Diversification of agricultural practices, including changes in crop rotation, intercropping or cover cropping, influence the soil microbiome. Here the impact of tillage and crop diversification on the soil microbiome is reported, being one of the few boreal studies. The field experiment consisted of four treatments with four replications all having a short cereal rotation practice namely an oat (Avena sativa) – spring barley (Hordeum vulgare) – wheat (Triticum aestivum) rotation for the past 10 years until spring 2018. During that period two of the treatments were conventionally tilled with moldboard ploughing whereas the other two were no-tillage treatments. From the growing season 2018 until fall 2020 the main crop in all treatments was spring barley. The first conventional tillage treatment was diversified with English ryegrass (Lolium perenne) as an undersown cover crop for the next three growing seasons. The first no-tillage treatment continued with spring barley only. The second conventional tillage and no-tillage treatment had winter rapeseed in rotation in 2019. Bulk soils were sampled in May 2018 before diversification and then in October 2018, 2019, and 2020. The results showed a clear effect of tillage on the beta-diversity of the soil microbiome and an increase in fungal richness. Barley monoculture interrupted with winter rapeseed resulted in a minor change of the fungal and bacterial community composition. Other fungal and bacterial alpha diversity measures did not react to tillage or diversification nor did the gene copy abundances involved in the N cycle. In conclusion tillage had a profound effect on the soil microbiome hindering impact of the diversification.

农业实践的多样化，包括作物轮作、间作或覆盖作物的变化，会影响土壤微生物组。这里报告了耕作和作物多样化对土壤微生物组的影响，这是为数不多的北方研究之一。田间试验包括四个处理和四个重复，所有处理都进行短暂的谷物轮作实践，即过去 10 年直至 2018 年春季的燕麦 ( Avena sativa ) – 春大麦 ( Hordeum vulgare ) – 小麦 ( Triticum aestivum ) 轮作。其中两个处理采用传统的犁耕方式进行耕作，而另外两个处理则采用免耕处理。从 2018 年生长季到 2020 年秋季，所有处理的主要作物都是春大麦。第一个传统的耕作方法是使用英国黑麦草（黑麦草）作为接下来三个生长季节的地下覆盖作物。第一次免耕处理仅用春大麦继续进行。第二次常规耕作和免耕处理于2019年轮作冬油菜。2018年5月在多样化之前对大块土壤进行了采样，然后在2018年10月、2019年和2020年进行了采样。结果显示耕作对β多样性有明显的影响土壤微生物组的变化和真菌丰富度的增加。用冬季油菜籽中断大麦单一栽培导致真菌和细菌群落组成发生微小变化。其他真菌和细菌α多样性测量对耕作或多样化没有反应，也没有参与氮循环的基因复制丰度。总之，耕作对土壤微生物组具有深远的影响，阻碍了多样化的影响。