The mineralization and sequestration of organic carbon in relation to agricultural soil erosion

• Published in: Geoderma Vol. 329; pp. 73 - 81
• Main Authors: Xiao, Haibing, Li, Zhongwu, Chang, Xiaofeng, Huang, Bin, Nie, Xiaodong, Liu, Chun, Liu, Lin, Wang, Danyang, Jiang, Jieyu
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.11.2018
• Subjects: agricultural land; agricultural soils; Carbon cycle; carbon sinks; community structure; enzyme activity; global carbon budget; interrill erosion; Mineralization; Sequestration; soil biological properties; Soil erosion; Soil organic carbon; soil slaking; species diversity; Carbon cycle; Soil erosion; Mineralization; Soil organic carbon; Sequestration
• ISSN: 0016-7061; 1872-6259
• DOI: 10.1016/j.geoderma.2018.05.018

The coupling of soil erosion (especially interrill erosion by water) and the dynamics of soil organic carbon (SOC) in agricultural landscapes has been widely studied over the past two decades. To date, however, the role of soil erosion in global C cycle remains a topic of debate. Numerous questions remain to be addressed before determining the C sink/source effect of soil erosion, especially for the mineralization and sequestration of eroded SOC upon erosion, transport and deposition. In this review, we provide a comprehensive cross-disciplinary review on SOC mineralization and sequestration at sites of erosion, along the transport pathway and at depositional sites. The current state of knowledge on the impacts of erosion-induced soil aggregate breakdown and formation, removal of SOC from eroding sites and deep burial of SOC at depositional sites on the mineralization and sequestration of SOC are presented. Furthermore, we provide an overview of the conceptual relations between soil biological properties (microbial abundance, species diversity, community composition and enzyme activity) and the mineralization and sequestration of SOC in eroded agricultural landscapes, which are often overlooked by previous research and reviews. The comprehensive understanding of physical, chemical and biological mechanisms affecting the mineralization and sequestration of eroded SOC provides important insights to balance the global carbon budget and finally holds the answer on the carbon sink/source controversy. •Dynamic replacement of OC at eroding site induces a positive priming effect•Erosion-induced decline in fungal:bacterial ratio increases SOC turnover rate•The breakdown of soil aggregates during transport accelerates SOC mineralization•Deep burial of eroded SOC prolongs its mean residence time in soil•High enzyme activities at depositional sites negatively impact SOC sequestration