Data for: Cover crop functional types differentially alter the content and composition of soil organic carbon in particulate and mineral-associated fractions

Cover crops (CCs) can increase soil organic carbon (SOC) sequestration by providing additional OC residues, recruiting beneficial soil microbiota, and improving soil aggregation and structure. The various CC species that belong to distinct plant functional types (PFTs) may differentially impact SOC formation and stabilization. Biogeochemical theory suggests that selection of PFTs with distinct litter quality (C:N ratio) should influence the pathways and magnitude of SOC sequestration. Yet, we lack knowledge on the effect of CCs from different PFTs on the quantity and composition of physiochemical pools of SOC. We sampled soils under monocultures of three CC PFTs (legume [crimson clover]; grass [triticale]; and brassica [canola]) and a mixture of these three species, from a long-term CC experiment in Pennsylvania, USA. We measured C content in bulk soil and C content and composition in contrasting physical fractions: particulate organic matter, POM; and mineral-associated organic matter,..., ,

覆盖作物（Cover Crops, CCs）可通过额外输入有机碳残体、招募有益土壤微生物群落、改善土壤团聚体结构与稳定性，提升土壤有机碳（Soil Organic Carbon, SOC）固存能力。隶属于不同植物功能型（Plant Functional Types, PFTs）的各类覆盖作物物种，对土壤有机碳形成与稳定的影响可能存在差异。生物地球化学理论表明，选择具有不同枯落物质量特征（碳氮比，C:N ratio）的植物功能型，会影响土壤有机碳固存的途径与固存规模。然而，目前我们仍缺乏对不同植物功能型覆盖作物如何影响土壤有机碳物理化学组分库的数量与组成的认知。我们从美国宾夕法尼亚州的长期覆盖作物试验田中，采集了三种覆盖作物植物功能型单作样地（豆科[绛三叶]、禾本科[小黑麦]、十字花科[油菜]）以及这三个物种混合样地的土壤样品。我们测定了原状土壤的碳含量，以及两类物理分级组分中有机质的碳含量与组成：颗粒态有机质（Particulate Organic Matter, POM）与矿质结合态有机质……