Microbial necromass carbon and nitrogen persistence are decoupled in agricultural grassland soils

作者：Kate M. Buckeridge, Kelly E. Mason, Nick Ostle, Niall P. McNamara, Helen Grant, Jeanette Whitaker · 发表于：Communications Earth & Environment · 年份：2022 · DOI：10.1038/s43247-022-00439-0 · 被引用次数：66 · 研究领域：Soil Carbon and Nitrogen Dynamics、Forest Ecology and Biodiversity Studies、Soil erosion and sediment transport

Abstract Microbial necromass is an important component of soil organic matter, however its persistence and contribution to soil carbon sequestration are poorly quantified. Here, we investigate the interaction of necromass with soil minerals and compare its persistence to that of plant litter in grassland soils under low- and high-management intensity in northwest England. During a 1-year laboratory-based incubation, we find carbon mineralization rates are higher for plant leaf litter than root litter and necromass, but find no significant difference in carbon persistence after 1 year. During a field experiment, approximately two thirds of isotopically-labelled necromass carbon became mineral-associated within 3 days. Mineral-associated carbon declined more rapidly than nitrogen over 8 months, with the persistence of both enhanced under increased management intensity. We suggest that carbon mineralisation rates are decoupled from carbon persistence and that necromass carbon is less persistent than necromass nitrogen, with agricultural management intensity impacting carbon sequestration in grasslands.