Dynamics of soil aggregate‐associated carbon as influenced by simulated tillage and runoff
(2022) Soil Science Society of America Journal — Vol. 86, n° 6, p. 1457-1469 (2022)
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- Authors
Li, Lu 
- Abstract
- Tillage practices and water erosion are the most important anthropogenic and naturalprocesses, respectively, driving soil organic C turnover in agricultural land. The aimof this study was to explore the responses of soil organic C (SOC) turnover to tillageand runoff by comparing the variation of soil aggregate-associated organic C (AOC)and intra-aggregate particulate organic C (iPOC) under simulated tillage and runoffconditions. Soil samples were collected from a native vegetation land with no culti-vation history in the Mollisol region of Northeast China. After a series of simulatedtillage (ST) and simulated runoff (SR) treatments, the samples were incubated for30 d and then separated through 2-, 1-, 0.25-, and 0.053-mm sieves by wet-sieving toobtain different aggregate size fractions. Each aggregate fraction was subsequentlyshaken for 18 h in 0.5% hexametaphosphate to get different intra-aggregate particlesize fractions. The proportion of the fractions and their AOC and iPOC were deter-mined. The ST treatment promoted the reaggregation of macroaggregates (>2 mm)by accelerating the turnover of their coarse iPOC (0.25–2 mm), leading to a lowerconcentration of AOC. Runoff transformed larger aggregates (>0.25 mm) to smallerparticles (<0.25 mm) without catalyzing C turnover. Fine iPOC (0.053–0.25 mm)could serve as an indicator for AOC (>1 mm) dynamics, especially associated withtillage operations. Our findings highlight the different influences of tillage and runoff,and the negative effect of tillage on SOC dynamics.
- Affiliations
Northeast Forestry University
Citations
Li, L., Wang, E., Cao, W., Zhao, P., Lin, L., Zhai, G., & Cruse, R. M. (2022). Dynamics of soil aggregate‐associated carbon as influenced by simulated tillage and runoff. Soil Science Society of America Journal, 86(6), 1457-1469. https://doi.org/10.1002/saj2.20460 (Original work published 2022)