Plant residue quality regulates its incorporation into soil aggregates and organic carbon stabilisation
Plant residue input is vital for soil organic carbon (SOC) formation and stabilisation. While soil aggregates serve as fundamental units for SOC physical stabilisation, residue-derived C distribution among aggregate fractions and the factors regulating this complex process remain unclear. In this st...
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| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Elsevier
2025-08-01
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| Series: | Geoderma |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S0016706125002459 |
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| Summary: | Plant residue input is vital for soil organic carbon (SOC) formation and stabilisation. While soil aggregates serve as fundamental units for SOC physical stabilisation, residue-derived C distribution among aggregate fractions and the factors regulating this complex process remain unclear. In this study, the effect of plant quality on the distribution of residue-derived C within soil aggregates was evaluated in a 120-day incubation experiment using various parts of 13C-labeled maize straw (root, stem, leaf, sheath, husk, and cob; P content: 0.04–0.11 %; cellulose content: 25–33 %). Residue-derived C flow was divided into three stages: partitioning, transformation, and stabilisation. In the partitioning stage, residue-derived C was initially distributed across all aggregate fractions and subsequently declined in all fractions due to residue decomposition and CO2 emissions. In the transformation phase, the 13C content in small macroaggregates increased by 0.13 g 13C kg−1, reflecting transfer from other aggregate fractions. Finally, residue-derived C in small macroaggregates was further transferred to the silt + clay-sized fraction. The residue hemicellulose content was positively correlated with 13C transfer into large macroaggregates and the silt + clay-sized fraction in the partitioning stage. In the transformation phase, residue-derived 13C in small macroaggregates increased with increasing plant P contents. During the stabilisation stage, the cellulose content was negatively correlated with 13C in the silt + clay-sized fraction. This study highlighted three critical stages of residue-derived C dynamics in soil aggregates during decomposition and identified plant P and cellulose contents as key regulators of residue-derived C stabilisation in soil aggregates. |
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| ISSN: | 1872-6259 |