Microbial necromass carbon and nitrogen persistence are decoupled in agricultural grassland soils
Microbial necromass carbon and nitrogen persistence are decoupled in agricultural grassland soils
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DOI：
10.1038/s43247-022-00439-0
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发表时间：
2022-05
影响因子：
7.9
通讯作者：
Kate M. Buckeridge;Kelly E. Mason;N. Ostle;N. McNamara;H. Grant;J. Whitaker
中科院分区：
文献类型：
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作者：
Kate M. Buckeridge;Kelly E. Mason;N. Ostle;N. McNamara;H. Grant;J. Whitaker
微生物坏死块是土壤有机质的重要组成部分，但其持久性和对土壤固碳的贡献却很少被量化。在此，我们研究了尸块与土壤矿物质的相互作用，并比较了在英格兰西北部低管理强度和高管理强度的草地土壤中，尸块与植物凋落物的持久性。在1年的实验室培养过程中，我们发现植物凋落叶的碳矿化率高于凋落根和坏死块，但1年后碳持久性没有显著差异。在现场实验中，大约三分之二的同位素标记的坏死团碳在3天内与矿物相关。在8个月的时间里，矿物伴生碳的下降速度比氮的下降速度更快，而且随着管理强度的增加，两者的持久性都增强了。我们认为，碳矿化率与碳持久性脱钩，坏死体碳持久性不如坏死体氮持久性，农业管理强度影响草原的碳固存。
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.