Details
| Original language | English |
|---|---|
| Pages (from-to) | 23869-23882 |
| Number of pages | 14 |
| Journal | Environmental Science and Technology |
| Volume | 59 |
| Issue number | 44 |
| Early online date | 30 Oct 2025 |
| Publication status | Published - 11 Nov 2025 |
Abstract
Soil inorganic carbon (SIC), primarily calcite, represents a potentially reactive carbon reservoir, influencing soil–atmosphere CO2exchange and acid–base buffering processes. Though often considered stable, SIC is sensitive to biogenic CO2and acidification, risking extra CO2emissions beyond soil organic matter (SOM) mineralization. This study investigates SIC reactivity using δ13C-enriched calcite (11.9 t ha–1, +102.02‰) under organic residue decomposition, examining the effects of residue type (maize vs wheat), degradability (leaves vs roots), and placement (mixing vs mulching). Incubations at 25 °C with 80% soil–water saturation coupled high-resolution pH optodes and HYDRUS-PHREEQC simulations to quantify SIC reactivity. Mixed applications of labile maize leaves (C:N = 17.3) intensified topsoil (∼50% of the 10 cm column) acid loading (pH 7.9 → 5.7), promoting decarbonation and deepening acidification front (>3.2 cm). Soil respiration emerged as a key influencer of CO2pressures, controlling porewater acid carrying capacity. Dissolution promoters (H2O, H+, and H2CO3) drove topsoil decarbonation (0.84 t C ha–1in mixed profiles vs 0.06 t C ha–1in mulched) and subsoil (5–10 cm) bicarbonate accrual. δ13C tracing showed SIC-sourced CO2peaks (+25 to +51‰, 40–60% contribution) during incubation’s first quarter (∼day 16–24) prior to SOM-domination (0 to −12‰, 20–10%), reflecting a mixed continuum of CO2sources, SC turnover, and climate feedbacks.
Keywords
- bicarbonate export, biogenic CO, carbonate reactivity, inorganic CO, optode technology, reactive transport modeling, residue decomposition, soil inorganic carbon, δC tracing
ASJC Scopus subject areas
- Chemistry(all)
- General Chemistry
- Environmental Science(all)
- Environmental Chemistry
Sustainable Development Goals
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In: Environmental Science and Technology, Vol. 59, No. 44, 11.11.2025, p. 23869-23882.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Modeling Calcite’s Sensitivity to Biogenic CO2Production
T2 - A Pathway to Soil CO2Efflux Partitioning
AU - Tetteh, Kenneth
AU - Guggenberger, Georg
AU - Sauheitl, Leopold
AU - Zamanian, Kazem
N1 - Publisher Copyright: © 2025 The Authors. Published by American Chemical Society
PY - 2025/11/11
Y1 - 2025/11/11
N2 - Soil inorganic carbon (SIC), primarily calcite, represents a potentially reactive carbon reservoir, influencing soil–atmosphere CO2exchange and acid–base buffering processes. Though often considered stable, SIC is sensitive to biogenic CO2and acidification, risking extra CO2emissions beyond soil organic matter (SOM) mineralization. This study investigates SIC reactivity using δ13C-enriched calcite (11.9 t ha–1, +102.02‰) under organic residue decomposition, examining the effects of residue type (maize vs wheat), degradability (leaves vs roots), and placement (mixing vs mulching). Incubations at 25 °C with 80% soil–water saturation coupled high-resolution pH optodes and HYDRUS-PHREEQC simulations to quantify SIC reactivity. Mixed applications of labile maize leaves (C:N = 17.3) intensified topsoil (∼50% of the 10 cm column) acid loading (pH 7.9 → 5.7), promoting decarbonation and deepening acidification front (>3.2 cm). Soil respiration emerged as a key influencer of CO2pressures, controlling porewater acid carrying capacity. Dissolution promoters (H2O, H+, and H2CO3) drove topsoil decarbonation (0.84 t C ha–1in mixed profiles vs 0.06 t C ha–1in mulched) and subsoil (5–10 cm) bicarbonate accrual. δ13C tracing showed SIC-sourced CO2peaks (+25 to +51‰, 40–60% contribution) during incubation’s first quarter (∼day 16–24) prior to SOM-domination (0 to −12‰, 20–10%), reflecting a mixed continuum of CO2sources, SC turnover, and climate feedbacks.
AB - Soil inorganic carbon (SIC), primarily calcite, represents a potentially reactive carbon reservoir, influencing soil–atmosphere CO2exchange and acid–base buffering processes. Though often considered stable, SIC is sensitive to biogenic CO2and acidification, risking extra CO2emissions beyond soil organic matter (SOM) mineralization. This study investigates SIC reactivity using δ13C-enriched calcite (11.9 t ha–1, +102.02‰) under organic residue decomposition, examining the effects of residue type (maize vs wheat), degradability (leaves vs roots), and placement (mixing vs mulching). Incubations at 25 °C with 80% soil–water saturation coupled high-resolution pH optodes and HYDRUS-PHREEQC simulations to quantify SIC reactivity. Mixed applications of labile maize leaves (C:N = 17.3) intensified topsoil (∼50% of the 10 cm column) acid loading (pH 7.9 → 5.7), promoting decarbonation and deepening acidification front (>3.2 cm). Soil respiration emerged as a key influencer of CO2pressures, controlling porewater acid carrying capacity. Dissolution promoters (H2O, H+, and H2CO3) drove topsoil decarbonation (0.84 t C ha–1in mixed profiles vs 0.06 t C ha–1in mulched) and subsoil (5–10 cm) bicarbonate accrual. δ13C tracing showed SIC-sourced CO2peaks (+25 to +51‰, 40–60% contribution) during incubation’s first quarter (∼day 16–24) prior to SOM-domination (0 to −12‰, 20–10%), reflecting a mixed continuum of CO2sources, SC turnover, and climate feedbacks.
KW - bicarbonate export
KW - biogenic CO
KW - carbonate reactivity
KW - inorganic CO
KW - optode technology
KW - reactive transport modeling
KW - residue decomposition
KW - soil inorganic carbon
KW - δC tracing
UR - http://www.scopus.com/inward/record.url?scp=105021380445&partnerID=8YFLogxK
U2 - 10.1021/acs.est.5c07428
DO - 10.1021/acs.est.5c07428
M3 - Article
C2 - 41215687
AN - SCOPUS:105021380445
VL - 59
SP - 23869
EP - 23882
JO - Environmental Science and Technology
JF - Environmental Science and Technology
SN - 0013-936X
IS - 44
ER -