CAREER: Digging deeper to the roots of soil organic carbon formation, persistence, and function: An integrated research, education, and outreach program.

土壤有机碳（SOC）对可持续粮食生产至关重要，因为它可以改善养分和水分的保持，增强土壤的生物活性。有机碳还可以帮助缓解气候变化，因为它可以作为大气二氧化碳的汇。由于集约化管理措施，许多生态系统土壤的有机碳已经耗尽。植物是一个重要的途径，通过微生物分解的茎和根组织，大气中的碳可以被引导到有机碳。因此，使用多种植物混合物等再生做法可能会提高受管理生态系统的有机碳。然而，深入了解有机碳是如何形成的，更重要的是，这些新形成的碳在哪里被封存，对于制定有关植物物种多样性的明智决策以提高有机碳含量至关重要。本研究探讨了具有不同茎和根化学成分的不同植物混合物如何与土壤微生物和土壤矿物质相互作用，从而影响生态系统中有机碳的形成、持久性和功能（如养分有效性）。这项研究与教育和推广活动相结合，同时确保代表性不足的群体参与科学。教育活动包括面向K-12和大学生的研究培训和体验式学习机会，以及面向本科生和研究生的新土壤课程。有机碳是高度异质性的，由植物和微生物生物量分解产生的大量生物分子可以被隔离在不同的土壤组分中。在预估的变暖情景下，储存在不同物理组分中的有机碳，如颗粒有机质（POM；短期固存）和矿物相关有机质（MAOM；长期固存），将调节有机碳的持久性。该研究评估了植物组织类型和植物功能类型如何影响POM和MAOM组分中溶解有机质的形成和化学组成，以及这些植物因子与微生物参数和土壤矿物学对有机碳形成、持久性和功能的相互作用。本研究采用多因素实验室、温室、多站点现场实验和先进的分析技术，从分子水平上了解生态系统有机碳动态。研究和推广活动与K-12，本科生和研究生的跨学科培训相结合。该研究提供了对有机碳形成过程的机制理解，并为基于知识的管理实践提供了信息，以增强生态系统中有机碳的封存、持久性和功能。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Soil organic carbon (SOC) is critical for sustainable food production as it improves nutrient and water retention and enhances soil biological activity. SOC can also help mitigate climate change as it can act as a sink for atmospheric carbon dioxide. Soils in many ecosystems are depleted in SOC due to intensive management practices. Plants are a significant pathway through which atmospheric carbon can be channeled to SOC through the microbial decomposition of the shoot and root tissues. Thus, regenerative practices such as using diverse plant mixtures can potentially enhance SOC in managed ecosystems. However, obtaining a deeper understanding of how SOC is formed and, more importantly, where this newly formed carbon is sequestered, is critical to making informed decisions regarding plant species diversity for enhancing SOC. This research investigates how diverse plant mixtures with varying shoot and root chemistry interact with soil microbes and soil minerals to influence the formation, persistence, and function (e.g., nutrient availability) of SOC in ecosystems. The research is integrated with education and outreach activities while ensuring the participation of underrepresented groups in science. The educational activities include research training and experiential learning opportunities for K-12 and college students, and a new soils course for undergraduate and graduate students.SOC is highly heterogenous, with a multitude of biomolecules resulting from the decomposition of plant and microbial biomass that can be sequestered in different soil fractions. SOC stored in different physical fractions, such as particulate organic matter (POM; short-term sequestration) and mineral-associated organic matter (MAOM; long-term sequestration), will regulate the persistence of SOC under projected warming scenarios. The research evaluates how plant tissue type and plant functional type affect dissolved organic matter formation and chemical composition and, in turn, the interaction of these plant factors with microbial parameters and soil mineralogy to SOC formation, persistence, and function in POM and MAOM fractions. The research uses multifactor lab, greenhouse, multi-site field experiments, and advanced analytical techniques to obtain a molecular-level understanding of SOC dynamics in ecosystems. The research and outreach activities are integrated with cross-disciplinary training for K-12, undergraduate, and graduate students. The research provides a mechanistic understanding of SOC formation processes and informs knowledge-based management practices to enhance SOC sequestration, persistence, and function in ecosystems.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.