Nsabimana et al. (2026) Assessing the impacts of wetting and drying cycles on soil aggregate structure. A global meta-analysis study

Identification

• Journal: Journal of Environmental Management
• Year: 2026
• Date: 2026-01-01
• Authors: Gratien Nsabimana, Yuhai Bao, Xiubin He, Jean de Dieu Nambajimana, Bernard Musana Segatagara, Haozhe Zhang, Nsharwasi Léon Nabahungu, Dil Khurram
• DOI: 10.1016/j.jenvman.2026.128572

Research Groups

• Key Laboratory of Mountain Surface Processes and Ecological Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu, 610299, Sichuan, China
• University of Chinese Academy of Sciences, 100049, Beijing, China
• Research for Sustainable Agriculture and Environmental Conservation (RSAEC), P.O. Box: 1280, Rwanda, Kigali
• Rwanda Water Resources Board, P.O.Box: 6213, Kigali, Kigali, Rwanda
• International Institute of Tropical Agriculture (IITA), P.O. Box: 1269, Rwanda, Kigali
• College of Ecology and Environment, Chengdu University of Technology, Chengdu, 610059, China

Short Summary

This global meta-analysis synthesized 659 observations to unify understanding of wetting and drying cycle (WDC) impacts on soil structure, revealing that WDCs significantly degrade soil aggregate stability while increasing porosity.

Objective

• To provide a unified understanding of wetting and drying cycles (WDCs) impacts on soil structure and determine how these effects vary under different soil properties and climatic conditions.

Study Configuration

• Spatial Scale: Global (meta-analysis of existing studies)
• Temporal Scale: Not explicitly defined for the meta-analysis itself, but covers findings from studies over various periods.

Methodology and Data

• Models used: Meta-analysis (statistical synthesis)
• Data sources: 659 paired observations from 26 individual studies (literature review)

Main Results

• Wetting and drying cycles (WDCs) significantly decreased soil aggregate stability, with effect sizes of −28.45 % for mean weight diameter (MWD), −17.13 % for geometric mean diameter (GMD), and −13.43 % for water stable aggregate (WSA).
• WDCs induced a significant decrease in macroaggregates (>0.25 mm) by −24.57 % and an increase in microaggregates (<0.25 mm) by 17.32 %.
• Aggregate degradation increased with the number of WDCs under high mean annual precipitation (>1000 mm/year) and mean annual temperature (>15 °C), showing highest decreases of −52.87 % and −64.1 % for [10–15] cycles compared to marginal decreases of −16.48 % and −15.04 % for [1–3] cycles, respectively.
• Decrease in MWD and macroaggregates under WDCs was lower in soil with soil organic carbon (SOC) >10 g/kg compared to <10 g/kg.
• Clay content showed a positive and significant correlation with MWD and macroaggregate effect sizes.
• The overall effect of WDCs on total pore numbers (TPoN) and total porosity (TPo) was positive, suggesting an increase in porosity and pore numbers.

Contributions

• Provides scientific evidence that WDCs degrade soil structure, highlighting negative implications for the environment due to potential increases in soil erosion.
• Offers a unified understanding of WDC impacts on soil structure by synthesizing inconsistent findings from previous studies.
• Identifies how WDC effects vary under different soil properties (SOC, clay content) and climatic conditions (mean annual precipitation, mean annual temperature).

Funding

• Not specified in the provided text.

Citation

@article{Nsabimana2026Assessing,
  author = {Nsabimana, Gratien and Bao, Yuhai and He, Xiubin and Nambajimana, Jean de Dieu and Segatagara, Bernard Musana and Zhang, Haozhe and Nabahungu, Nsharwasi Léon and Khurram, Dil},
  title = {Assessing the impacts of wetting and drying cycles on soil aggregate structure. A global meta-analysis study},
  journal = {Journal of Environmental Management},
  year = {2026},
  doi = {10.1016/j.jenvman.2026.128572},
  url = {https://doi.org/10.1016/j.jenvman.2026.128572}
}