Long-term effects of a one-time application of flue gas desulfurization gypsum on the soil pore structure in sodic paddy fields

Jianzhong Guo; Bangyan Liu; Kangping Zhang; Zhentao Sun; Enbo Mo; Shujuan Wang; Jia Liu; Yan Li; Lizhen Xu; Yonggan Zhao

doi:10.1016/j.agwat.2025.109346

Agricultural Water Management (Mar 2025)

Long-term effects of a one-time application of flue gas desulfurization gypsum on the soil pore structure in sodic paddy fields

Jianzhong Guo,
Bangyan Liu,
Kangping Zhang,
Zhentao Sun,
Enbo Mo,
Shujuan Wang,
Jia Liu,
Yan Li,
Lizhen Xu,
Yonggan Zhao

Affiliations

Jianzhong Guo: Department of Horticulture and Landscape Architecture, Taiyuan University, Shanxi 030032, China
Bangyan Liu: Department of Energy and Power Engineering, Tsinghua University, Beijing 100084, China; Beijing Engineering Research Centre for Ecological Restoration and Carbon Fixation of Saline–Alkaline and Desert Land, Beijing 100084, China; Shanxi Research Institute for Clean Energy of Tsinghua University, Shanxi 030032, China
Kangping Zhang: Department of Horticulture and Landscape Architecture, Taiyuan University, Shanxi 030032, China
Zhentao Sun: Department of Energy and Power Engineering, Tsinghua University, Beijing 100084, China; Beijing Engineering Research Centre for Ecological Restoration and Carbon Fixation of Saline–Alkaline and Desert Land, Beijing 100084, China; Shanxi Research Institute for Clean Energy of Tsinghua University, Shanxi 030032, China
Enbo Mo: Beijing Engineering Research Centre for Ecological Restoration and Carbon Fixation of Saline–Alkaline and Desert Land, Beijing 100084, China; Tsinghua Agriculture Co., Ltd., Beijing 100084, China
Shujuan Wang: Department of Energy and Power Engineering, Tsinghua University, Beijing 100084, China; Beijing Engineering Research Centre for Ecological Restoration and Carbon Fixation of Saline–Alkaline and Desert Land, Beijing 100084, China; Shanxi Research Institute for Clean Energy of Tsinghua University, Shanxi 030032, China; Correspondence to: Department of Energy and Power Engineering, Tsinghua University, No.1 Tsinghua Garden, Haidian District, Beijing 100084, China.
Jia Liu: Beijing Engineering Research Centre for Ecological Restoration and Carbon Fixation of Saline–Alkaline and Desert Land, Beijing 100084, China; Tsinghua Agriculture Co., Ltd., Beijing 100084, China
Yan Li: Department of Energy and Power Engineering, Tsinghua University, Beijing 100084, China; Beijing Engineering Research Centre for Ecological Restoration and Carbon Fixation of Saline–Alkaline and Desert Land, Beijing 100084, China; Shanxi Research Institute for Clean Energy of Tsinghua University, Shanxi 030032, China
Lizhen Xu: Beijing Engineering Research Centre for Ecological Restoration and Carbon Fixation of Saline–Alkaline and Desert Land, Beijing 100084, China; Shanxi Research Institute for Clean Energy of Tsinghua University, Shanxi 030032, China
Yonggan Zhao: Department of Energy and Power Engineering, Tsinghua University, Beijing 100084, China; Beijing Engineering Research Centre for Ecological Restoration and Carbon Fixation of Saline–Alkaline and Desert Land, Beijing 100084, China; Shanxi Research Institute for Clean Energy of Tsinghua University, Shanxi 030032, China; Correspondence to: Department of Energy and Power Engineering, Tsinghua University, No.1 Tsinghua Garden, Haidian District, Beijing 100084, China.

DOI: https://doi.org/10.1016/j.agwat.2025.109346
Journal volume & issue: Vol. 309
p. 109346

Abstract

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Saline–sodic soil suffer from a high content of exchangeable sodium ions in the soil colloid and the poor air and water permeability of the soil pore structure. Flue gas desulfurization (FGD) gypsum improves sodic saline–alkali soil by replacing sodium ions with calcium ions. However, research on the original soil pore structure after the modification of sodic saline–alkali soil with FGD gypsum is limited, especially the subsequent long-term effects on soil pores. In this study, we utilized X-ray computed tomography (CT) scans to analyse undisturbed soil samples from depths of 0–20 cm in fields that were treated once with FGD gypsum and planted with rice for various periods (1 year (T1), 3 years (T3), and 10 years (T10)). Samples from untreated soil (T0) were examined. The volume, distribution, and morphology of the soil pores were compared. The results revealed that FGD gypsum markedly increased the soil total porosity (≥70.65 μm) in the 0–10 cm layer, increasing it by 2.92, 2.76, and 2.37 times 1-, 3-, and 10-years posttreatment, respectively, compared with that in untreated soil. With the extended improvement time, the soil total porosity of the sodic soil treated with FGD gypsum decreased but remained significantly higher than that of the soil without FGD gypsum application. In contrast, the total porosity decreased in the 10–20 cm layer. The number of pores smaller than 1 mm increased in the 0–10 cm layer after the FGD gypsum application. The FGD gypsum treatment predominantly influenced the volume of larger pores (diameter > 2 mm), with a minimal effect on smaller pores. The increases in the fractal dimension and tortuosity after the FGD gypsum treatment indicated the formation of a more complex soil pore structure. FGD gypsum improved the soil pore skeleton network by increasing the thickness of the skeleton network and the number of coordination sites and by reducing the vertical pore angle, thus improving soil aeration and water permeability. These findings confirm that the pore structure of sodic alkaline soils can be significantly improved with a one-time application of FGD gypsum, verifying its long-term advantages.

Published in Agricultural Water Management

ISSN: 1873-2283 (Online)
Publisher: Elsevier
Country of publisher: Netherlands
LCC subjects: Agriculture: Agriculture (General); Social Sciences: Industries. Land use. Labor: Special industries and trades: Agricultural industries
Website: https://www.sciencedirect.com/journal/agricultural-water-management

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