A 2-year outdoor mesocosm experiment was carried out to determine the effects of high C amendments (HCAs; wheat straw and sawdust) compared to a control with no addition of HCAs (no-HCA) and 2 different crop rotation systems (spring barley/winter barley and faba bean/winter barley) on soil bacterial communities using a molecular barcoding approach. Samples were analyzed after pre-crop harvest (T1) and harvest of winter barley (T2). Our data demonstrate a clear drop in bacterial diversity after winter barley harvest in the no-HCA and wheat straw treatment compared to the pre-crops. Sawdust application had a stabilizing effect on bacterial diversity compared to the pre-crops and induced an increase in carbon (C) stocks in soil which were however negatively correlated with yields. Main responders in the no-HCA and wheat straw treatment compared to the pre-crops were bacteria of the phyla Actinobacteria and Bacteroidetes which were enriched and bacteria belonging to Firmicutes, Gemmatimonadetes, Proteobacteria, and Gemmatimonadaceae which were depleted. Overall differences between wheat straw–amended and no-HCA control samples were small and included single ASVs from various phyla. In sawdust-amended samples, only a shift of some Proteobacteria families was observed compared to the no-HCA control. Overall, pre-crop plant species had small influence on the observed response pattern of the soil microbiome towards the amendments and was only visible for wheat straw.

中文翻译：

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高碳改良剂和作物前期对土壤细菌群落的影响

进行了为期 2 年的户外中观实验，以确定与不添加 HCA（无 HCA）和 2 种不同作物轮作系统（春大麦/冬大麦和蚕豆/冬大麦）使用分子条形码方法对土壤细菌群落进行分析。在作物前收获 (T1) 和冬大麦收获 (T2) 后分析样品。我们的数据表明，与作物前相比，在无 HCA 和小麦秸秆处理中，冬季大麦收获后细菌多样性明显下降。与作物前相比，锯末施用对细菌多样性具有稳定作用，并导致土壤中碳 (C) 储量的增加，但与产量呈负相关。与作物前相比，无 HCA 和小麦秸秆处理中的主要反应物是富集的放线菌门和拟杆菌门的细菌，以及枯竭的厚壁菌门、Gemmatimonadetes、Proteobacteria 和 Gemmatimonadaceae 的细菌。小麦秸秆改良和无 HCA 对照样品之间的总体差异很小，包括来自各种门的单个 ASV。在锯末修正的样品中，与无 HCA 对照相比，仅观察到一些变形菌家族的变化。总体而言，作物前植物物种对观察到的土壤微生物群对修正物的响应模式影响很小，并且仅对小麦秸秆可见。和 Gemmatimonadaceae 枯竭。小麦秸秆改良和无 HCA 对照样品之间的总体差异很小，包括来自各种门的单个 ASV。在锯末修正的样品中，与无 HCA 对照相比，仅观察到一些变形菌家族的变化。总体而言，作物前植物物种对观察到的土壤微生物群对修正物的响应模式影响很小，并且仅对小麦秸秆可见。和 Gemmatimonadaceae 枯竭。小麦秸秆改良和无 HCA 对照样品之间的总体差异很小，包括来自各种门的单个 ASV。在锯末修正的样品中，与无 HCA 对照相比，仅观察到一些变形菌家族的变化。总体而言，作物前植物物种对观察到的土壤微生物群对修正物的响应模式影响很小，并且仅对小麦秸秆可见。