Details

Autor(en) / Beteiligte

• Guo, Lingke
• Shen, Jie
• Li, Bing
• Li, Qiquan
• Wang, Changquan
• Guan, Yu
• D'Acqui, Luigi P.
• Luo, Youlin
• Tao, Qi
• Xu, Qiang
• Li, Huanxiu
• Yang, Juan
• Tang, Xiaoyan

Titel

Impacts of agricultural land use change on soil aggregate stability and physical protection of organic C

Ist Teil von

• The Science of the total environment, 2020-03, Vol.707, p.136049-136049, Article 136049

Ort / Verlag

Netherlands: Elsevier B.V

Erscheinungsjahr

2020

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Soil aggregate stability and soil organic carbon (SOC) physical sequestration is essential to regulation of anthropogenic climate change. However, relative knowledge remains elusive. The total SOC stock, aggregate stability, capacity of physically protected C, structure of macroaggregates and Al/Fe oxides under rice-wheat rotation (RW), rice-vegetable rotation (RV) and afforested land (AL) were analysed. We chose 1–2 mm macroaggregates for low-temperature ashing (LTA) treatment to mimic natural oxidation to assess the capacity of physically protected C. Using scanning electron microscopy, the N adsorption method, and energy dispersive spectroscopy, we explored the internal structure of macroaggregates under different land use types. All land use types could physically protect over 50% of SOC. AL showed the strongest capacity of C sequestration, followed by RW, which preserved 67.1% and 59.6% of SOC, respectively. After 5 h of LTA treatment, the amount of SOC removed from the macropores in cropland (RW and RV) was higher than that in AL. In micropores with further oxidation, AL and RW both lost only 5% of SOC. Fe oxides were more correlated with C dynamics than Al oxides. Free Fe oxides were associated with the easily oxidised organic matter. Soil aggregate stability significantly correlated with Al/Fe oxides (p < 0.05). The RW and AL had a greater soil aggregate stability than the RV owing to the relatively higher content of Al/Fe oxides. In conclusion, the conversion of RW to RV reduced the mechanical stability of soil aggregates and the capacity of C physical sequestration, while the conversion of RW to AL increased these two properties. Land use change affected C physical sequestration mainly via changes in surface area, pore development and the content of Fe oxides in macroaggregates. [Display omitted] •1–2 mm macroaggregates physically protected >50% of C•Macroaggregate structure was a key factor affecting the physical C sequestration capacity.•LTA could simulate the continuous oxidation process of Al/Fe oxides.•Fe-DCB was mainly associated with easily oxidised organic matter.•The differences of C sequestration and aggregate stability were linked to Al/Fe oxides changed.