- Title
- Decomposition of soil organic matter as affected by clay types, pedogenic oxides and plant residue addition rates
- Creator
- Singh, Mandeep; Sarkar, Binoy; Bolan, Nanthi S.; Ok, Yong Sik; Churchman, Gordon Jock
- Relation
- Journal of Hazardous Materials Vol. 374, p. 11-19
- Publisher Link
- http://dx.doi.org/10.1016/j.jhazmat.2019.03.135
- Publisher
- Elsevier
- Resource Type
- journal article
- Date
- 2019
- Description
- The interactive effects of the types and contents of soil clay fractions (SCFs) and plant-residue addition rates on soil organic carbon (SOC) stabilisation are largely unknown. We conducted incubation experiments by amending a sandy soil sample with kaolinitic-illitic, smectitic and allophanic SCFs and adding wheat residues to the mineral mixtures to compare their C stabilisation capacity. The rate of carbon (C) decomposition was higher in the kaolinitic-illitic SCF followed by smectitic and allophanic clay minerals. The supply of easily degradable C substrate from decomposing residues markedly influenced the SCFs' abilities to stabilise SOC. The removal of sesquioxides from the SCFs significantly decreased their C stabilisation capacity, which coincided with a decrease in the dehydrogenase activity of the mineral-residue mixture. The allophanic SCF showed the least microbial activity and the greatest C stabilisation due to having a higher proportion of micropores (75%). The high C stabilisation capacity of allophanic SCF could also be explained by its high specific surface area (119 m 2 g -1 ). The results of this study are helpful to understand the role of various SCFs in stabilising added C originating from external wheat residue addition but warrant further validation under field conditions.
- Subject
- soil clay fractions; wheat plant residue; respiration; organic carbon stabilisation; microbial activity
- Identifier
- http://hdl.handle.net/1959.13/1424595
- Identifier
- uon:38109
- Identifier
- ISSN:0304-3894
- Language
- eng
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