallow. Data were analyzed using generalized linear mixed models to test management effects and their interactions with phase and location. Across phases and sites, rotation increased yield relative to continuous corn, with corn following soybean showing the most consistent performance across phases. Legume biocovers and poultry litter improved yield relative to fallow in several phases and site‐specific comparisons. In contrast, wheat often reduced yield in early phases, although responses became less negative in later phases. For southeastern United States producers, prioritizing soybean‐based rotations and pairing them with legume biocovers or poultry litter offers a practical pathway to improve corn yield in long‐term no‐till systems in the southeastern United States.