SAINS TANAH - Journal of Soil Science and Agroclimatology
Vol. 23 No. 2 (2026): December

Soil CO2 flux of rewetted small-scale agricultural peatlands in West Kalimantan, Indonesia

Rabbirl Yarham Mahardika (Tanjungpura University)
Suria Darma Tarigan (IPB University)
Dwi Putro Tejo Baskoro (IPB University)
Hummaira Hasnaya Siregar (University of Tanjungpura)
Muhamad Noor Azizu (University of Tanjungpura)
Sultan Aziz Barai (CM World Youth Alliance)



Article Info

Publish Date
01 Jul 2026

Abstract

Indonesia hosts one of the largest tropical peatlands and several parts of which have been converted for agriculture, including small-scale systems. These practices have altered soil and ecological function, shifting their role from long-term carbon sinks into sources of carbon emissions. For years Indonesia employs rewetting as strategies for peatland restoration. This is implemented by constructing canal blocks to elevate the groundwater table (GWT), thereby mitigating carbon emissions. Furthermore, this study analyze soil CO₂ fluxes in rewetted small-scale agricultural peatlands, separating peat- and root-derived emissions to support emission factor refinement. The study conducted in four land uses—horticulture (HOR), rubber (RBB), oil palm (OPP), and secondary forest (DSF) in West Kalimantan, Indonesia. Soil CO₂ fluxes were measured using an Infrared Gas Analyzer with closed-chamber and devices to measured environmental factors. The result shows that the highest soil CO₂ flux was recorded in OPP, while the lowest was observed in DSF. Soil CO₂ flux in HOR, RBB, OPP, and DSF were 46.69, 44.46, 64.55, and 21.68 Mg CO₂ ha⁻¹ yr⁻¹, respectively. GWT was the feature importance influencing soil CO₂ flux in all sites except DSF, where the soil moisture was the feature importance. These findings indicate that the moisture regime plays a crucial role in regulating soil CO₂ flux. When compared with default emission factors from national (2nd FREL) and global systems (IPCC), these findings revealed varying result. These differences explain the complexity of peatlands and highlight the potential value in refining emission estimates, especially for small-scale agricultural systems.

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