Abstract Sustainable soybean production in no‐tillage systems necessitates integrated strategies to enhance yield stability while preserving soil health, particularly in the southeastern United States, where long‐term crop rotation and cover crop data are limited. This study evaluated the crop rotations and cover crops' effect on soybean ( Glycine max L.) yields over 20 years (2002–2021) across five phases (4‐year intervals) at two Tennessee sites: the Research and Education Center at Milan (RECM; Loring silt loam) and the Middle Tennessee Research and Education Center (MTREC; Maury silt loam), both under continuous no‐tillage. Employing a split‐block design with four replications (three at RECM from 2010), the experiment assessed 10 crop sequences at RECM (incorporating corn C, cotton T, and soybean S) and seven at MTREC (C and S), alongside five biocovers: Austrian winter pea ( Pisum sativum subsp. arvense), fallow (control), hairy vetch ( Vicia villosa ), poultry litter (PL: 4.4 Mg ha −1 ), and wheat ( Triticum aestivum L.). Results indicated that CSCS at RECM and CCSC at MTREC significantly outperformed soybean monocropping, with rotations yielding gains of 1.14%–31.64% across phases and sites. PL was the superior biocover, yielding up to 30.66% more than fallow. Legume biocovers showed variable performance but improved over time. Site‐specific differences highlighted RECM's higher yields (24.34%–44.15%) over MTREC. These findings underscore the synergistic benefits of rotations and nutrient‐rich biocovers for resilient, high‐yielding no‐till soybean systems, buffering environmental variability. This long‐term study provides critical evidence for optimizing sustainable agriculture in humid subtropical regions, with implications for policy and practice amid climate variability.
Mirahki et al. (Sun,) studied this question.