Roots play an important role in the formation and turnover of soil organic matter (SOM). Biological processes in the rhizosphere have the capacity to regulate the input of root materials to soil and the fate of root-derived carbon (C) in soil. While some aspects of rhizosphere ecology have received considerable research attention, one potentially important biotic driver, root herbivory, has been largely overlooked. In this study, we first review the literature on root herbivory, revealing that belowground herbivores can have substantial effects on the quality, quantity, and timing of belowground plant inputs to soil. Next, we introduce a conceptual framework in which root herbivory presents a distinct conduit that transfers C from living plants (the “green” world) to soil (the “brown” world). We also argue that direct and indirect interactions between root herbivores and the rhizosphere microbiome and other soil fauna can have significant impacts on soil microbial activities and soil C cycling. Finally, we outline key questions and topics for future research that incorporate belowground plant-herbivore interactions into soil biogeochemistry in an effort to improve our understanding of C flow in the rhizosphere and sharpen future predictions of soil C storage under changing environments.

根在土壤有机质（SOM）的形成和周转中起着重要作用。根际中的生物过程具有调节根系物质向土壤的输入以及土壤中根系碳（C）命运的能力。尽管根际生态学的某些方面受到了相当多的研究关注，但一种潜在的重要生物驱动力，根食草却被大大忽略了。在这项研究中，我们首先回顾了有关根食草的文献，揭示了地下食草动物可能对地下植物向土壤中投入的质量，数量和时间产生重大影响。接下来，我们介绍一个概念框架，在该框架中，根食草动物提供了一条独特的管道，将C从活植物（“绿色”世界）转移到土壤（“棕色”世界）。我们还认为，根草食动物与根际微生物组和其他土壤动物之间的直接和间接相互作用可能会对土壤微生物活动和土壤碳循环产生重大影响。最后，我们概述了未来研究的关键问题和主题，将地下植物与草食动物之间的相互作用纳入土壤生物地球化学中，以增进我们对根际中碳流的理解，并完善在变化的环境中对土壤碳储量的未来预测。