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Original Article | Open Access

Carbon Footprints

Cui et al. Carbon Footprints 2026, 5, 19 DOI:10.20517/cf.2026.03

Soil inorganic carbon loss offsets organic carbon
sequestration in cropland

Bin Cui, Xiyan Tang, Jie Ma, Lishan Kuang, Ning Yuan, Fanqiao Meng

Keywords:
Long-term experiment,
intensive farming, carbon
conversion efficiency, deep
soil, North China Plain

Citation: Cui, B.; Tang, X.;
Ma, J.; Kuang, L.; Yuan, N.;
Meng, F. Soil inorganic
carbon loss offsets organic
carbon sequestration in
cropland. Carbon Footprints
2026, 5, 19.
https://dx.doi.org/10.20517
/cf.2026.03

Received: 9 Jan 2026
First Decision: 10 Feb
2026 Abstract
Revised: 3 Mar 2026
Accepted: 17 Mar 2026 Agricultural soils are vital for reducing atmospheric CO 2 ; however, the effectiveness of
Published: 10 Apr 2026 farmland carbon sequestration, including soil organic carbon (SOC) and inorganic carbon
(SIC), typically requires a lengthy period and varies with different farming practices. In a
Academic Editor:
Dafeng Hui long-term study on the North China Plain, SOC and SIC changes due to farming practices
Copy Editor: involving N fertilization, organic materials, irrigation, and no-tillage were tracked. Four
Ping Zhang experimental treatments, including no N fertilizer input (CK), local farmer operation (FRM),
Production Editor: optimized farming (OPT), and no-tillage (NoT), were selected for the study. From 2008 to
Ping Zhang
2024, the fertilized treatments sequestered SOC at rates of 0.35-0.63 Mg C ha yr in the
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0-20 cm layer, which quadrupled in the 0-100 cm layer. Long-term high irrigation with N
fertilization accelerated the leaching of SIC into the subsoil, and SIC losses ranged from
0.46 to 0.71 Mg C ha yr at 0-20 cm and from 1.88 to 2.42 Mg C ha yr at 0-100 cm.
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Organic materials and N fertilization interactively help sequester SOC, but excessive
organic material input results lower conversion efficiency. Crucially, the substantial
depletion of SIC across the whole profile largely counteracted the observed SOC gains,
leading to a diminished or even negative net carbon balance. Ultimately, this study reveals
that failing to account for whole-profile SOC-SIC co-dynamics leads to an overestimation
of carbon sequestration in intensive agricultural systems, highlighting the necessity of
integrated accounting for accurate climate mitigation assessments.

Beijing Key Laboratory of Farmland Soil Pollution Prevention and Remediation, College of Resources and Environmental Sciences, China
Agricultural University, Beijing 100193, China.

Correspondence to: Prof. Fanqiao Meng, Beijing Key Laboratory of Farmland Soil Pollution Prevention and Remediation, College of
Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China. E-mail: mengfq@cau.edu.cn

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