Cereal rye (Secale cereale L.) as a cover crop can be an effective nonchemical tool for waterhemp [Amaranthus tuberculatus (Moq.) Sauer] suppression in crop production. Previous studies have evaluated A. tuberculatus suppression by cereal rye as part of weed management programs but have not investigated the underlying mechanism of suppression by the cover crop. This study aimed to investigate the effect of cereal rye biomass on A. tuberculatus emergence and development, and on soil environmental parameters (temperature, moisture, and light transmittance) that are key triggers of A. tuberculatus germination to elucidate the mechanism of suppression by the cover crop. A dose–response study was conducted under field conditions in Brooklyn and Janesville, WI, from 2021 to 2023. Cereal rye biomass from a fall-planted field was harvested at anthesis in the spring and dried to constant weight at 60 C to provide 0.0, 0.6, 1.2, 2.4, 4.8, 7.2, 9.6, and 12.0 Mg ha−1 of dry biomass that was evenly distributed over 1.9 m−2 plots. Increasing cereal rye biomass reduced A. tuberculatus height, biomass, and density. An average ED50 of 5.2 Mg ha−1 of biomass was needed to reduce A. tuberculatus density by 50%. Low levels of biomass (≤2.38 Mg ha−1) augmented A. tuberculatus density due to an increase in soil moisture underneath the mulch compared with bare soil. Cereal rye biomass decreased the amount of sunlight reaching the soil, which resulted in lower mean soil temperature and temperature amplitude throughout the day (9.3 and 2.7 C temperature amplitude at 0 and 12.0 Mg ha−1, respectively). Prevention of A. tuberculatus germination by this thermal effect is likely the main mechanism of A. tuberculatus suppression from the cereal rye cover crop. Our results support biomass from cereal rye cover crop effectively suppressing A. tuberculatus and contributing to the integrated management of A. tuberculatus.

谷物黑麦（SecalealeeL .）作为覆盖作物可以成为作物生产中抑制水麻[ Amaranthus tuberculatus （Moq.）Sauer]的有效非化学工具。先前的研究评估了作为杂草管理计划一部分的谷物黑麦对结核曲霉的抑制作用，但尚未研究覆盖作物抑制结核菌的潜在机制。本研究旨在研究谷物黑麦生物量对结核菌出苗和发育的影响，以及对结核菌萌发关键触发因素土壤环境参数（温度、湿度和透光率）的影响，以阐明黑麦生物量对结核菌萌发的抑制机制。覆盖作物。 2021 年至 2023 年，在威斯康星州布鲁克林和简斯维尔的田间条件下进行了剂量反应研究。在春季花期收获来自秋季播种田地的谷物黑麦生物量，并在 60°C 下干燥至恒重，以提供 0.0、 0.6、1.2、2.4、4.8、7.2、9.6和12.0 Mg ha -1干生物量均匀分布在1.9 m -2 的地块上。增加谷物黑麦生物量会降低结核菌的高度、生物量和密度。需要5.2 Mg ha -1的平均ED 50生物质才能将结核菌密度降低50%。与裸土相比，由于覆盖物下方的土壤湿度增加，低水平的生物量（≤2.38 Mg ha -1）增加了结核菌的密度。谷物黑麦生物量减少了到达土壤的阳光量，导致全天平均土壤温度和温度振幅较低（0 和 12.0 Mg ha -1时温度振幅分别为 9.3 和 2.7 C）。通过这种热效应防止结核菌发芽可能是谷类黑麦覆盖作物抑制结核菌的主要机制。我们的研究结果支持谷物黑麦覆盖作物的生物质能有效抑制结核菌，并有助于结核菌的综合管理。