U.S. Department of Agriculture, Agricultural Research Service, National Center for Agricultural Utilization Research, Crop Bioprotection Research Unit, Peoria, Illinois, United States of America.
School of Biological Sciences, Illinois State University, Normal, Illinois, United States of America.
PLoS One. 2024 Sep 12;19(9):e0308668. doi: 10.1371/journal.pone.0308668. eCollection 2024.
Despite the well documented link between cover cropping and soil microbiology, the influence of specific cover crop species on soil microbes remains poorly understood. We evaluated how soil fungal communities in a no till system respond to four cover crop treatments: no cover crop (REF), cereal ryegrass (CRYE), wild pennycress (WPEN), and a mix of pea, clover, radish, and oat (PCRO). Soil samples were collected from experimental plots following termination of cover crops from depths of 0-2 cm and 2-4 cm where cover crops had significantly increased soil organic matter. There was no significant interaction between soil depth and cover crop treatment on either alpha diversity or beta diversity. All cover crop treatments (CRYE, PCRO, and WPEN) enhanced soil fungal richness but only CRYE enhanced soil fungal diversity and altered the fungal community structure. Soil depth altered the fungal community structure but had no effect on fungal diversity and richness. Genus Fusarium which includes some of the most economically destructive pathogens was more abundant in REF and PCRO treatments compared to CRYE and WPEN. In contrast, genus Mortierella which is known to promote plant health was more abundant in all cover crop treatments relative to the REF. These findings demonstrate that cover cropping can increase soil fungal species richness and alter fungal community structure, potentially promoting the abundance of beneficial fungi and reducing the abundance of some plant pathogens within the genus Fusarium. These effects are dependent on cover crop species, a factor that should be considered when selecting appropriate cover crops for a particular cropping system.
尽管已经有充分的文献证明覆盖作物与土壤微生物学之间存在关联，但特定覆盖作物物种对土壤微生物的影响仍知之甚少。我们评估了免耕系统中土壤真菌群落对四种覆盖作物处理的反应：无覆盖作物（REF）、黑麦草（CRYE）、野生芝麻菜（WPEN）和豌豆、三叶草、萝卜和燕麦的混合物（PCRO）。在覆盖作物结束后，从 0-2 厘米和 2-4 厘米的深度从实验田采集土壤样本，其中覆盖作物显著增加了土壤有机质。土壤深度和覆盖作物处理对 alpha 多样性或 beta 多样性都没有显著的相互作用。所有覆盖作物处理（CRYE、PCRO 和 WPEN）都增加了土壤真菌丰富度，但只有 CRYE 增加了土壤真菌多样性并改变了真菌群落结构。土壤深度改变了真菌群落结构，但对真菌多样性和丰富度没有影响。属包括一些最具经济破坏性的病原体的镰刀菌在 REF 和 PCRO 处理中比 CRYE 和 WPEN 更丰富。相比之下，已知能促进植物健康的被毛霉属在所有覆盖作物处理中相对 REF 更为丰富。这些发现表明，覆盖作物可以增加土壤真菌物种丰富度并改变真菌群落结构，可能促进有益真菌的丰度并减少属镰刀菌中一些植物病原体的丰度。这些影响取决于覆盖作物的种类，在为特定种植系统选择合适的覆盖作物时，应考虑这一因素。
