Effects of soil organic amendments on soil organic carbon content and molecular diversity at the aggregate level

作者：Li Lin, Wei Ji, Sibei Chen, Jinzhen Zhan, Yue Qiu, Junhui Yin, Yutao Peng, Guitong Li, Xiaorong Zhao, Qimei Lin, Owen S. Fenton, Hao Chen · 发表于：Ecotoxicology and Environmental Safety · 年份：2026 · DOI：10.1016/j.ecoenv.2025.119630 · 被引用次数：3 · 研究领域：Soil Carbon and Nitrogen Dynamics、Composting and Vermicomposting Techniques、Phosphorus and nutrient management

Soil organic matter (SOM) is critical for agroecosystem functions and can be improved by organic amendments. However, the chemical composition of different SOM fractions contained in soil aggregates under soil organic amendments is still unclear. Herein, this issue was addressed with soils sampled from five short-term fertilization regimes including stable (i.e., biochar, C/N ratio of 38.5) and unstable amendments (i.e., manure, C/N ratio of 16.2; food waste compost (FWC), C/N ratio of 5.7) in a vegetable field. The treatments were: (1) 3.4 kg·m −2 manure as control, (2) 5 kg·m −2 biochar + 3.4 kg·m −2 manure, (3) 5 kg·m −2 biochar + 2.26 kg·m −2 manure + 1.14 kg·m −2 FWC, (4) 5 kg·m −2 biochar + 1.7 kg·m −2 manure + 1.7 kg·m −2 FWC, (5) 5 kg·m −2 biochar + 1.14 kg·m −2 manure + 2.26 kg·m −2 FWC. Light (LF) and heavy (HF) fractions of SOM in water-stable aggregates were separated by density fractionation and then characterized for molecular composition using pyrolysis-gas chromatography-mass spectrometry (Py-GC/MS). Results showed that both the proportion of macroaggregates (> 0.25 mm) and aggregate stability (indicated by mean weight diameter) increased with an increasing substitution rate of FWC for manure (i.e., substitution with equal-mass principle). In addition, biochar addition enhanced the LF proportion and the SOC content in LF of both macro- and microaggregates (< 0.25 mm), and these enhancements were not further affected by the FWC substitution for manure. However,...