title: Short-term effects of tillage practices on soil organic carbon turnover assessed by δ13C abundance in particle-size fractions of black soils from northeast China.
abstract: The combination of isotope trace technique and SOC fractionation allows a better understanding of SOC dynamics. A five-year tillage experiment consisting of no-tillage (NT) and mouldboard plough (MP) was used to study the changes in particle-size SOC fractions and corresponding δ (13)C natural abundance to assess SOC turnover in the 0-20 cm layer of black soils under tillage practices. Compared to the initial level, total SOC tended to be stratified but showed a slight increase in the entire plough layer under short-term NT. MP had no significant impacts on SOC at any depth. Because of significant increases in coarse particulate organic carbon (POC) and decreases in fine POC, total POC did not remarkably decrease under NT and MP. A distinct increase in silt plus clay OC occurred in NT plots, but not in MP plots. However, the δ (13)C abundances of both coarse and fine POC increased, while those of silt plus clay OC remained almost the same under NT. The C derived from C3 plants was mainly associated with fine particles and much less with coarse particles. These results suggested that short-term NT and MP preferentially enhanced the turnover of POC, which was considerably faster than that of silt plus clay OC.
authors.affiliation: Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, China.
authors.forename: Aizhen
authors.identifier: 0000-0001-9990-4840
authors.initials: A
authors.lastname: Liang
authors.affiliation: Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, China ; University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Shenglong
authors.identifier: 0000-0001-7457-0266
authors.initials: S
authors.lastname: Chen
authors.affiliation: Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, China.
authors.forename: Xiaoping
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, China.
authors.forename: Xuewen
authors.initials: X
authors.lastname: Chen
mesh_terms: D000383:Agriculture / Q000379:methods*; D002244:Carbon / Q000032:analysis*; D005591:Chemical Fractionation; D002681:China; D004784:Environmental Monitoring; D010316:Particle Size; D012987:Soil / Q000737:chemistry*
chemical_list: D012987:Soil; D002244:Carbon